Report on Proposed GPS Instrument Approach at Little River Airport

4/6/97

(rough draft, not yet approved)

1. Summary...................................................................................................................................................................

2. Introduction........................................................................................................................................................

2.1 IFR vs VFR..............................................................................................................................................................

2.2 About Instrument Approach Procedures.....................................................................................

3. Issues Surrounding the Proposed GPS Approach.....................................................................

3.1 Increased Traffic and Noise................................................................................................................

3.2 Altimeter Settings.....................................................................................................................................

3.2.1 Liability........................................................................................................................................................

3.2.2 Cost...............................................................................................................................................................

3.2.3 Recommendation for the Future..............................................................................................................

3.2.4 When the Altimeter Setting is not available..........................................................................................

3.3 FAR 77 Surfaces.............................................................................................................................................

3.3.1 Topping or Cutting Trees.........................................................................................................................

3.4 Runway Protection Zones (Clear Zones).....................................................................................

3.4.1 land purchases............................................................................................................................................

3.5 Moving the road..........................................................................................................................................

3.6 Airspace............................................................................................................................................................

3.6.1 Limited number of IFR operations here.................................................................................................

3.6.2 Scud Running..............................................................................................................................................

3.6.3 Airspace Protection...................................................................................................................................

3.7 New Equipment Purchases.....................................................................................................................

3.8 Is this an expansion of the airport?..............................................................................................

3.8.1 What plans does the County have for the airport?..............................................................................

3.9 Other Costs to the County...................................................................................................................

3.10 Automated Weather Station..........................................................................................................

3.11 Is the weather so bad that a non-precision approach is useless?..........................

3.11.1 What do pilots do when the weather is below minimums?...............................................................

3.12 Is A GPS Approach the Right Approach?.......................................................................................

3.13 What has been done so far?..............................................................................................................

3.14 What Does the FAA Need from Us?..................................................................................................

3.14.1 Letter asking for the Approach.............................................................................................................

3.14.2 Technical Data Requirements...............................................................................................................

3.14.3 Environmental Impact Study/Assessment............................................................................................

3.14.4 FAA Form 7480-1 “Notice of Landing Area Proposal”...................................................................

3.14.5 What “Strings” are Attached to the GPS Approach?.......................................................................

4. Recommendations...........................................................................................................................................

5. Future Possibility - a Precision Approach?..................................................................................

5.1 What would a precision approach change?.............................................................................

6. Appendix A: Glossary...................................................................................................................................

7. Appendix B: FAA Technical Documents............................................................................................

7.1 “Airport Eligibility Requirements for Establishing an Instrument Approach Procedure (for Airports Not Already Served by a Procedure)”..................................................................................................

7.2 “AC 91-14D - Altimeter Setting Sources”.........................................................................................

7.3 Text From FAR 1 and 1-38 re airspace classifications.........................................................

8. Appendix C: correspondence re technical issues..................................................................

8.1 May 6, 1994 letter from FAA to California airport operators, offering a GPS approach.

8.2 April 26, 1995 letter from CalTrans stating that the County would incur no cost for a GPS approach (see item 3 in the letter)................................................................................................................................

8.3 July 22,1996 letter from FAA Flight Procedures Office stating that the road does not need to be moved and that a 20:1 approach surface is adequate............................................................................

8.4 August 6, 1996 letter from FAA Airports District Office confirming that the road does not have to be moved and that a 20:1 approach surface is adequate............................................................

8.5 October 2, 1996 letter from DPW stating that getting a GPS instrument approach would not change the cost of the airport’s insurance....................................................................................................

8.6 November 5, 1996 letter from El Dorado County Airport Operations Manager stating that their GPS approach has not increased traffic..................................................................................................

8.7 November 8, 1996 letter from the Hollister airport manager stating that their GPS instrument approach has not increased traffic..................................................................................................

8.8 November 8, 1996 letter from Auburn Municipal Airport stating that their GPS approach has not increased traffic.............................................................................................................................................

8.9 November 13, 1996 letter from DPW stating that properly trained private observers may use the County altimeters to give the altimeter setting and they will be covered by the County’s liability insurance........................................................................................................................................................................................

8.10 November 13 letter from Andy Becker (airport supervisor) to DPW stating that he will give the altimeter setting by telephone..............................................................................................................

8.11 January 3, 1997 FAX from Mammoth Lakes Airport stating that their GPS approach has not increased traffic.....................................................................................................................................................................

8.12 January 29, 1997 letter from Barry Rosenberg of the FAA Flight Procedures Office stating that the ALP meets all technical data requirements for the GPS approach and providing sample letters of concurrance........................................................................................................................................................

8.13 February 11, 1997 FAX from El Dorado County Airports giving statistics on Placerville airport.

8.14 February 14, 1997 letter from Auburn Municipal Airport giving statistics on the airport.

8.15 February 26, 1997, FAX from Hollister Airport giving statistics on the airport.

8.16 March 30 FAX from Rialto Airport stating that their NDB approach doesn’t affect noise or traffic and giving statistics on their airport...............................................................................................

8.17 April 2 FAX from Lompoc airport stating that their VOR, NDB and GPS approaches did not increase traffic and giving statistics on their airport.............................................................................

8.18 March 30 FAX from Camarillo airport stating that their VOR approach did not increase traffic, but did increase noise problems due to the flight path of the approach over residences

8.19 March 30 FAX from Rio Vista airport stating that their VOR approach did not increase traffic and did not increase noise, but it did improve safety........................................................................

8.20 March 30 FAX from Monterey airport stating that their ILS approach did not increase traffic (but they also said it was essential to a Part 139 airport)............................................................

8.21 March 30 FAX from Cable airport stating that their VOR approach “obviously leads to a few more flights on bad days”.......................................................................................................................................

9. Appendix D: survey of airport users regarding different instrument approach types

10. Appendix E: historical weather data and analysis.............................................................

11. Appendix F: correspondence with airport neighbors and users...............................

11.1 January 30, 1996 letter from the Fort Bragg - Mendocino Coast Chamber of Commerce, in favor of a GPS approach................................................................................................................................................................

11.2 June 23, 1996 letter from Coast Flyers requesting the GPS approach.......................

11.3 September 24, 1996 letter from Joel Bornstein in favor of airport improvements and the GPS approach.......................................................................................................................................................................................

11.4 October 26, 1996 letter from Peter Heinie in favor of the GPS approach................

11.5 October 31, 1996 letter from Dobie Dolphin opposing a GPS approach and November 11, 1996 answer to her letter from Tim Scully........................................................................................................................

11.6 November 2, 1996 FAX from Jacques Tenzel, M.D. in favor of the GPS approach..

11.7 November 2, 1996 letter from Charlie Eby in favor of the GPS approach...............

11.8 November 3, 1996 letter from Sandy Berrigan opposing the GPS approach and a November 16 answer to her letter from Tim Scully........................................................................................................................

11.9 November 3, 1996 letter from Liz Irwin opposing the GPS approach and raising many questions, and a November 16 answer to her letter from Tim Scully..................................................................

11.10 November 4, 1996 letter from Joanne C. Imperial, M.D. in favor of a GPS approach

11.11 November 6, 1996 email from Vince Taylor in favor of a GPS approach................

11.12 November 13, 1996 letter from Andy Becker in favor of the GPS approach.........

11.13 November 17, 1996 letter from Judith Barry in favor of a GPS approach............

11.14 March 1997 letter from Frank Robinton in favor an instrument approach..

11.15 March 1997 resolution from the Whitesboro Grange in support of the GPS approach

12. Appendix G: Newspaper Articles and Letters to the Editor..........................................

12.1 “Airport Support” by Chris Chandler, Mendocino Beacon, November 22, 1995, Page 1.

12.2 Bad Weather Bites, by Tom Taylor, in The Mendonesian, December 1995 page 31

12.3 Better Use of the Airport, Joel Bornstein, Mendocino Beacon, October 10, letters to the Editor

12.4 Editorial, Mendocino Beacon, October 17,1996, Page 4........................................................

12.5 Noise, instrument landing possibility under discussion, Beacon Staff, Mendocino Beacon, October 17.1996, Page 1..........................................................................................................................................................

12.6 Peace and Quiet, Anne Goncharoff, Mendocino Beacon, October 17(?), 1996, letters to the Editor

12.7 Airport proposals scrutinized; more work ahead, by Neil Boyle, Mendocino Beacon, October 24, 1996, Page 1.........................................................................................................................................................................

12.8 Keep Little River Airport Little, Arlene Lind, Mendocino Beacon, October 31, 1996, letters to the editor.......................................................................................................................................................................................

12.9 Airport Planning Drawing Feedback, by Beacon Staff, Mendocino Beacon, November 7, 1996, page 1

12.10 Two More Airport Meetings, Mendocino Beacon, November 14, 1996, page 3........

12.11 Letter on Noise Abatement Policy, Jack Reichel, Mendocino Beachon, November 14, 1996, Page 4

12.12 Airport group’s noise policy goes to supervisors, Neil Boyle, Mendocino Beacon, November 21, 1996, page 1.....................................................................................................................................................................................

12.13 Oppose Increased Air Traffic, Tom Wodtezki, Mendocino Beacon, December 26, 1996, page 4

12.14 Unfounded Concerns, Tim Scully, Mendocino Beacon, January 9, 1997, page 4..

12.15 In the Public Interest, Joanne Imperial, M.D., Mendocino Beacon, January 16, 1997, page 4

12.16 Airport group continues work on GPS proposal, Neil Boyle, Mendocino Beacon, January 16, 1997, page 1.......................................................................................................................................................................................

12.17 Not in the Public Interest, Jim Wagoner, Mendocino Beacon, January 23, 1997, page 4

12.18 It Could Happen Here, Greg Menken, Mendocino Beacon, January 23, 1997, page 5

12.19 Misinterpreted, Joel Bornstein, Mendocino Beacon, January 30, 1997, Page 4.....

12.20 Airport Group Refining GPS Ideas, Mendocino Beacon, February 13, 1997, Page 1.

12.21 Airport’s future debated, Mendocino Beacon, March 13, 1997, Page 1....................

13. Appendix H: Notes from community meetings re GPS approach and Noise Abatement

13.1 October 20, 1996 meeting.........................................................................................................................

13.1.1 flyer posted in various locations on October 15, advertising the October 20^th meeting............

13.1.2 October 15 email from Dick Ahrens documenting how the meeting was advertised..................

13.1.3 Minutes of October 20, 1996 community meeting.............................................................................

13.2 November 3, 1996 Community Meeting............................................................................................

13.2.1 flyer posted in various locations on October 29, advertising the November 3^rd meeting..........

13.2.2 Email from Dick Ahrens regarding posting of flyers for 11/3 meeting..........................................

13.2.3 Minutes of November 3, 1996 community meeting............................................................................

14. Appendix I: NEXWOS Automated Weather Station.................................................................

15. Appendix J: Maps showing the proposed approach centerlines and approach trapazoids.

16. Appendix K: Draft letter of concurrence and environmental letter..........

16.1 Draft letter of Concurrence...........................................................................................................

16.2 Draft environmental impact letter...........................................................................................

17. Appendix L: Details of what an instrument flight is like..............................................

17.1 Little River to Oakland........................................................................................................................

17.2 Oakland to Little River (assuming a GPS approach)..........................................................

18. Appendix M: A Brief History of the Ad Hoc Airport Advisory Committee............

1. Summary

The Federal Aviation Administration (FAA) is offering, at no cost to the County, to design a navigational procedure for instrument rated aircraft pilots to approach Little River Airport during limited visibility flying conditions by using the Global Positioning System (GPS). This non-precision flying procedure aids the aircraft pilot to approach the airport through clouds on a specific flight path leading to the runway. The GPS approach procedure is not for actually landing the aircraft “blindly”. To complete a landing after using the GPS approach procedure, the pilot must be able to see the airport at a predetermined height and distance from the airport.

A few pilots based at Little River now have the expensive on-board instruments and training to use GPS approach procedures at other airports and would like to have a GPS approach procedure designed for Little River Airport. Several other local pilots have stated that they will buy approved GPS equipment if Little River Airport gets a GPS approach procedure. The Federal Aviation Administration (FAA) is offering to design GPS instrument approaches for most airports in the Unites States. The available historical weather data for the Little River area suggest that such a GPS approach procedure may be useful about 20% of the time, although such estimates are always approximate since the weather varies greatly from year to year.

What concerns do the neighbors of the airport have?

Two community meetings and many Ad Hoc Airport Advisory Committee meetings have been held to discuss the proposed GPS instrument approach and to gain an understanding of community concerns about it. Over 21 articles and letters to the editor have appeared, pro and con in local newspapers about the proposed approach (see Appendix G).

Many non-pilot neighbors of the Little River Airport, wishing to maintain a small rural airport with as little noise disturbance as possible, have expressed concerns that a GPS approach procedure will facilitate more traffic and noise, and become impetus to necessitate further airport improvements and expansion. Neighbors have also asked if the GPS report will be a burden on the County’s tight budget, if it involves installing new equipment or lights at the airport, if there will be new liability concerns, if the approach would require them to top their trees and if zoning changes would be required.

What is this GPS approach?

The Global Positioning System (GPS) is a navigational aid enabling pilots to know where they are and where they are headed in conditions of limited visibility. A GPS approach procedure is a set of instructions published by the FAA which describe a specific flight path for descent toward landing on a particular runway at a specific airport. Such procedures are used when a layer of clouds limits pilot visibility, allowing pilots to use instruments to navigate while descending to an altitude where visibility is clear enough to complete a landing. The GPS approach procedure does not allow landing if the clouds are lower than about 300 to 400 feet from the ground. The GPS approach procedure includes “missed approach” instructions for times when the pilot flying the approach discovers that the clouds are too low to land and must gain altitude and contact Oakland Center for clearance to an alternate destination.

GPS is replacing other means of navigation, such as Loran, for aircraft, ships and many other applications. GPS navigation does not require new equipment on the ground. Aircraft using GPS must have FAA approved GPS receivers installed at the owner’s expense. Pilots must have special training, pass written and flight tests and then must continue to train regularly to legally fly an instrument approach. Their aircraft also must have special equipment, suitable for the approach they plan to fly. This equipment must have its accuracy checked at regular intervals.

What changes will it bring?

The GPS approach will change the FAA’s classification of the airspace around the airport. This only affects pilots, and then only in cloudy weather. It keeps pilots who are not on an instrument flight plan further away from the clouds then the current airspace classification does. It will require instrument rated pilots to file an IFR flight plan before flying through the clouds around Little River.

The airport supervisor will begin giving the altimeter setting when telephoned by the FAA. This will give pilots flying the instrument approach more accurate altitude information. The airport already has the equipment for this.

A GPS approach would improve safety, and would make the airport more accessible in the event of an emergency. All instrument approaches in the United States are being converted to GPS over the next few years.

What isn’t it?

The proposed GPS approach does not involve any expansion of the airport. No new equipment or lights will be installed. There is no cost to the airport or to the County. No land has to be acquired. No new insurance is needed. No zoning changes are needed for the GPS approach - the existing airport height zoning is adequate. The GPS approach does not impose any new regulations to trigger tree topping. The GPS approach has no effect when the weather is good. Pilots land visually in good weather.

There are no plans for airline service or air freight service at Little River airport. The GPS approach is not intended to attract more traffic or commercial users to the airport, it is intended to improve safety for existing users of the airport. The committee surveyed four California airports that already have GPS approaches and has been consistently told that the GPS approach did not increase traffic and slightly reduced noise, while improving safety.

Recommendation

The FAA has all the technical data for designing the approach. All that is needed now is a letter from the County asking for the approach (see details below).

The Ad Hoc Committee recommends that GPS approaches be designed for each landing direction on the runway at Little River. The West approach (called Runway 29) is used normally, due to prevailing winds from the West and Northwest. The East approach (called Runway 11) is used when the wind is strong from the East. The GPS approach will not affect which runway (direction of flight) aircraft use, this is determined by the wind direction.

2. Introduction

This report discusses in detail the FAA’s requirements for obtaining a GPS instrument approach procedure, the costs to the County, the expected impact on the community around the airport and the opinions of users and neighbors of the airport. Many technical terms are used here. See the Glossary in Appendix A for their definitions.

2.1 IFR vs VFR

To understand instrument approaches, it’ll help for you to understand a little about FAA rules.

There are two sets of rules that pilots can fly by. Visual Flight Rules (VFR), can be used by all pilots when the weather is good or clear. VFR means flying visually, being able to see where you are going. Instrument Flight Rules (IFR), allows pilots with the proper training, licensing and equipment to fly through clouds, when they can’t see where they are going. Pilots who lack the training or equipment are not allowed to fly IFR and are required to keep a safe distance from clouds, a distance which varies depending on the type of airspace the pilot is flying in (see section 6.3 in Appendix B for details on this).

You’ve probably heard of “flight plans”. Pilots may fly VFR without a flight plan, wherever they can legally fly at all (except when crossing international borders). Pilots with “instrument ratings” may fly IFR without a flight plan only in Class “G” or “uncontrolled” airspace. Since most airspace is “controlled”, normally pilots flying IFR are flying on an IFR flight plan and are in radio contact with an FAA controller on the ground, who acts as a traffic cop, keeping aircraft flying through the clouds safely separated from each other.

2.2 About Instrument Approach Procedures

The purpose of an instrument approach procedure is to improve the safety of landings when the weather limits pilots flight visibility. Instrument approaches are not needed for takeoffs. They are also not needed for landing in good weather.

Until recently, instrument approach procedures used ground-based navigation aids which are expensive to install and operate. The Little River Airport Master plan (1990) discusses two instrument approach procedures: a non-precision VOR-DME approach procedure which was designed but never published and a possible future ILS precision approach. These both involve the use of ground-based radio transmitters. The VOR-DME non-precision approach had very high minimums, making it of marginal utility. This was due to the great distance between the nearest ground-based VOR-DME station (in the hills between Ukiah and Booneville) and Little River Airport. See the glossary in Appendix A for definitions of VOR, DME, ILS, etc.).

The Global Positioning System (GPS) navigation system was originally developed for military use, but has been declassified and made available to non-military users. Users of GPS have special electronic receivers which pick up and identify signals broadcast from 24 orbiting GPS satellites. These signals contain precisely encoded time signals along with an almanac which tells the receiver the exact position of each satellite. The receiver decodes these signals and computes the receiver’s exact position on the Earth’s surface with reference to longitude and latitude by triangulation. The Global Positioning System is of such accuracy and usefulness to all types of travel that older navigational aids are being phased out.

The FAA has announced plans to replace all ground-based navigation systems with GPS over the next 10 years or so. Thus, the FAA is starting to phase out all other approach and navigation systems and will evolve into a GPS-only structure in the not-too-distant-future. Below is a chart showing the FAA’s approximate schedule, by Calendar Year, for phasing out other forms of navigation. The top seven bars in the chart are existing systems that are being phased out. The bottom two bars are advanced “differential” GPS augmentation systems that are being phased in the supplement basic GPS services.

See the glossary in Appendix A for definitions of the abbreviations in the chart, such as MLS, NDB, etc. The numbers at the top of the chart are calendar years, starting in 1998 and continuing to 2015. This chart was produced from information provided by the FAA and published in the February 1997 issue of Avionics Magazine on page 6.

Instrument approach procedures which provide both horizontal and vertical guidance are called “precision” approaches. Approach procedures which provide only horizontal guidance are called “non-precision”. The proposed GPS approach is a non-precision approach. Precision GPS approaches are not yet available.

Although the accuracy of GPS information can be improved by adding a ground-based "differential" augmentation transmitter (WAAS or LAAS), basic GPS navigation services do not require any ground-based navigation equipment near the airport served by a GPS instrument approach. This expensive equipment is not needed at Little River Airport.

In 1994 the FAA began offering to develop GPS approaches for most US airports. A GPS approach procedure does not require the installation of any new instruments or equipment on the ground, although it does require pilots to buy approved equipment to install in their aircraft.

Airports all over the U.S. already have GPS approaches. Below is a list of some of the California airports which already have GPS approaches.

Alturas Hayward Orland San Andreas

Arcata Jackson Oroville San Francisco

Auburn Lakeport Palo Alto San Jose

Chico Lincoln Petaluma Santa Rosa

Columbia Lodi Pine Mountain Lake So. Lake Tahoe

Concord Marysville Placerville Stockton

Crescent City Monterey Red Bluff Truckee

Davis Napa Redding Ukiah

Eureka Nut Tree Rio Vista Watsonville

Fortuna Oakdale Sacramento Willows

Grass Valley Oakland Salinas Woodland

Pilots must have special training and pass written and in flight tests to get an "instrument rating" which allows them to fly by Instrument Flight Rules (IFR) and use instrument approach procedures. A little over half of all licensed pilots are instrument rated. Their airplanes must be properly equipped with the instruments required for the procedure they want to use. The rules also specify how often the airplane's instruments must have their calibration checked. Instrument rated pilots are also required to have substantial recent (within the last 6 months) experience or training (an “instrument competency check” by an instrument flight instructor) in controlling an aircraft in IFR conditions and in flying instrument approaches.

A GPS approach procedure at Little River Airport would require the FAA to reclassify the airspace immediately surrounding the airport from class “G” Uncontrolled Airspace to Class “E” controlled airspace from 700 feet above the ground to 18,000 feet above sea level. During cloudy weather, only pilots flying by Instrument Flight Rules can be flying through the clouds above Little River Airport. During cloudy weather condition, non-instrument rated pilots must keep a further visual distance from the clouds above Little River Airport than was required with class “G” uncontrolled airspace.

The non-precision GPS approach procedure for Little River airport will require the pilot to be in radio contact with Oakland Center, which coordinates and controls all instrument flights in the area. The pilot will either obtain the Little River Airport altimeter setting from Oakland Center (who can obtain it by telephone from the Little River Airport supervisor), or he will obtain it directly from the Little River Airport supervisor by radio. All airports with instrument approaches must provide the current barometric pressure, or have a nearby reliable source of local barometric pressure. Pilots use this to adjust their altimeters to get accurate altitude information. Most airports provide the local altimeter setting to pilots, on request, by radio as they pass nearby. Some airports have automated weather stations broadcasting barometric pressure, wind speed and temperature on VHF radio.

The GPS instrument approach being made available to the Little River Airport by the FAA is a non-precision approach procedure for aircraft descending safely through clouds to a predetermined point where the destination airport must be in sight, allowing the landing to be completed by Visual Flight Rules. The FAA determines this “missed approach point” when they design the approach procedure. It will be one mile from the runway and probably between 300 and 400 feet above the airport’s elevation. Each GPS approach procedure has “minimums” specifying the minimum ceiling (height of clouds above the ground) and minimum flight visibility (distance the pilot can see) that must exist at the destination airport before a landing can be made. For example, the PLACERVILLE GPS approach procedure for Runway 5 has straight in minimums of 457 feet above ground level (AGL) and one mile visibility. This means that a pilot using this approach is not allowed to descend closer than 457 feet from the ground without having the airport in sight, with at least one mile visibility. If a pilot arrives at the “missed approach point” on an instrument approach and does not have the airport in sight, he or she flies the missed approach procedure, climbing away from the airport.

(This “approach plate” is supplied for illustration and not for navigational use.)

Different instrument approaches have different minimums, depending on many factors including the type of aircraft, terrain, obstructions, the altimeter setting source and the type of navigation equipment used.

3. Issues Surrounding the Proposed GPS Approach

3.1 Increased Traffic and Noise

The most frequently mentioned concerns at the community meetings and in letters regarding the proposed GPS approach were concerns about the procedure increasing traffic and hence noise at Little River. Some citizens of Little River and Albion are worried that the proposed GPS approach would increase traffic at the airport, hence increasing noise pollution. They believe that if the GPS approach allows aircraft to land during poor weather conditions when they previously could not land, that there would be an increase in the number of landings and thus more noise events in an otherwise quiet natural environment.

The users of the airport responded by saying that passing lumber trucks, motorcycles and the sound of a neighbor’s lawn mower or chain saw are as loud or louder than the average airplane.

Further, the pilots say that although the GPS approach may enable a few more landings to be completed than could be completed without the approach, it isn’t landings that make the noise. Attempts at landing can create as much or more noise than a successful landing. Currently, it is common for pilots to fly above the clouds in the neighborhood of the airport, circling to look for a “hole” in the clouds so they can get through the clouds without flying through them to land. Although a pilot may end up leaving the area without landing, the neighborhood around the airport has been subjected to far more noise than a straight-in GPS instrument approach would have produced. A pilot using GPS to fly by Instrument Flight Rules (IFR) can approach the airport at a higher altitude before final descent and flying a direct path to the runway, thus broadcasting less noise to the neighborhood. The straight in approach to Runway 29 is over the least populated area surrounding the airport.

We contacted several small California airports which have already obtained GPS approach procedures. Only a fraction of based aircraft have purchased and installed approved GPS receivers which allow them to use the GPS approach. All of the airports responded by saying that their GPS approaches did not increase traffic. They also stated that safety was improved and noise and noise complaints were slightly reduced. The noise reduction comes from the straight-in flight path of pilots using an instrument approach, in contrast to the longer and lower flight path used when flying low, under the clouds. See Appendix C

November 5, 1996 letter from El Dorado County Airport Operations Manager stating that their GPS approach has not increased traffic.

November 8, 1996 letter from the Hollister airport manager stating that their GPS instrument approach has not increased traffic.

November 8, 1996 letter from Auburn Municipal Airport stating that their GPS approach has not increased traffic.

January 3, 1997 FAX from Mammoth Lakes Airport stating that their GPS approach has not increased traffic.

After looking over these responses, neighbors of the airport asked if these airports are really comparable to Little River. We wrote back to ask 5 more questions:

1) How many operations (takeoffs or landings) does your airport have each year?

2) What percentage are transients? (We have many “transient” tourists in the Summer and the neighbor’s main concern is that tourist traffic might increase.)

3) How many based aircraft do you have and how many have approach approved GPS receivers?

4) Was there community concern about your GPS approach, before you got it?

5) Has the community attitude changed now that you’ve have the GPS approach for a while? How?

In March 1997 we FAXed a survey to over 30 California airports in connection with debates on setting up an official Airport Advisory Committee. The survey also included questions about the impact of instrument approaches, and we received 6 responses from airports with instrument approaches. See Appendix C for copies of the responses.

March 30 FAX from Rialto Airport stating that their NDB approach doesn’t affect noise or traffic - they’ve had it for 20 years and are unaware of any contraversy.

April 2 FAX from Lompoc airport stating that their VOR, NDB and GPS approaches did not increase traffic, they are not sure of the impact on noise and there has been no community concern about their instrument approaches. They noted the improved safety from the approaches.

March 30 FAX from Camarillo airport stating that their VOR approach did not increase traffic, but did increase noise problems due to the flight path of the approach over residences (unlike Little River, the straight in approach is over a residential area).

March 30 FAX from Rio Vista airport stating that their VOR approach did not increase traffic and did not increase noise, but it did improve safety.

March 30 FAX from Monterey airport stating that their ILS approach did not increase traffic (but they also said it was essential to a Part 139 airport). They say the approach is a positive safety factor.

March 30 FAX from Cable airport stating that their VOR approach “obviously leads to a few more flights on bad days”. They’ve had their approach since the early ‘60’s.

The AOPA airport directory has these notes for the airports we surveyed:

Placerville: airport is 3 miles East of the city. Noise abatement: All aircraft, 24 hours, no turns North until 3400’ or clear of city, Runway 23 no turns North of Runway 5 until 3400 MSL. Hours 8am to 5pm Winter, 7am to 7pm Memorial Day through Labor Day.

Auburn: 3 miles North of city. Noise Abatement: make 20 degree left turn after departure on Runway 25 to avoid mobile home park and hospital. Hours 8am to 6pm Summer, 8am to 5pm Winter.

Hollister: 3 miles North of the city. Noise Abatement: (none) Hours: 8am to 5pm.

Mammoth Lakes: 6 miles East of the city. Noise abatement: informal flight operational restrictions, contact airport manager. Hours: 8am to 5pm.

Watsonville: 3 miles NW of city. Noise Abatement: no touch and go Runways 8-27 and Runway 20 from 11pm to 7am. Hours 8am to 5pm daily.

Crescent City: 3 miles NW of city. Noise Abatement: none. Hours: 9am to 5pm, service charge after hours.

Lompoc: 2 miles North of city. Noise Abatement: not published. Hours: 8am to 6pm daily.

Rialto: 3 miles NW of city. Noise Abatement: avoid low flight over residential areas South, West and NorthEast of field. No turns below 2500 MSL on departure, avoid South departure below 2500 MSL.

Camarillo: 3 miles W of city. Noise Abatement: Avoid city. No straight-in approach permitted except VOR 26 approach. All quadrants noise sensitive.

Rio Vista: 3 miles NW of city. Noise Abatement: Runway 25 calm wind (5 knots or less). Noise sensitive North of Runway 32. Avoid overflight of ranch and corrals North of Runway 32. Hours: 8am to 5pm weekdays, request on weekends.

Monterey: 3 miles SE of city. Noise Abatement: On departure no turns passing 900 MSL, remail clear of populated areas. Limit on touch and gos, ground runup and Stage II operations - contact airport manager. Hours: 24.

Cable (Upland): 2 miles NW of city. Noise Abatement: no straight ins or outs, immediate left turn after takeoff from Runway 24. Hours: 7:30am to Sunset.

Little River: 3 Miles SE of city. Noise abatement: no straight ins. Hours 8am to 5pm, closed Tuesdays

See Appendix C for copies of the responses which are summarized below:

Airport name	operations per year	% transient	# based aircraft	approved GPS	residents within 2 miles	type of approach	concern before	attitude after
Placerville	68,000	55%	190	unknown #		GPS	none	no problem
Auburn	20,000	35%	200	3 so far		GPS	none	no problem
Hollister	52,000	35-45%	275	10-15		GPS	none	no problem
Mammoth Lakes	no answer yet					GPS
Watsonville	120,000	40%	330	unknown	25,000	LOC, VOR, NDB, GPS	? (old)	unknown (old)
Crescent City	8,800	17%	31	1	unknown	ILS, VOR, GPS	? (old)	unknown (old)
Lompoc	36,000	50%	60	10% (6)	40,000	VOR, NDB and GPS	no	no problem
Rialto	110,000	20%	205	unknown	4-5,000	NDB, GPS	? (old)	no problem
Camarillo	172,905	8%	640	unknown	30,000	VOR	yes	didn’t increase traffic but did increase noise
Rio Vista	30-35,000	98%	55	few	5000	VOR	no	positive
Monterey	??	??	150	few	“many”	ILS, LOC, NDB, GPS	no	no, safety first
Cable	88,000	5%	350	unknown	50,000	VOR	? (old)	no
Little River	2500-6000	unknown	21	2-3			yes

Some of these airports had instrument approaches which had been in use for many years, and they were not able to compare the traffic and noise before and after. These are marked “? (old)” in the table above. Six of the approaches are of older types (pre-GPS) - most aircraft are equipped to fly these older types of approach. One airport reported increased noise because their instrument approach flight path, unlike the proposed approach at Little River, passes over a dense residential area.

Barry Rosenberg of the FAA said that, in his experience, any kind of instrument approach (not just a GPS approach) usually has little impact, generally less than 10%, on traffic, if the instrument approach is added to a runway already in use for visual approaches.

3.2 Altimeter Settings

An airport with an instrument approach procedure must provide the current altimeter setting by radio to the incoming pilot, or there must be some reliable source of this information very nearby. The proposed method at the Little River Airport is to have the airport supervisor use the instruments already available in the airport office to give the current altimeter setting during business office hours of 8am to 5pm Wednesday through Monday of each week.

Why is the altimeter setting needed?

To fly safely on instruments, a pilot has to not only know where she is, she also has to know how high she is. Just knowing you are near a mountain isn't good enough unless you also know you are high enough to fly over it.

For an approach to a landing on instruments this is even more important - the pilot is deliberately flying down toward the ground while in the clouds and unable to see where she is going. Accurate altitude measurement is critical for safe instrument flight, approach and landing.

An altimeter is a very accurate barometer - it measures air pressure precisely. The higher you are, the more of the earth's atmosphere is below you and the less is above you. This results in lower air pressure. If you know what the sea level air pressure is in your neighborhood, you can measure your height above sea level by using an altimeter.

The problem is that sea level air pressure varies as the weather changes. These changes in pressure can cause errors of many hundreds of feet in the altitude displayed by an altimeter. Most airports provide the local altimeter setting to pilots, on request by radio, as they pass nearby, so they can adjust their altimeters to account for this.

How is the altimeter setting usually supplied?

The normal means of providing the altimeter setting is:

· via the control tower, if there is one

· from an automated weather station

· from the airport supervisor or other qualified observer

· from a nearby airport or official weather station

Regardless of where the altimeter setting comes from, it is delivered to pilots by radio, while they are in the air and are approaching the airport.

The official FAA weather station nearest to Little River is in Ukiah. This is too far away for its altimeter setting to be very useful at Little River. Ukiah is also separated from us by hills, which cause temperature differences and magnify the possible differences in air pressure.

Control towers are established only at busy airports. Ukiah airport, which is far busier than Little River, is too small for a control tower. We do not expect Little River to ever have a control tower.

An automated weather station is the ideal long term solution to having the altimeter setting constantly available by broadcasts over an assigned radio frequency from an electronic machine located at the airport. This equipment, named AWOS, NEXWOS or ASOS, is rather expensive ($25,000 or more), and as yet no source of funding has been identified for Little River (see section 3.10).

The remaining alternative is for the airport supervisor (or some other approved person) to provide the altimeter setting. Little River Airport is already equipped which two aircraft-grade altimeters which are calibrated at regular intervals. These meet the requirements of “AC 91-14D - Altimeter Setting Sources”, the FAA Advisory Circular which describes how altimeters setting are to be obtained. A copy is in Appendix B.

The only remaining requirement is for the airport supervisor to give the altimeter setting when it is needed by a pilot to fly the GPS approach. Several issues were raised regarding this:

· the potential liability to the County

· the cost of adding this duty to the airport supervisor’s job description

· what happens when the airport supervisor isn’t available

3.2.1 Liability

The Mendocino County Risk Management Department determined that the existing insurance policy for the airport already covers the risks associated with an instrument approach and with giving the altimeter setting. See Appendix C:

October 2, 1996 letter from the Department of Public Works (DPW) stating that getting a GPS instrument approach would not change the cost of the airport’s insurance.

November 13, 1996 letter from DPW stating that properly trained private observers may use the County altimeters to give the altimeter setting and they will be covered by the County’s liability insurance.

3.2.2 Cost

The current airport supervisor’s contract ends in July 1997. He has indicated that he is willing to provide the altimeter setting under his current contract, provided that the FAA telephones him to request it. Although this is an unconventional procedure, the FAA Flight Standards office in Oakland and Oakland Center have indicated that it could be done. They can phone the airport supervisor, get the altimeter setting and pass it on by radio to the pilot flying the approach. This method of providing the altimeter setting does not add any cost to the County.

3.2.3 Recommendation for the Future

We recommend that when the airport supervisor’s contract comes up for renewal, that giving the altimeter setting (by radio) directly to pilots flying an instrument approach be added to the list of duties to be accomplished on a time-available basis. This should not significantly affect the contract cost and is the conventional means of providing the altimeter setting.

3.2.4 When the Altimeter Setting is not available

Many airports are only staffed part time. The instrument approaches to such airports carry a note stating that the procedure is not authorized when the altimeter setting is unavailable. See the Alturas approach, below, for an example of this. This approach plate is provided for illustration only, and is not for navigation.

Little River is staffed 6 days a week, from 8am to 5pm. Unless pilots make other arrangements for the getting the altimeter setting, the proposed GPS approach will only be usable during the hours when the airport is staffed, and then only when the airport supervisor is able to provide the altimeter setting. If he is pumping gas or attending to other duties, he will not be able to give the altimeter.

It is sometimes possible for pilots to make private arrangements for getting the altimeter setting, and as long as this is from an approved source, they may fly the approach procedure.

In a January 29, 1997 letter, the FAA suggested that it may be possible to offer alternative (much higher) minimums for the Little River approach by using the Ukiah altimeter setting when the Little River altimeter setting is not available. (See Appendix C).

3.3 FAR 77 Surfaces

Federal Aviation Regulation 77 describes imaginary surfaces surrounding each airport. These are shaped somewhat like a huge football stadium, with sides that slope up as you go farther away from the airport. One of the Airport Land Use Commission's jobs is to make sure that these FAR 77 surfaces are not penetrated by anything (buildings, towers, trees, etc.), because any penetrating object will be a hazard to air navigation.

Little River Airport is already subject to FAR 77. The slope of the FAR 77 approach surfaces is now 20:1, i.e. they rise 1 foot for every 20 feet you travel away from the airport, starting at the airport surface and continuing until 150 feet above the airport's surface. This "approach surface" is aligned with the runway and extends 5000 feet from the end of the runway at a slope of 20:1. Another “transitional” surface slants sideways from the runway at a 7:1 slope.

These FAR 77 surfaces are protected by Mendocino County ordinance 3430, adopted on April 25, 1983.

The proposed GPS approach procedure will not change the FAR 77 surfaces and does not require any change in zoning. Letters in Appendix C from the FAA District Office and the FAA Flight Procedures Office confirm that there will be no FAR 77 changes as a result of obtaining a non-precision GPS approach procedure.

July 22, 1996 letter from FAA Flight Procedures Office stating that the road does not need to be moved and that a 20:1 approach surface is adequate.

August 6, 1996 letter from FAA Airports District Office confirming that the road does not have to be moved and that a 20:1 approach surface is adequate.

3.3.1 Topping or Cutting Trees

Several airport neighbors have expressed concerns that getting a GPS approach might require trees in the neighborhood to be topped or cut.

The short answer is: no it will not. But this deserves further discussion.

As stated earlier, Little River Airport is already subject to FAR 77, which sets height limits for objects around airports. These limits have been enacted into County law by Ordinance 3420, adopted April 25, 1983.

The National Ocean Service surveyed the obstructions near Little River Airport in March 1987 and published the results of their survey in an Obstruction Data Sheet ODS 797 and an Obstruction Chart, OC 797. These show that there are numerous trees which penetrate the FAR 77 surfaces.

The FAA has been aware of these obstructions since the chart was published in 1987. Unless there is a complaint filed, or unless they observe a grave risk to public safety, they leave the enforcement of FAR 77 to local government. They will not require tree topping unless someone files a complaint.

Although it is desirable for safety and to limit the County’s liability in the event of an accident involving an illegal obstruction, it is not mandatory for the offending trees to be topped or cut. The proposed GPS approach will have no effect on this situation.

3.4 Runway Protection Zones (Clear Zones)

See page 22, 52, 79, 83-88 of the Airport Master Plan.

There is a "clear zone" or "runway protection zone" at each end of every runway. The runway protection zones at Little River have already been designed for a non-precision approach such as a GPS approach, although the County does not currently own all of the affected land. The land not owned by the County is adequately controlled by the 1983 zoning ordinance.

3.4.1 land purchases

None Required.

The Airport Master Plan suggests in Chapter 10 that land swaps be done to trade airport land which is South of the runway for the land in the clear zone to the East of the runway. Although such a land swap is not necessary for the GPS approach procedure, it is still a good idea. The FAA encourages all airports to own the land making up their Runway Protection Zones.

3.5 Moving the road

The Albion-Little River Road transects the Little River Airport property, crossing the runway clear zone approximately 100 yards East of Runway 29’s threshold. Aircraft approaching for landing on the commonly used Runway 29 are flying low (between 50 and 100 feet) over any vehicular traffic on Albion-Little River Road. As both the road and the airport are infrequently used in this rural country, seldom are the times when a vehicle is on the road as a landing aircraft passes overhead. Although signs warn drivers that this may happen, when it does occur, the driver may be startled by the sudden appearance of the aircraft. There is no danger unless the aircraft has a failure and crash lands short of Runway 29.

During clear weather pilots approach Little River airport at 1000 feet above ground level (AGL), visually inspect the surrounding airspace for other aircraft and normally fly a “U” shaped pattern around the runway that finally brings the aircraft onto “final” approach in a direct line to Runway 29. Aircraft flying the proposed GPS approach procedure may not have initial visual contact with the airport, they may be flying through clouds on instruments, using Instrument Flight Rules. Aircraft flying the proposed GPS approach will have to break out of the clouds and have the runway environment in sight while still one mile from the airport and at least 300-400 feet above the ground, or else they will be required to fly the published missed approach procedure, climbing away from the airport. Thus, aircraft landing after completing the GPS approach will be able to see any traffic on the road well before they fly over it.

The possibility of moving Albion-Little River Road further East, so as not to be a hazard for a precision landing procedure, is discussed on Page 99 of the Airport Master Plan. Several citizens expressed concern that this road might have to be moved for the proposed GPS approach. We contacted the FAA and have been assured that this is NOT necessary for the proposed non-precision GPS approach. See Appendix C.

July 22,1996 letter from FAA Flight Procedures Office stating that the road does not need to be moved and that a 20:1 approach surface is adequate.

August 6, 1996 letter from FAA Airports District Office confirming that the road does not have to be moved and that a 20:1 approach surface is adequate.

The discussion of possibly moving the road, in the Airport Master Plan, was in connection with the possibility of a precision instrument approach, such as an ILS. With such an approach, an approach surface slope of 34:1 or 50:1 would be required by the FAA, and aircraft could get as close as ½ mile and within 200 feet of the ground before breaking out of the clouds (see section 5.1 for more discussion of this).

3.6 Airspace

There are two kinds of FAA airspace over Little River Airport. The airspace type doesn’t matter during good weather, but it changes the rules pilots must obey when the weather is cloudy.

Little River Airport is currently under FAA class G or uncontrolled airspace extending from ground level up to 5500 feet above mean sea level (MSL). Above 5500 MSL is FAA Class E controlled airspace, which is within radar overage from Oakland Center, which controls all aircraft flying on instrument (IFR) flight plans in Mendocino County. The air traffic controller keeps aircraft from colliding by knowing their locations and keeping each aircraft on an assigned flight path.

In Class G uncontrolled airspace, instrument rated pilots may fly through the clouds at their own risk, without filing a flight plan and without talking to a controller. Pilots flying by visual flight rules (VFR) in class G airspace are required to have a minimum of 1 mile visibility and stay “clear of clouds” below 1200 feet above ground level. VFR pilots may not fly through clouds at any time.

It is normal for the floor of class E controlled airspace to be lower. In most of California it is at either 700 or 1200 feet above the ground. Little River is far from the nearest FAA radar station, and there is no radar coverage below about 5500 feet. Since there is no instrument approach, the FAA has left the floor of controlled airspace at the point where their radar coverage stops.

The FAA prefers to monitor aircraft flying on instrument flight plans by watching them on radar. In areas of no radar coverage, the FAA limits IFR traffic sharply. For example, in the Little River - Ukiah area, they only allow one airplane at a time to either take off or start an approach for landing on an IFR flight plan. While that one aircraft is operating outside radar coverage they will decline clearance for any other aircraft at either airport. This limits IFR takeoffs or landings to a combined maximum of about one every 15 minutes since each takeoff or landing occupies about that large a time slot.

Instrument rated pilots can now take off legally through the clouds from Little River without a clearance as long as the cloud layer is not too thick (less than 5500 feet). Of course, instrument rated pilots may take off through thick layers of clouds as long as they file a flight plan and obtain a clearance (see Appendix L). And all pilots may legally “scud run”, flying low under the a layer of clouds to land at Little River, without an FAA clearance.

Obtaining a GPS instrument approach would lower the floor of Class E controlled airspace to 700 feet above ground level (AGL). This airspace classification does not have anything to do with FAA control of the airport. In Class E airspace, when there is clear visibility, all pilots may fly by visual flight rules. During cloudy condition, non-instrument rated pilots still fly by Visual Flight Rules, but now can only fly in conditions of at least 3 miles visibility and must maintain a minimum clearance from clouds of 500 feet below, 1000 feet above and 2000 feet horizontally.

In Class E airspace, when visibility is limited by clouds or fog, instrument rated pilots fly by Instrument Flight Rules and must file a flight plan with Oakland Center (the local FAA control facility).

The effects of this change will be:

· to limit the total number of instrument operations (combined landings and departures) to an approximate maximum of 4 per hour

· to discourage the current practice of “scud running”

· to protect the airspace used by pilots flying on instruments

3.6.1 Limited number of IFR operations here

The floor of radar coverage in the area from Ukiah to Little River is about 5,500 feet MSL. Oakland Center (the local FAA control facility) treats the whole area as a “one-at-a-time” area for aircraft on instrument flight plans. This means that they only give clearance for one instrument takeoff or one instrument landing at a time at either Ukiah or Little River. While an instrument landing or takeoff (on an IFR flight plan) is in progress at Ukiah, all other aircraft at Ukiah and Little River must wait until the landing is completed or the pilot taking off has climbed high enough to be in radar coverage or reaches VFR conditions. This takes about 15 minutes per operation and limits that maximum number of flight planned IFR operations for Ukiah and Little River to a combined maximum of about four per hour.

3.6.2 Scud Running

Scud running is a slang term used by pilots to connote flight in marginal weather conditions.

Little River is currently under class G (uncontrolled) airspace. The floor of controlled airspace is 5500 feet MSL. This means that pilots may fly below 1200 feet above the ground with visibility as poor as 1 mile and only have to remain “clear of clouds” to be VFR. Instrument rated pilots may fly through the clouds without a clearance. Thus, local pilots commonly engage in “scud running” - they fly low to the ground, under the low clouds, to land at Little River when low clouds are present. These flights produce more noise impact than would be produced by flying an instrument approach.

Lowering the floor of the Class E airspace to allow instrument rated pilots to fly the GPS approach procedure will limit the ability of non-instrument rated pilots to legally fly to and land at Little River Airport during cloudy weather conditions as Visual Flight Rules will be more restrictive in Class E airspace than in the existing Class G airspace.

If the GPS approach procedure is implemented at Little River, controlled Class E airspace will begin at 700 feet AGL. Pilots may not fly lower than 500 feet AGL until they are close to the runway, but this will still leave the airspace between 500 and 700 feet AGL uncontrolled class G airspace, allowing non-instrument rated pilots to fly or scud run as they do now.

3.6.3 Airspace Protection

Once the floor of class “E” controlled airspace in lowered from 5500 feet to 700 feet, pilots will be discouraged from “scud running”. Most will prefer to use the GPS instrument approach instead. This will keep their aircraft high above the ground for more of the approach and will reduce the noise impact. Pilots flying on an IFR clearance will be protected from VFR traffic by remaining in controlled airspace until 700 feet AGL.

We expect the practice of scud running to taper off over a period of time after a GPS approach has been published, as pilots have approach approved GPS receivers installed.

3.7 New Equipment Purchases

None required by the County.

Pilots will need to buy approach approved GPS receivers for their aircraft and have them legally installed and certified. This costs between $6,000 and $10,000. Although this cost is expected to drop a little over time, it probably will not ever be less than $5,000, due to the cost of installation labor.

3.8 Is this an expansion of the airport?

Concerned citizens have asked if this is an expansion of the airport.

No. It will not add any new land, pavement, lighting, or equipment to the airport. It will not change the size of the airport. It is not expected to increase traffic and it is not expected to attract any new commercial activity at the airport.

3.8.1 What plans does the County have for the airport?

Neighbors of the airport have asked what the County’s plans are for the airport. The best statement of this is the Airport Master Plan and the associated Airport Layout Plan. The FAA considers the Airport Layout Plan to be the official plan, but the Airport master Plan has much more supporting detail.

3.9 Other Costs to the County

In recent correspondence regarding the airport’s 10 year Capital Improvement Plan, there was discussion of the possible need for a survey of the airport for the GPS approach, and a $3,000 line item was added to the CIP to account for this.

A January 29, 1997 letter from Barry Rosenberg of the FAA clarifies that no survey is needed. The existing approved Airport Layout Plan already includes the coordinates needed for the approach, from an earlier survey.

3.10 Automated Weather Station

(AWOS see p66-67 of Master Plan)

Although an automated weather station is not required for the GPS approach, users of the airport have been hoping to have one for many years, and having a GPS approach will increase this desire. An automated weather station would also provide benefits to the rest of the community. It would improve the accuracy of weather forecasts for the area, by providing more data to the National Weather Service, and it would make its weather observations available to the public by telephone and VHF radio.

There are several types of automated weather observing stations in use at airports. These are variously called AWOS, ASOS and NEXWOS (a variation of ASOS). Each of them comes in different versions, with different capabilities. Some airports have purchased their own automated weather stations, the FAA has paid for the installation of some and the National Weather Service has funded some. There is no Federal funding in sight at this time for an automated weather station at Little River.

There are several companies who make FAA approved automated weather stations. We contacted AAI Systems Management Incorporated and obtained a price quote on a basic automated weather station which reports temperature, dewpoint, wind and the altimeter setting. It broadcasts these weather data by VHF radio and also can answer the telephone and provide the same information to any caller. In July 1996, the cost of such a basic system was $26,650, not including shipping or site preparation.

It is possible to hire AAI SMI for $3,600 per year to make 4 on-site visits for preventative maintenance and calibration. Unscheduled maintenance visits would cost more. An alternative is to pay $1100 tuition for a week-long factory training school and have someone local trained to handle this maintenance. The required special tools cost $975. The other specialty tools can be rented for use once a year for a brief time. In either case, the cost of repair parts would be additional.

It is possible to upgrade the basic system by adding visibility and cloud height sensors for another $22,260.

See Appendix I for letters from AAI SMI.

3.11 Is the weather so bad that a non-precision approach is useless?

Mr. Campbell asked if the weather is so bad that only a precision approach such as an ILS would be good enough. In other words, is the coastal stratus (low clouds) and fog so close to the ground that a non-precision GPS approach would not be adequate to guide pilots to a landing.

We won’t know the exact “minimums” for the GPS approach until the FAA designs it. But they will probably be in the range around 300 to 450 feet and 1 mile visibility. The best that a simple GPS approach can offer is 250 and 1, but we have enough trees to raise the minimums above that, at least a little.

We looked for historical weather data and found two sources. One is a CDROM with about 2150 observations of ceiling and visibility data, collected over a 3 year period at a Ft. Bragg station about 14 miles from Little River Airport. These data are presented in Appendix 9. They show that when an instrument approach is needed, the vast majority of the time a non-precision approach is adequate. In the early afternoons we have, on average:

· 68% good weather, no approach needed (better than 1500 foot ceiling and 3 miles visibility)

· 22% poor weather, non-precision GPS useful (between 1500/3 and 300/1)

· 7% weather too bad for a non-precision GPS approach (ceiling below 300 feet or visibility less than a mile)

The other source of data is from John Merriman, the manager of Coast Flyers, the FBO at Little River Airport. John has kept informal records by making notations on a calendar, and he said that his records agree with the summary we developed from the CDROM weather data - that a non-precision approach would be useful about 22% of the time and that when the weather was bad enough for an instrument approach to be needed, a non-precision approach would usually be adequate.

There are times, particularly in summer and in the morning, when the fog and clouds are so low that a non-precision approach would not be adequate, but on most days the weather improves in the afternoon.

3.11.1 What do pilots do when the weather is below minimums?

Pilots are required to plan for an alternate destination airport in case the weather is below minimums at their original destination. This alternate airport must have very good current and forecast weather. As a pilot approaches his intended destination, he will normally radio to inquire about the current weather. If the report is very bad, he may divert to his alternate without attempting to fly the instrument approach procedure. If there is no weather reporting service available, or if the weather is reported to be adequate, the pilot will fly the approach.

Instrument approaches are designed with the understanding that pilots will fly them down to the “missed approach point” and may find that the weather is too bad for a safe landing. In this case, pilots are trained to fly a “missed approach” procedure which tells them how to climb safely away from the airport and back into the “enroute” airway system. Then they can proceed to their planned alternate destination.

3.12 Is A GPS Approach the Right Approach?

Mr. Campbell asked if a GPS approach is really what pilots want. He suggested that pilots might prefer an NDB, VOR or VOR-DME approach.

If money were no object, most pilots would prefer to have an ILS approach. However, at a cost of over $500,000, an ILS approach is not possible for Little River. Also, the FAA plans to phase out ILS, VOR, NDB and VOR-DME approaches over the next 10 years, replacing them all with GPS. Given this information, we surveyed 125 airport users and neighbors by mail. There were 17 responses to the survey, all from pilots who agreed strongly that a GPS approach is the best solution for Little River.

See Appendix D for the details of the survey of airport users.

3.13 What has been done so far?

The FAA already has a copy of the approved Airport Layout Plan. Barry Rosenberg of the Los Angeles Flight Procedures office says that this gives them all of the technical data they require. See Appendix C:

January 29, 1997 letter from Barry Rosenberg, Los Angeles Flight Procedures Office, FAA.

3.14 What Does the FAA Need from Us?

3.14.1 Letter asking for the Approach

The following is a direct quote from the FAA’s “elig.doc which is in Appendix B.

The airport owner or operator must submit to our office a signed letter stating that he/she:

1) Concurs with the Instrument Approach Proposal and

2) Concurs with the establishment of controlled airspace (700’ AGL floor) for approximately five miles around the airport, and acknowledges that the political subdivision (city, county, township) is aware and concurs with this airspace establishment.

3) Is aware that approval of an instrument approach procedure may modify the applicable FAR Part 77 imaginary obstruction identification surfaces for the affected runway(s), and that this may require a revision to or an original Airport Layout Plan (ALP). These surfaces are expected to be maintained free of obstructions.

4) Is aware that the 20:1 or 34:1 obstruction clearance slopes (whichever is appropriate), and the Runway Obstacle Free Zones (OFZ) must be kept clear of obstacles in accordance with FAA Advisory Circular (AC) 150/5300-13.

Note that we have letters in hand from the FAA stating that the existing 20:1 approach slope will not change as a result of this procedure. The FAA also provided us with a sample letter of concurrence from Nevada County Airport (see Appendix C, the January 29,1997 letter from Barry Rosenberg).

The letter should state for which runway(s) the approach(s) should be designed, and if an offset final approach course is desired, this should be described. A proposed draft letter of concurrence for Little River is in Appendix K.

3.14.2 Technical Data Requirements

The FAA needs technical data such as runway coordinates, length, etc. Barry Rosenberg of the Los Angeles Flight Procedures office tells us that the current Airport Layout Plan, which he has, satisfies these requirements (see his January 29,1997 letter in Appendix C).

3.14.3 Environmental Impact Study/Assessment

The FAA wants a letter giving our evaluation of any noise impact of the proposed GPS approach, concerning the following topics:

· Are there noise sensitive areas underlying the proposed flight track? If unpopulated or sparsely populated, so state.

· Whether the proposed procedure is intended to increase the number of aircraft, or change the types of aircraft using the airport.

· Has there been any publicizing through media or town or airport meetings concerning the proposed approach procedure, and has there been any public comment?

· Is any public controversy expected concerning the proposed procedure?

In a telephone interview on 1/22/97, Ron Clenney of the FAA Flight Procedures office said that the FAA usually considers less than 500 people per square mile to be sparsely populated, and they normally examine a trapezoid extending by one-half mile on each side of the runway centerline at the runway threshold and extending 1 mile on each side of the runway centerline five miles from the runway threshold. He said that the approach can be offset up to 15 degrees from the runway centerline.

He said that they usually issue a “categorical exclusion” from the need for an environmental impact study for a GPS approach to a runway already in use for visual approaches, because adding a GPS approach generally does not have an impact.

The approach trapazoid is 7.5 square miles in area. To qualify as sparsely populated, the total population in the trapazoid should be less than 3750. This criterion is easily met for both Runway 29 and Runway 11. See the maps in Appendix J.

In his January 29, 1997 letter, Barry Rosenberg supplied a sample letter from Nevada County airport. It shows that we can refer to the environmental (noise) studies that were done for the Airport Master Plan. A suggested draft environmental letter to the FAA for Little River Airport is in Appendix K.

3.14.4 FAA Form 7480-1 “Notice of Landing Area Proposal”

An FAA Form 7480-1 needs to be filled out, giving the FAA notice of Little River Airport’s change of status from VFR to IFR and, if it hasn’t already been done, notifying them of the change in pattern altitude which the noise abatement program brought about.

3.14.5 What “Strings” are Attached to the GPS Approach?

The only “string” is the statement that the County is “aware” that the obstruction clearance slopes and Runway Obstacle Free Zones must be kept clear of obstacles in accordance with FAA Advisory circular AC 150/5300-13. As discussed in 3.3.1, this is not a new requirement and will not lead to the FAA forcing people to top or cut their trees.

4. Recommendations

We recommend that two non-precision GPS approach procedures be requested. A straight-in approach to Runway 29, for normal use, and a straight-in approach to Runway 11 for occasional use during the times when the wind favors Runway 11.

We recommend that the final approach course for the approach to Runway 29 be aligned with the runway centerline and that the missed approach procedure should specify a climbing left turn, for compatibility with our noise abatement procedure.

We recommend that approach trapazoid for the approach to Runway 11 be offset by 15 degrees to the South (making the final approach course 096 degrees) for noise abatement, and that the missed approach procedure should be a climb on runway heading.

5. Future Possibility - a Precision Approach?

Several neighbors of the airport expressed deep concern that the proposed non-precision GPS approach procedure would be the “nose of the camel under the tent” and that soon the whole camel would be inside, i.e., we’d have a precision instrument approach, airline service with frequent flights, new bright lights shining all night, expensive new equipment on the ground, expansion of the airport, etc., all without further community discussion.

This is not the case.

The Airport Master Plan (p72-73) discusses the possibility of a precision instrument approach at some time in the future. To our knowledge, there are no plans for a precision approach at Little River Airport. The only precision approaches currently available are ILS systems which are very expensive (over $500,000). Although precision GPS approaches will become available at some time in the future, these may also require some ground based equipment, depending on the FAA’s final plan for differential GPS “augmentation”.

Obtaining a GPS approach, either non-precision or precision, will not magically cause an airline to want to start serving Little River. No airline is interested in serving Little River now because there is not nearly enough demand for such service and thus it would not be profitable. The previous airline service to Little River was dropped because it did not make money in spite of an air mail subsidy (which is no longer available). The previous airline service used a privately owned NDB instrument approach. It is possible that the coastal community may grow and may someday want either an airline or air freight service.

Although getting a precision instrument approach does not imply that an airline or other commercial user would start flying to Little River, currently the FAA has stated that they will not design a precision approach for an airport unless it has commercial users who justify designing the approach, and the airport authority specifically requests such an approach. We do not have commercial users of the type the FAA currently wants for a precision approach - either an airline or a light freight carrier such as Fed Ex, UPS, etc.

Although the FAA’s requirements may change, and it may someday be possible to get a precision approach without buying new equipment and without having commercial users, we assume that the County will never request such an approach without community discussion. The County has no plans at this time to request a precision approach.

Nevertheless, the Airport Master Plan discusses the possibility of a precision approach because the weather at Little River is bad enough (the clouds are low enough) to require a precision approach about 7% of the time. Naturally, the current users of the airport would like to have a precision approach. But a precision approach can’t be justified, considering the small number of users, if it is expensive.

Prudent stewardship of the airport should include preserving the future possibility of a precision instrument approach, but such an approach should not be implemented without community involvement and a specific request from the County.

5.1 What would a precision approach change?

If a precision approach procedure to Runway 29 were added at some future date, it would require change in the FAR 77 surfaces and corresponding zoning changes in the trapezoid East of the airport, along the approach to runway 29. This would affect the zoning of a few parcels East of the airport, mostly those owned by the Nature Conservancy. See the map in Appendix J.

The Airport Master Plan suggests in Chapter 10 that land swaps be done to trade airport land which is South of the runway for the land in the clear zone to the East of the runway. Although it is possible to protect the clear zone for a precision approach with zoning laws, it may be simpler to own the land in fee simple.

Precision approaches normally include an approach lighting system. Such a lighting system is installed on the ground and extends for about 3000 feet from the end of the runway. The lights would be turned on only when a pilot is flying the instrument approach, just as the runway lights are. The runway lights (like approach lights) are mounted on the ground and are not visible from the ground off the airport. The airport’s rotating beacon is on a tower, operates continuously during hours of darkness and is visible for many miles around. The rotating beacon produces the light which sometimes annoys airport neighbors. This would not change if an approach lighting system were installed. We do not have funding for an approach lighting system and we do not own the land where approach lights would be installed. This land is currently owned by the Nature Conservancy.

The possibility of moving Albion-Little River Road is discussed on Page 99 of the Airport Master Plan, in connection with a possible future ILS precision instrument approach procedure. The road is currently too close to the end of Runway 29 for a precision instrument approach’s height restrictions. If a precision approach were designed, either the road would need to be moved, or a displaced threshold would be required, shortening the useful runway and moving the touchdown zone further from the road.

6. Appendix A: Glossary

300 and 1/2 - instrument weather is commonly expressed as a ceiling and a visibility. The ceiling is the distance from the ground to the base of the clouds (300 feet in this example). The visibility is the flight visibility in miles - 1/2 mile in this case.

AGL - Above Ground Level - the height above the earth (in contrast to MSL or above mean sea level).

ALSF-1 - the standard approach lighting system which consists of a 3000 foot sequence of light bars spaced 100 feet apart, using 200 watt bulbs.

Altimeter Setting - an accurate local barometric pressure value which pilots must set in their altimeters to make them accurately show height above sea level. Barometric pressure drops with increasing height, and an altimeter is just a very accurate barometer which measures this air pressure.

Approach Lights - these are ground-based lights leading up to the approach end of the runway which make it easier to find the runway when the visibility is poor. There are several approach lighting systems, some with steady lighting, others with strobe lights, some with flashing lights in a sequence which leads toward the runway. These lighting systems improve the "minimums" for an instrument approach by lowering the required flight visibility for safely landing from 1 mile to ½ mile. Precision approaches normally include an approach lighting system.

ASOS - Automatic Surface Observing Station - a robot weather observer similar to but better than an AWOS. ASOS are slowly replacing AWOS. An ASOS costs from about $25,000 to $150,000 to buy, depending on its features and costs from $3,000 to $15,000 per year to maintain.

ATC - Air Traffic Control. Aircraft flying on instrument flight plans are in radio contact with air traffic control. ATC issues “clearances” (instructions) which pilots are required to follow.

Augmentation - basic GPS navigation is accurate to several hundred feet. The FAA has plans for augmenting GPS accuracy with “differential” signals from ground based stations. They are considering several plans - some involve a few widely scattered ground stations (Wide Area Augmentation System). Once an augmentation system is in place, GPS accuracy will improve to only a few feet of error and precision GPS approaches will be designed.

AWOS - Automatic Weather Observing Station - a robot weather observer which transmits weather information by radio and also makes it available by telephone. The most common AWOS is an AWOS-3 which provides the altimeter setting, temperature, dewpoint, winds, ceiling and visibility. An AWOS-A only provides the altimeter setting.

Cat I, II and III - A simple ILS is Category I or Cat I. This usually has approach minimums of a 200 foot ceiling and ½ mile visibility. A Category II approach adds an “inner marker” beacon and lowers the minimums for qualified aircraft and pilots. A Category III approach lowers the minimums still further and can permit “blind” landings by properly equipped pilots and aircraft. Category II and III approaches exist at a few major airports and are generally usable only by commercial airlines due to the special equipment and training required for their use.

Differential GPS - GPS navigation is subject to small errors from several sources. It is possible to install a GPS receiver at a known location on the ground and measure these errors (the difference between the known ground position and the position computed from GPS signals). The ground station can broadcast the differences to other GPS users in the neighborhood and their GPS receivers can apply the correction automatically, greatly increasing GPS accuracy. Differential GPS will be used for precision GPS approaches at some time in the future. (See also “augmentation”).

Displaced Threshold - if there is an immovable obstacle too close to the end of an airport’s runway, sometimes the FAA authorizes displacing the threshold of the runway. This makes the part of the runway close to the obstacle unusable for landings except as emergency overrun. It adds markings on the runway which instruct pilots to touch down past the displaced threshold.

FAA - Federal Aviation Administration - this government agency regulates aviation nationally

FAR 77 - the Federal Aviation Regulation covering "Objects affecting navigable airspace". It sets standards for the heights of obstructions such as buildings, towers, trees, etc. in the neighborhood of airports.

FBO - Fixed Base Operator. This is a business, based on the airport, offering services to pilots. An FBO may operate a fight school, a charter service, a maintenance shop, sell fuel or sell pilot supplies.

GPS - Global Positioning System - a navigation system which uses 24 satellites in low Earth orbit. GPS can provide accurate position information anywhere on the Earth. This appears likely to be the dominant navigation system by the year 2000, if not sooner.

IFR - Instrument Flight Rules - aircraft must fly by these rules when the weather is not good enough to fly VFR - by visual flight rules. Only instrument rated pilots are allowed to fly IFR. Instrument flight is done by reference to instruments instead of by looking outside the aircraft. If an instrument flight plan is filed, FAA controllers keep IFR aircraft separated from each other. An instrument flight plan must be filed to fly IFR in controlled airspace.

ILS - Instrument Landing System, consisting of a localizer transmitter which provides precise horizontal guidance to the runway, a glide slope transmitter which provides precise vertical guidance to the runway and one or more marker beacon transmitters which provide confirmation of key locations along the approach path. Requires three or more transmitters and antenna systems on and near the airport. Most ILS systems also have approach lighting systems.

Instrument Approach Procedure - this is a published procedure or set of steps for pilots to follow to safely land at a particular airport, using a particular means of navigation, such as ILS, GPS, NDB, VOR, Loran, etc. The FAA develops and publishes these procedures and flies them once every year to verify that the approach procedure is still safe.

LAAS - Local Area Augmentation System - a ground-based transmitter for differential GPS which provides local corrections for errors in GPS data. Category II and III precision GPS approaches will probably require local augmentation. These will eventually be installed at major airports.

Loran - a navigation system which depends on a few widely scattered low frequency transmitters which are operated by the Coast Guard and which was originally developed for mariners. At one time pilots believed that Loran would replace VOR navigation, but GPS has in turn begun to replace Loran.

MALSR - this consists of seven light bars spaced 200 feet apart and a number of sequenced flashing lights extending the system to a total length of 3000 feet.

Minimums - a instrument approach procedure spells out a set of steps for navigating safely to a landing. Each procedure has "minimums" which specify the lowest permitted ceiling and worst visibility conditions for safely and legally flying the approach procedure. The minimums specify a minimum descent altitude.

Minimum Descent Altitude (MDA)- the lowest altitude an aircraft can descend to without seeing the runway environment clearly. If a pilot descends to MDA and reached the missed approach point without seeing the runway environment, he must execute a “missed approach procedure”, climbing back up to a higher altitude.

MLS - Microwave Landing System - an alternate technology for precision approaches that began being deployed a few years ago. The FAA now plans to abandon MLS in favor of GPS.

NDB - a non-directional beacon transmitter - used commonly for navigation before WW II, subject to interference from weather and not very accurate. Requires a transmitter on the ground, on or near the airport.

Runway 29 - runways are named by their magnetic compass direction divided by 10. Thus your compass will show 290 degrees (WestNorthWest) if you are facing down runway 29. Each physical runway has two names, one for each direction of landing. Little River has 29 and 11. Runway 29 is most commonly in use, due to the prevailing winds.

SSALR - an approach lighting system consisting of seven light bars and eight sequenced flasher lights, all spaced 200 feet apart. The complete system extends 3000 feet from the runway threshold.

SVFR - Special Visual Flight Rules. These allow non-instrument rated pilots to fly with 1 mile visibility and clear of clouds in controlled airspace, but only with a clearance from ATC.

TACAN - this is a military version of VOR-DME navigation

TERPS manual - this is the FAA's bible for developing instrument procedures and is the "United States Standard for Terminal Instrument Procedures".

VFR - Visual Flight Rules. All licensed pilots may fly VFR if the weather is good. VFR flight involves being able to see and avoid other aircraft, and being able to navigate visually.

VOR-DME - a VOR (Very high frequency OmniRange) transmitter provides more accurate directional guidance than an NDB. The VOR system mostly replaced NDBs after WW II. DME (Distance Measuring Equipment) allows the distance from a VOR transmitter to be measured, increasing navigational accuracy. The nearest VOR-DME transmitter to Little River is in the hills above Ukiah, about 22 nautical miles away. The FAA is planning to replace the VOR system with GPS eventually, to stop having to maintain expensive ground equipment.

WAAS - Wide Area Augmentation System - a transmitter (which may be either ground or space-based) which provides error correction for GPS signals over a wide area. WAAS is expected to be adequate to provide Category I precision approaches at most airports, possibly without the requirement for a local augmentation transmitter.

7. Appendix B: FAA Technical Documents

7.1 “Airport Eligibility Requirements for Establishing an Instrument Approach Procedure (for Airports Not Already Served by a Procedure)”

7.2 “AC 91-14D - Altimeter Setting Sources”

7.3 Text From FAR 1 and 1-38 re airspace classifications

Controlled airspace means an airspace of defined dimensions within which air traffic control service is provided to IFR flights and to VFR flights in accordance with the airspace classification.

NOTE: Controlled airspace is a generic term that covers Class A, Class B, Class C, Class D, and Class E airspace.

Class A Airspace (U.S. Positive Control Areas). All operations must be conducted under instrument flight rules (IFR) and are subject to ATC clearances and instructions. ATC separation is provided to all aircraft.

Class B Airspace (U.S. Terminal Control Areas). Operations may be conducted under IFR, special visual flight rules (SVFR), or VFR. However, all aircraft are subject to ATC clearances and instructions. ATC separation is provided to all aircraft.

Class C Airspace (U.S. Airport Radar Service Areas). Operations may be conducted under IFR, SVFR, or VFR; however, all aircraft are subject to ATC clearances and instructions. ATC separation is provided to all aircraft operating under IFR or SVFR and, as necessary, to any aircraft operating under VFR when any aircraft operating under IFR is involved. All VFR operations will be provided with safety alerts and, upon request, conflict resolution instructions.

Class D Airspace (U.S. Control Zones for Airports with Operating Control Towers and Airport Traffic Areas that are not associated with a TCA or an ARSA). Operations may be conducted under IFR, SVFR, or VFR; however, all aircraft are subject to ATC clearances and instructions. ATC separation is provided to aircraft operating under IFR or SVFR only. All traffic will receive safety alerts and, on pilot request, conflict resolution instructions.

Class E Airspace (U.S. General Controlled Airspace), Operations may be conducted under IFR, SVFR, or VFR. ATC separation is provided only to aircraft operating, under IFR and SVFR within a surface area. As far as practical, ATC may provide safety alerts to aircraft operating under VFR.

Class G Airspace (U.S. Uncontrolled Airspace). Operations may be conducted under IFR or VFR. ATC separation is not provided.

FAR 1, Amendment 1-38

Airspace Reclassification

Adopted: November 14, 1991 Effective: September 16, 1993

AIRSPACE CLASSIFICATIONS

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

AIRSPACE Class A Air- CLASS B CLASS C CLASS D CLASS E CLASS G

FEATURES space Airspace Airspace Airspace Airspace Airspace

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Former Airspace Positive Terminal Airport Radar Airport Traf- General Uncontrolled

Equivalent Control Control Service fic Areas Controlled Airspace

Areas Areas Areas and Control Airspace

Zones

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Operations per- IFR IFR and VFR IFR and VFR IFR and VFR IFR and VFR IFR and VFR

mitted

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Entry Pre- ATC clearance ATC clearance ATC clearance ATC clearance ATC Clearance None

requisites for IFR for IFR for IFR

Radio Radio Radio

contact for contact for contact for

all all all IFR

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Minimum Pilot Instrument Private or Student Student Student Student

Qualifications rating student certificate certificate certificate certifi-

certificate cate

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Two-way Radio Yes Yes Yes Yes Yes for IFR NO

communications operations

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

VFR Minimum Not applicable 3 statute 3 Statute 3 statute *3 Statute **1 Statute

Visibility miles miles miles miles mile

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

VFR Minimum Not applicable Clear of 500 feet below, 500 feet *500 feet **500 feet

Distance from clouds 1000 feet below, 1000 below, 1000 below,

Clouds above, and feet above, feet above, 1000 feet

2000 feet and 2000 and 2000 above,

horizontal feet hori- feet hori- and 2000

zontal zontal feet hor-

izontal

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Aircraft All All IFR, SVFR, IFR, SVFR IFR, SVFR None

Separation and runway and runway

operations operations

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Conflict Not applicable Not applicable Between IFR No No No

Resolution and VFR

operations

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Traffic Not applicable Not applicable Yes Workload Workload Workload

Advisories permitting permitting permitting

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Safety Yes Yes Yes Yes Yes Yes

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Different visibility minimum and distance from cloud requirements exist for operations above 10,000 feet

MSL.

** Different visibility minima and distance from cloud requirements exist for night operations, operations

above 10,000 MSL and operations below 1,200 feet AGL.

8. Appendix C: correspondence re technical issues

8.1 May 6, 1994 letter from FAA to California airport operators, offering a GPS approach.

8.2 April 26, 1995 letter from CalTrans stating that the County would incur no cost for a GPS approach (see item 3 in the letter).

8.3 July 22,1996 letter from FAA Flight Procedures Office stating that the road does not need to be moved and that a 20:1 approach surface is adequate.

8.4 August 6, 1996 letter from FAA Airports District Office confirming that the road does not have to be moved and that a 20:1 approach surface is adequate.

8.5 October 2, 1996 letter from DPW stating that getting a GPS instrument approach would not change the cost of the airport’s insurance.

8.6 November 5, 1996 letter from El Dorado County Airport Operations Manager stating that their GPS approach has not increased traffic.

8.7 November 8, 1996 letter from the Hollister airport manager stating that their GPS instrument approach has not increased traffic.

8.8 November 8, 1996 letter from Auburn Municipal Airport stating that their GPS approach has not increased traffic.

8.9 November 13, 1996 letter from DPW stating that properly trained private observers may use the County altimeters to give the altimeter setting and they will be covered by the County’s liability insurance.

8.10 November 13 letter from Andy Becker (airport supervisor) to DPW stating that he will give the altimeter setting by telephone.

8.11 January 3, 1997 FAX from Mammoth Lakes Airport stating that their GPS approach has not increased traffic.

8.12 January 29, 1997 letter from Barry Rosenberg of the FAA Flight Procedures Office stating that the ALP meets all technical data requirements for the GPS approach and providing sample letters of concurrance.

8.13 February 11, 1997 FAX from El Dorado County Airports giving statistics on Placerville airport.

8.14 February 14, 1997 letter from Auburn Municipal Airport giving statistics on the airport.

8.15 February 26, 1997, FAX from Hollister Airport giving statistics on the airport.

8.16 March 30 FAX from Rialto Airport stating that their NDB approach doesn’t affect noise or traffic and giving statistics on their airport.

8.17 April 2 FAX from Lompoc airport stating that their VOR, NDB and GPS approaches did not increase traffic and giving statistics on their airport.

8.18 March 30 FAX from Camarillo airport stating that their VOR approach did not increase traffic, but did increase noise problems due to the flight path of the approach over residences

8.19 March 30 FAX from Rio Vista airport stating that their VOR approach did not increase traffic and did not increase noise, but it did improve safety.

8.20 March 30 FAX from Monterey airport stating that their ILS approach did not increase traffic (but they also said it was essential to a Part 139 airport).

8.21 March 30 FAX from Cable airport stating that their VOR approach “obviously leads to a few more flights on bad days”.

9. Appendix D: survey of airport users regarding different instrument approach types

In the Ad Hoc Committee’s January 7, 1996 report to the Health Welfare, Planning and Transportation Committee, we reported on a survey, conducted by mail in December 1995, of 125 airport users and neighbors. One of the motivations for the survey was a question raised by Budge Campbell. He asked whether the pilots who use Little River really wanted a GPS instrument approach instead of a VOR, NDB, VOR-DME or other form of approach. The survey included a short essay explaining the various types of instrument approach and asked pilots to rate the desirability of each.

The mailing list for the survey was compiled by merging the airport supervisor’s list of airport users with lists of attendees from various airport meetings.

There were 17 responses to the survey, all of them from pilots. Seven of the respondents were Mendocino County residents and three of the ten non-residents said that they own a second home in Mendocino County. Nine of the seventeen responders had instrument ratings. The pilots voted strongly in favor of a GPS approach. The most desired form of approach was a non-precision GPS approach with an approach lighting system (which would improve the visibility minimums from 1 mile to ½ mile). The least desired form of approach was an NDB approach.

The table below presents the data. Each pilot was asked to rank all of the approach types, with the most desirable being 1 and the least being 7. Many pilots only marked some of the approach types, as can be seen from the “number of responses” column. The average rank is the sum of responses for an approach type divided by the number of responses. The normalized rank gives additional weight to the number of responses by dividing the average rank by the number of responses. The smallest normalized numbers are associated with the most desired approach type.

Type of Approach	number of responses	sum of ranks	average rank sum/number	normalized rank (rank/number)
non-precision GPS with approach lights	11	21	1.91	0.17
non-precision GPS	10	20	2.00	0.20
precision GPS	8	14	1.75	0.22
ILS	4	14	3.50	0.88
VOR-DME	6	32	5.33	0.89
Loran	3	12	4.00	1.33
NDB	1	5	5.00	5.00

10. Appendix E: historical weather data and analysis

The table immediately below is raw meteorological data for Little River Airport from a CDROM, “International Station Meteorological Climate Summary, version 2.0 dated June 1992., produced by the Naval Oceanography Command Detachment, Asheville.

POR = period of record, i.e., how many years data are presented.

NO OBS is the number of observations where it is a positive number

-29 means “statistical estimate”

-50 means “Ace Data, computer, derived or substituted from data available 1964”

-72590 indicates that the data were from a nearby station, #72590, which is Ft. Bragg, CA, elevation 752 feet, latitude 39 28N longitude 123 45W, a location on top of Bald Hill. This is about 14 miles from Little River Airport. Note that Little River Airport is at a slightly lower elevation, 572 feet, which may imply that ceilings would be slightly better at Little River than on Bald Hill.

STA NO. 73198 MENDOCINO CO UNITED STATES OF AMERICA LATITUDE 3915N LONGITUDE 12345W ELEVATION(FT) 00572

AREA NUMBER 2

POR NO

PARAMETER DESCRIPTION JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN (YRS) OBS

ABS MAX TMP (F) 76 78 77 78 90 86 77 82 90 84 82 81 90 25 -72590

MEAN MAX TMP (F) 56 57 58 59 62 64 64 64 65 64 61 58 61 25 -72590

MEAN MIN TMP (F) 40 40 41 44 47 49 49 49 49 47 44 42 45 25 -72590

ABS MIN TMP (F) 24 28 29 26 34 39 41 40 38 32 29 27 24 25 -72590

MEAN NO DAYS

TMP = OR GTR 90(F) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10 -72590

MEAN NO DAYS

TMP = OR LES 32(F) 3.0 1.0 1.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.3 1.0 6.6 10 -72590

MEAN NO DAYS

TMP = OR LES 0(F) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3 -72590

MEAN DEW PT TMP (F) 40 41 40 42 46 49 51 51 51 49 45 40 45 3 -72590

MEAN REL HUM (PCT) 76 81 78 81 86 87 87 82 79 82 80 73 81 3 -72590

MEAN PRESS ALT (FT) 398 432 445 441 466 482 478 478 490 453 411 388 447 0 -50

MEAN PRECIP (IN) 7.60 6.54 4.96 2.59 1.52 0.52 0.07 0.08 0.63 2.23 4.72 6.52 38.0 67 -72590

MEAN SNOW FALL (IN) ************ 0.0****** 0.0 0.0 0.0 0.0 0.0 0.0 0.0************ 25 -29

MEAN NO DAYS PRECIP

= OR GTR 0.1 IN 11.3 10.2 7.2 5.7 4.0 1.4 0.4 0.4 1.8 4.0 7.2 10.2 63.8 67 -29

MEAN NO DYS SNOW FALL

= OR GTR 1.5 IN ************ 0.0****** 0.0 0.0 0.0 0.0 0.0 0.0 0.0************ 25 -29

MEAN NO DYS W/OCUR

VSBY LES 1/2 MI 7.0 6.4 6.5 9.0 13.3 14.1 22.0 17.0 21.0 14.0 6.5 3.0 139.8 3 -72590

MEAN NO DYS TSTMS 0.0 0.0 1.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.5 2.0 3 -72590

P FREQ WND SPD

= OR GTR 17 KTS 5.4 8.1 7.1 5.6 3.6 2.4 1.2 1.0 2.2 1.0 2.0 3.4 3.6 3 -72590

P FREQ WND SPD

= OR GTR 28 KTS 0.1 0.3 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 3 -72590

P FREQ LES 5000 FT

A/O LES 5 MI 40.8 38.3 34.5 34.2 56.7 48.6 55.5 36.1 42.6 47.3 36.1 38.6 42.4 3 -72590

P FREQ LES 1500 FT A/O LES 3 MI

FOR 00-02 LST 14.5 26.3 18.8 18.3 42.3 43.4 62.2 26.3 42.2 40.0 25.1 24.7 32.0 3 -72590

03-05 LST 15.7 21.1 19.9 17.2 45.8 47.5 62.0 39.2 37.8 39.8 22.9 21.0 32.5 3 -72590

06-08 LST 21.0 18.7 23.8 19.0 45.2 46.3 63.2 43.0 42.2 37.3 20.1 24.2 33.7 3 -72590

09-11 LST 17.2 14.0 21.1 17.8 41.1 45.7 43.5 29.0 31.7 40.0 21.7 20.0 28.6 3 -72590

12-14 LST 26.3 25.1 18.5 19.4 45.5 50.0 39.1 28.5 25.6 33.3 21.1 20.0 29.4 3 -72590

15-17 LST 21.5 27.1 24.7 19.4 50.6 49.7 48.4 36.6 34.4 36.0 24.4 26.9 33.3 3 -72590

18-20 LST 22.6 27.5 23.1 20.0 57.1 48.8 57.5 39.2 40.0 43.5 25.7 23.1 35.7 3 -72590

21-23 LST 18.8 24.0 15.7 20.6 47.3 38.3 58.4 33.3 44.4 37.1 27.2 26.9 32.7 3 -72590

P FREQ LES 300 FT A/O LES 1 MI

FOR 00-02 LST 2.2 11.7 7.0 9.4 25.6 25.8 55.1 23.1 30.0 18.9 5.6 5.9 18.4 3 -7259

03-05 LST 2.7 7.6 4.8 8.9 32.1 32.9 59.2 29.6 26.7 19.4 4.5 4.8 19.4 3 -72590

06-08 LST 8.1 10.5 5.4 8.4 33.3 35.0 56.2 34.4 28.3 16.2 5.0 3.8 20.4 3 -72590

09-11 LST 4.3 6.4 8.6 8.9 19.6 20.4 23.7 15.1 13.9 12.4 3.3 4.3 11.7 3 -72590

12-14 LST 8.6 4.1 7.1 5.0 7.8 9.9 10.3 8.6 6.1 12.4 3.3 2.7 7.2 3 -72590

15-17 LST 9.1 8.8 7.0 3.3 14.9 13.7 19.4 18.8 16.7 15.6 5.6 5.9 11.6 3 -72590

18-20 LST 8.1 8.8 6.5 8.3 22.6 17.9 47.8 27.4 30.6 17.2 6.7 3.8 17.1 3 -72590

21-23 LST 3.8 8.2 9.7 9.4 24.6 19.8 52.4 23.7 31.1 19.9 6.1 3.8 17.7 3 -72590

MEAN NUMBER OF DAYS

POR NO

PARAMETER DESCRIPTION JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN (YRS) OBS

CIG = GTR 1000 FT AND VSBY = GTR 3 MI

16 LST 26.0 21.6 26.0 25.5 18.3 15.5 17.0 20.0 20.5 20.0 24.0 24.5 258.9 3 -72590

22 LST 26.5 23.1 26.0 25.0 18.3 18.9 13.0 21.0 17.0 20.0 24.5 27.5 260.8 3 -72590

04 LST 29.0 25.5 26.0 26.0 17.7 15.3 11.5 19.0 19.5 20.5 25.5 27.5 263.0 3 -72590

10 LST 26.5 25.0 24.5 26.5 19.9 15.0 18.0 22.0 21.5 18.0 24.5 28.5 269.9 3 -72590

CIG = GTR 2000 FT AND VSBY = GTR 3 MI W/SFC WND LES 10KTS

16 LST 16.5 7.8 10.5 10.5 7.8 7.8 9.0 12.0 15.5 14.5 16.5 15.0 143.4 3 -72590

22 LST 17.5 14.2 17.5 13.0 11.1 12.2 10.5 15.5 13.5 16.0 19.0 16.5 176.5 3 -72590

04 LST 18.5 13.2 16.5 20.0 12.2 12.5 10.5 16.5 17.0 16.5 17.5 17.5 188.4 3 -72590

10 LST 17.5 16.2 17.0 14.0 12.7 11.6 16.5 19.0 18.5 16.0 17.0 19.5 195.5 3 -72590

SFC WND = GTR 17 KTS AND NO PRECIP.

16 LST 2.1 4.1 3.5 3.5 2.2 1.1 0.5 1.5 2.0 0.5 1.7 1.6 24.3 3 -72590

22 LST 1.5 0.0 2.0 0.5 0.6 0.5 1.0 0.0 1.0 0.0 0.0 1.0 8.1 3 -72590

04 LST 2.7 0.5 2.1 0.0 1.2 0.6 0.0 0.0 0.0 0.5 0.5 1.5 9.6 3 -72590

10 LST 1.0 0.5 0.5 1.5 0.6 0.5 0.0 0.0 0.5 0.0 1.5 0.5 7.1 3 -72590

SFC WND 4-10 KTS AND TMP 33-89 DEG F AND NO PRECIP.

16 LST 14.7 13.7 19.8 18.0 20.3 18.9 26.0 20.0 17.0 18.3 17.2 14.0 217.9 3 -72590

22 LST 14.7 13.2 13.2 14.7 17.2 13.6 11.5 12.5 13.0 18.9 12.3 14.7 169.5 3 -72590

04 LST 21.2 11.4 14.4 14.7 14.3 12.7 11.0 13.5 7.0 14.2 16.7 18.3 169.4 3 -72590

10 LST 18.1 16.3 15.7 18.8 16.9 22.2 26.5 23.0 18.0 15.7 11.7 16.5 219.4 3 -72590

SKY COVER LES 3/10 AND VSBY = GTR 3 MI

16 LST ****************************************************************************** 0 0

22 LST ****************************************************************************** 0 0

04 LST ****************************************************************************** 0 0

10 LST ****************************************************************************** 0 0

CIG = GTR 2500 FT AND VSBY = GTR 3 MI

16 LST 21.5 16.7 21.0 22.0 13.8 13.3 16.0 20.0 20.0 18.5 18.5 19.5 220.8 3 -72590

22 LST 18.5 18.6 23.0 22.0 15.5 18.3 12.5 21.0 16.5 18.5 20.5 21.0 225.9 3 -72590

04 LST 22.0 20.6 21.5 23.0 14.4 15.3 11.5 19.0 19.5 17.5 20.5 21.0 225.8 3 -72590

10 LST 22.5 20.6 22.5 21.0 16.6 13.9 18.0 21.5 21.0 16.5 20.0 23.0 237.1 3 -72590

CIG = GTR 6000 FT AND VSBY = GTR 3 MI

16 LST 17.0 13.7 19.0 18.5 12.7 13.3 16.0 20.0 20.0 17.0 17.0 18.0 202.2 3 -72590

22 LST 17.5 17.2 20.0 19.0 13.8 18.3 12.5 21.0 16.5 18.0 19.0 18.5 211.3 3 -72590

04 LST 18.5 17.7 20.5 20.5 12.7 15.3 11.5 19.0 19.5 17.0 19.5 18.5 210.2 3 -72590

10 LST 17.0 17.2 20.5 18.5 14.4 13.3 18.0 21.5 21.0 15.0 19.0 20.0 215.4 3 -72590

CIG = GTR 10000 FT AND VSBY = GTR 3 MI

16 LST 13.0 13.2 18.5 17.0 12.2 12.8 16.0 20.0 20.0 16.0 16.0 13.0 187.7 3 -72590

22 LST 14.5 16.7 19.5 18.5 12.2 18.3 12.5 21.0 16.5 17.5 17.0 17.0 201.2 3 -72590

04 LST 16.5 17.2 19.0 20.0 11.6 15.3 11.5 19.0 19.5 16.5 18.5 17.5 202.1 3 -72590

10 LST 13.0 15.2 18.5 17.0 13.3 13.3 18.0 21.5 21.0 12.0 17.0 16.0 195.8 3 -72590

STA NO. 73198 MENDOCINO CO UNITED STATES OF AMERICA

The tables below are “processed” data. We’ve taken the raw percentage of time the weather is worse than 1500 and 3 (1500 foot ceiling and 3 miles visibility) and subtracted from it the percentage of time the weather is worse than 300 and 1. The difference is labeled “P - GPS”, and is the probability that the weather will fall in the range between 1500/3 and 300/1, the weather when a nonprecision GPS approach would be useful. We’ve also computed the ratio between P-GPS and 300/1.

As in the tables above, the rows are for 3 hour periods in local standard time (lst).

	January	January	January	January	February	February	February	February
	p <1500/3	p <300/1	p - GPS	ratio	p <1500/3	p <300/1	p - GPS	ratio
00-02 lst	14.5	2.2	12.3	5.59	26.3	11.7	14.6	1.25
03-05 lst	15.7	2.7	13	4.81	21.1	7.6	13.5	1.78
06-08 lst	21	8.1	12.9	1.59	18.7	10.5	8.2	0.78
09-11 lst	17.2	4.3	12.9	3.00	14	6.4	7.6	1.19
12-14 lst	26.3	8.6	17.7	2.06	25.1	4.1	21	5.12
15-17 lst	21.5	9.1	12.4	1.36	27.1	8.8	18.3	2.08
18-20 lst	22.6	8.1	14.5	1.79	27.5	8.8	18.7	2.13
21-23 lst	18.8	3.8	15	3.95	24	8.2	15.8	1.93

	March	March	March	March	April	April	April	April
	p <1500/3	p <300/1	p - GPS	ratio	p <1500/3	p <300/1	p - GPS	ratio
00-02 lst	18.8	7	11.8	1.69	18.3	9.4	8.9	0.95
03-05 lst	19.9	4.8	15.1	3.15	17.2	8.9	8.3	0.93
06-08 lst	23.8	5.4	18.4	3.41	19	8.4	10.6	1.26
09-11 lst	21.1	8.6	12.5	1.45	17.8	8.9	8.9	1.00
12-14 lst	18.5	7.1	11.4	1.61	19.4	5	14.4	2.88
15-17 lst	24.7	7	17.7	2.53	19.4	3.3	16.1	4.88
18-20 lst	23.1	6.5	16.6	2.55	20	8.3	11.7	1.41
21-23 lst	15.7	9.7	6	0.62	20.6	9.4	11.2	1.19

May

May

May

May

June

June

June