Larger Planes Driving Airport's Plans For Expansion

Larger aircraft have been coming and going from the Nantucket Memorial Airport in recent years, a trend which has prompted a proposal for a $40 million expansion of its south apron ramp to address an airfield congestion issue.

Airport management held a public hearing via Zoom Thursday evening to introduce the project to the public. It included a 45-minute presentation and Q&A session for neighbors to ask questions and raise any concerns they had with the plan.

"There might be a perception that the need (for this expansion) is more people, more planes, more growth developments, and I'm going to break that down and show that in the summer, the number of operations and visitors is flat or really slowly increasing,” Karberg told the Current in an interview on Wednesday. “That's not what's driving this. Planes are just bigger across all aircraft categories. It is these bigger aircraft that we need to accommodate."

The need for the additional 40,000 square feet of ramp that is planned was in full view this past summer as the airport had to utilize one of its runways to park private aircraft.

“This is a major FAA safety concern,” Karberg said. “They consider that a dual-use pavement for parking and a runway, and that is a safety standard violation.”

Aircraft were also, on occasion, forced to comply with so-called "quick turns" instituted by the airport due to maxed-out parking on the existing ramp. A quick turn is when an airport prepares an arriving aircraft for its departure flight as quickly as possible rather than allowing it to park and sit on its ramp.

“So instead of a plane arriving, sitting on a ramp overnight, and departing the next day with its passenger(s), it arrives and departs, and then it comes back and arrives the next day before departing again,” Karberg said. “It is twice as many operations, twice as much noise.”

"We are not parking to FAA guidelines, which is 15 to 24 points of clearance,” Karberg added. “In many positions, we are interlacing or overlapping wingtips."

Karberg used two examples of older aircraft being phased out by newer, larger models to provide some perspective on the size differences.

The first was the Gulfstream V, which is being replaced by the Gulfstream VII, Karberg said.

The Gulfstream V has a length of 96 feet, a wingspan of 94 feet, and an area of 9,024 square feet. The Gulfstream VII has a length of 110 feet (+15%), a wingspan of 103 feet (+10%), and an area of 11,330 square feet (+26%).

The second example was the well-known Cessna 402 (C402C), which is being replaced with the Pilatus PC12 (PC-12).

The Cessna 402 has a length of 36 feet, a wingspan of 44 feet, and an area of 1,584 square feet. The PC-12 has a length of 47 feet (+31%), a wingspan of 53 feet(+20%), and an area of 3,021 square feet (+91% increase).

“This is a trend we see across all aircraft classes,” Karberg said. “Our project is not based off of future growth trajectories. It is based on what is already here.”

Minimizing congestion on the ramp will also lead to less noise and fuel emissions, Karberg and airport environmental coordinator Cameron Woods said.

Karberg used one example from the summer in which two aircraft were running with full engines for 5-10 minutes because there was not enough room for the planes to get around one another. They had to wait for the airport's crew on the airfield to sort things out before proceeding to where they wanted to go.

“If there's enough space for planes to operate efficiently and clearly in distinct areas, that Global Express is coming in, parking, and shutting down while that CJ3 is just taxiing straight out,” Karberg said.

Karberg also presented a series of charts to illustrate that while there has been growth in the number of general aviation operations, it has predominantly been aircraft coming and going during the offseason and shoulder seasons, not in July and August.

Amongst other topics discussed was the construction of a 15-foot berm, which is being built between Monohansett Road and the airport perimeter. The berm is intended to prevent the noise of aircraft coming and going from the airport from traveling to neighboring properties.

It will be constructed with “a variety of soils” according to the project’s engineer – Richard Lasdin – including piles of the much-discussed PFAS-contaminated soil that already sits on airport property.

When constructing the berm, the ground will be lined with a fabric before the soil is placed on top of it, and then the berm will be topped with a fabric followed by soil and grass being put over it.

One of the attendees, Darla Stuckey, asked Lasdin if this fabric would keep the PFAS from leaching out and spreading to nearby areas. He explained that the fabric will isolate the contaminated soil from precipitation, which it needs to leach out and spread, and will keep PFAS contained.

Adam Ross, who also lives at a neighboring property, expressed his concerns about light pollution and asked about the possible impact this project could have on the night skies.

Lasdin said there are FAA requirements on how to light the pavement and the new Dark Sky bylaw on the island that needed to be followed. The lighting will be shielded on the airfield side of the berm.

“The airport has decided to control these lights so they will only be on when planes are entering and exiting and being prepared for takeoff, otherwise the lights will be turned off,” Lasdin said.

“We did everything we could to keep these (light) poles lower than the berm and managed in a way where they are off most of the time,” Karberg added.

Doug Kepple, who lives on Okorwaw Avenue, brought up the issue of noise. He said he appreciated the berm because an increase in sound from this expansion has been “one of the major fears” he and other neighbors have.

Kepple asked the airport if they would consider extending the berm south about 20 feet and turning it east to cradle the last aircraft with the berm. He said this modification would limit the amount of noise traveling beyond the airfield to neighboring properties and that it could save “about 50 houses an insufferable amount of noise.”

Karberg said it would need to be presented to the airport commission, but both he and Lasdin said they could “definitely” look into it and see if it is a feasible adjustment to the existing plan.

The project will cost approximately $40.8 million, but a significant portion will be covered by grants ($34.2 million) including $28.9 million in FAA discretionary funding. The remaining $6.6 million will be airport funded.

The project is tentatively expected to begin in March, with excavation beginning in April, and paving beginning in May and running into July.