1. Is There a Plan? What Plan is Possible?

The AMPU proposed alternatives are listed below. The Airport Commission emphasized the merits of vertical guidance presented as Alternative 3 in the AMPU in order to enable landings in poor visibility, but there are many reasons why the required Airport standards for vertical guidance cannot be met. There  is no attempt to specify vertical guidance in Alternative 2 in the AMPU. Drawing 2 of the Airport Layout Plan shows Runway Data, with the following values.

  • Ultimate Runway Design Code continues to be shown as B-I-5000.
  • Approach Surface Slope is changed from 20:1 (visual) to 20:1 (Non-precision).
  • No change in the Approach Minimums of 600 ft Minimum Descent Altitude and 1 mile visibility. 
  • FAR Part 77 Approach Category changes from Visual to Non-precision. 
  • RPZ areas are unchanged. 
  • Drawing 10 shows a glide-path slope of 30:1 and Drawing 12 shows a departure slope of 1:40.

The visual runway is changed to a non-precision runway, but the approach minimums are not changed, but for a non-precision instrument approach runway, TERPS requires different values.    

A cleared primary surface which extends 300ft beyond the end of the runway with a width of 500ft. This would require removing the bike trail and clearing additional conservation land and wetland. ·      

 A surface extending from the width of the wider primary surface at a slope of 20 to 1 for a horizontal distance of 4,000 feet and expanding to 2000ft from the present 1250ft would require the 46 avigation easements avigation easements proposed in the AMPU. The AMPU mentions changes to the 1:7 transitional surface, which may also require easements. 

A major reason for changing to non-precision would seem to be allow in principle straight-in approaches, for the benefit of charter flights, which are primarily Pilatus PC-12 charter turbojets. However the discussion below shows that straight-in cannot be realized without a massive increase in the size of the RPZs. In addition without a control tower straight-in approaches are not a safe practice. 

The Airport Layout Plan states that the Airport will continue to have a Runway Design Code of B-I, which does not meet the design standards for a B-II category planes such as the Pilatus PC-12. The airport design standards  for both Group B-I and Group B-II aircraft can be seen below in AC 150/5300‐13A Tables A7-1 and A7-3 respectively .

2. Danger of Straight-in

Without a control tower Chatham Airport is uncontrolled. Straight-in instrument approaches can start up to 12 miles away, and 30° off center-line, and do not require executing a procedure turn, or joining the pattern. Any plane in the pattern has priority, but a straight-in plane relies on there being no other planes on the approach or taking off towards them.  
Six years ago a PC-12 turbo-jet was witnessed by several people flying straight-in under skydivers in the air. On another occasion 2 planes were also seen flying straight-in towards a plane taking off towards them. It is common practice at Chatham Airport for planes to land and takeoff within minutes of each other in opposing directions. 
Flying straight-in requires radio contact for all planes using the Airport, but there are issues with this. It is estimated that up to 20% of fliers do not always listen to their radios, and the Airport website mentions that Cape clearance can be difficult to reach at the ends of the runway. Surprising as it may seem, there is no FAA requirement to use a radio at a non-towered airport, so that  visual sighting is very important and inconsistent with instrument approaches in poor visibility. 
Flying straight-in at Chatham is hazardous, and charters and air taxis needing it should go to Hyannis, where there is a control tower.

4. AC 150/5300‐13A table 3-4 on the left shows the applicable Runway Design Standard for a visual ≥1 mile visibility with a straight-in approach

The minimum runway length is shown as 3200ft.  Another significant issue is high-lighted in this table.  A non-precision straight-in approach for visibility greater than 1 mile is required to use Runway Design Standards applicable to ≥3/4 mile approach visibility minimum”. These standards are shown in tables  A7-1 and A7-3 from AC 150/5300‐13A shown below. These tables show that planes in design group I as well as design group II require significant increases in RPZ areas from the present 8 acres in order to meet the required standard of 3/4 to <1mile visibility.  Both I and II group s require 49 acres for the Approach RPZs and Group II requires 13.7 for the Departure RPZ.

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5. RPZs

The above standards for straight-in  approaches regardless of whether the aircraft are in Group I or Group II, require Approach RPZs of 49 acres. These would include many more residences than are already included in the present 8 acre RPZs, which is totally unacceptable. They are shown in the map on the left and the one below in red. 

Members of the Airport Commission have been trying to argue that there will be no increase in the areas of the RPZs but they propose straight-in. The FAA standards shown above contradict the Airport Commission. Any approval of straight-in would put many more people in danger and is contrary to FAA standards.

6. Statement by the FAA on Incompatible Land Use in an RPZ
“It is FAA policy to object to incompatible land uses that are proposed for property within the RPZ whether or not the airport owns the land and such objection should be anticipated. In particular when we receive a proposal for an airspace study under Part 157 for the RPZ we will object when that proposal conflicts with an airport planning or design standard or recommendation.”

https://www.hud.gov/sites/documents/AIRPORTDIVISION.PDF

7. Standards not Realizable

  • Vertical Guidance (LPV).
  •  Approach Glide-path Qualification Surface GQS requirement of 30:1. 
  • 1:40 Departure Surface.
  • A 3000ft runway length instead of the required 3200ft. 
  • Straight-in Approaches.
  • Any change to the RPZs. 
  • A 500ft wide primary surface leading  to decimating 4.5 acres of wetlands, and removing 8 acres of trees and the bike-path.
  • Any avigation easements.
  • Waiving any of these standards is unconscionable, since it would decrease the safety margins for everybody on the flightpath and especially in the RPZs.

8. The AMPU Proposals/Plans

Do Nothing

  • No clearing of wetland and trees. 
  • No easements. Move runway thresholds. 
  • Will make airport safer by eliminating turboprops and twin-engine prop planes. 
  • No impact to Cat A, recreational small-plane users. 
  • No cost.

Alternative 1: Maintain Existing Part 77 20:1 Slope Approaches

  • Requires 16 avigation easements 
  • Clears 2.7 acres of wetland. 
  • Clears 3.7 acres of woodland on and off airport property. 
  • Cost would be ~$3M before Town legal costs. 

Alternative 2: Establish a Non-Precision (Straight-in) Instrument Approaches 
  • 22 avigation easements. Many more homes in RPZs.
  • Damages 4.5 acres of wetlands. 
  • Removes 8 acres of trees. 
  • Relocate bike-path, border fence, etc. 
  • Cost would be ~$5M before Town legal costs. 
Alternative 3: Establish a Non-precision (Straight-in) Instrument Approach with Vertical Guidance
  • 46 avigation easements. Over 100 homes in RPZs. 
  •  Damages 4.5 acres of wetlands. 
  •  Removes 8 acres of trees on and off Airport property.
  •  Relocates bike-path, border fence, etc . 
  •  Cost would be at least $10M before Town legal costs

9. AMPU Alternative 2

  •  The current Runway Object Free Area width around the runway is only 250ft instead of 500ft. The current Runway Safety Area is only 240ft long and not 300ft.  The current runway to taxiway center-line separation is 150ft instead of 240ft.  The Runway Protection Zones (RPZs) contain ~10 residences, shops, offices and a State highway, which would be put at greater risk. Even if this alternative was allowed under FAA standards, implementing it would require approval under Wetlands Law and would come at a great environmental cost, (16 acres of trees on both sides of the runway and wetland,removal of the bike path, avigation easements and decreased safety for residents on the flight-path and in the RPZs.