Forecasting what will fly if runway is moved animates airport debate

The campaign against the plan to shift the Aspen airport runway and loosen a long-standing wingspan limit warns voters that doing so would invite a hoard of privately operated Boeing 737s and other bigger, older and dirtier aircraft.

Data from other airports in the Western U.S. that serve mountain-resort destinations where such planes can land suggests there is relatively little demand for private Boeing 737s that are currently too big for Aspen, with no more than a handful of privately operated flights per year over the past four years at Eagle-Vail and Rifle airports, and fewer than that at others. Variants of the Airbus 319 and 320 were not operated privately in the time frame surveyed by Aspen Journalism and covering five airports. (The other three are at Jackson Hole, Sun Valley and Gunnison.)

On the other hand, the Gulfstream 650, which is a new-generation long-range private jet that was subject to a 2012 Federal Aviation Administration ruling preventing its operation under current conditions at Aspen-Pitkin County Airport (ASE), is in regular use in these markets, which are visited by other luxury private jets with wings too wide to currently land at the local airstrip.

The campaign asking voters to amend Pitkin County’s home-rule charter in order to force a future vote on widening the separation between the runway and the taxiway at ASE, which would lift the wingspan limit to 118 feet from 95 feet, at its heart argues that doing so would accelerate local growth and harm quality of life. The campaign challenges the assertion that loosening the wingspan limit will lead to a reduction in noise and emissions generated by the airport, noting that the county’s aviation demand forecast presented to the Federal Aviation Administration (FAA) as part of an Airport Layout Plan (ALP) proposal, anticipates nearly 30% growth in the number of general aviation (GA) and air taxi flights by 2042.

“Nobody knows or can know whether worse old private planes would add more harm than better new airline or private planes could subtract, so net environmental effects are unknowable and unenforceable,” Amory Lovins, an esteemed scientific mind at the forefront of energy efficiency and decarbonization who teaches at Stanford University and launched the Rocky Mountain Institute, told the Snowmass Village Town Council on Oct 14. 

But proponents of the airport project, which has been in the works for the past dozen years and was subject to the ASE Vision community-input process from 2019-20, say claims that the plan will fuel growth are unfounded, and argue that “modernization” is critical for attracting aircraft that will benefit the community.

“The ‘concern’ in question,” referring to the notion that the county’s airport plan will drive growth in air traffic, noise and pollution, “is more accurately described as ‘speculation without factual basis,’” said Kathleen Wanatowicz, a spokesperson for A Whole Lotta People for a Better Airport, which is in favor of defeating ballot question 200, a citizen-initiated charter amendment, and approving a competing measure, ballot question 1C, which would empower the county to move forward with the plan. “We are talking about the future here, and the community and the county set out goals to build an airport that can accommodate the next generation of aircraft, which we know is cleaner and quieter and more fuel efficient.” 

Those two ballot questions, with the future of the airport hanging in the balance, face voters Tuesday.

Stoking concern 

Citizens Against Bigger Planes, a nonprofit group set up to advocate against changes to the runway, prominently notes on its website that it opposes “the expansion of the ASE airport allowing for bigger planes (mostly privately owned G650s and 737s).”

At an Oct. 4 election forum presented by Aspen Daily News and Aspen Public Radio, Lovins voiced what might be a potent criticism of the airport plan weighing on voters’ minds.

“I’m particularly concerned with the risk that once you open up to big planes, you end up having to accept anything that can fit, and that includes 737s, A-319s, A-320s,” said Lovins, an Old Snowmass resident who since 2022, as the president of the nonprofit Aspen Fly Right, has been calling the county’s runway-shifting plans into question. “There are many, many hundreds of them in private ownership. Many of those owners would love to come here.”

According to data shared by airport consultant Bill Tomcich, who supports the plan to move the runway, there are fewer than 300 Boeing Business Jets (BBJs) and Airbus Corporate Jets (ACJs) currently in service worldwide, including 117 Boeing 737-700s and 800s and 66 Airbus 319s and 320s. Of those 300, fewer than 40 are in operation in the U.S. 

“I maintain that the likelihood of seeing hundreds of hundreds of those aircraft is extremely unlikely,” Tomcich told Snowmass Village Town Council on Oct. 21, adding that Bozeman Yellowstone International Airport in Montana, a group IV airport with more GA traffic than ASE, only sees at most about 15 operations per year of BBJs and ACJs. 

Michael Miracle, director of community engagement for Aspen Skiing Co. parent company Aspen One, which is among the foremost supporters of airfield modification, said the argument by the “big privates” is a “classic red herring” that should cease to be a concern “once people know the facts.” 

“With regard to plane size, particularly on the private side, there is an active disinformation campaign afoot, which is stoking the concern,” Miracle wrote in an email. He also noted that growth trends reflected in the ALP’s aviation demand forecast are an FAA-mandated planning tool, not a community goal or target.

Aspen Journalism looked at the total number of operations — takeoffs or landings — at a sample of airports located near ski areas from January 2021 through August: Jackson Hole Airport (JAC); Friedman Memorial Airport (SUN) in Hailey, Idaho, near Sun Valley; and three Colorado airports, Eagle-Vail (EGE), Rifle (RIL) and Gunnison (GUC). We focused our analysis on all variants of the Boeing 737, the Airbus 319 and 320, the Bombardier Global 7500 and the Gulfstream 650. None of these aircraft are able to currently operate at ASE, but they would be if the wingspan restriction is lifted and all Airport Design Group III aircraft, with a wingspan up to 118 feet, are allowed to land in Aspen. 

According to the FAA data, the number of operations by general-aviation 737s is relatively low at these comparable airports. GA-operated 737-700s at Eagle airport recorded a total of 33 operations between 2021 and 2024, while Jackson Hole airport counted six operations for the 737-700s and 800s during that time frame. Over that four-year period, Rifle airport counted 21 operations for the 737-700s. Sun Valley and Gunnison each had none. 

Our analysis didn’t find any 737s used as air taxis at those airports, and we didn’t find any A-319 or A-320 used for GA or air taxi operations. 

An air taxi is defined as an aircraft with seating limited to 60 and carrying cargo or passengers for compensation, including services provided by private-jet charter and fractional-jet ownership companies. At the Aspen airport, air taxis account for a growing share of operations and together with GA, the two sectors account for about 80% of the annual traffic, with commercial flights closer to 20%.Total operations at Aspen airport have averaged about 50,000 annually from 2021 to 2023. 

Lovins told Aspen Journalism that projecting what might happen in Aspen based on other mountain airports is flawed, maintaining that “big privates” pose an unquantifiable risk. Data from other airports can’t “support a valid inference about how many ‘big private’ planes’ owners or operators would choose to fly to Aspen if allowed to,” he wrote in a comment posted to the Aspen Fly Right website on Friday. “There is no way to estimate or analyze that hypothetical number, which depends not only on activities offered but also on which airplane owners have homes or friends in which places, and which owners particularly value Aspen’s superior characteristics.”

G650 and others

In addition to 737s and A-319s and A-320s, at least two other aircraft with recorded GA operations at comparable airports will become eligible to operate at ASE if the wingspan restriction is lifted: the Bombardier Global 7500 and the Gulfstream 650. In addition, the county’s aviation demand forecast submitted to the FAA adds the Dassault Falcon 10x, a 110-foot-wingspan aircraft that’s still under development and is expected to enter service next year; the Bombardier Global 8000, a model similar to the 7500; and the Gulfstream 700 and 800, which are from the same Gulfstream VI family as the 650. 

The Aspen airport could see 323 operations a year for each of these aircraft by 2042, according to the demand forecast submitted to the feds, along with the Airport Layout Plan that is the key document that lays out the rebuilt-runway plans.

The Gulfstream 650 had the highest numbers of operations in our analysis of the planes that would become eligible for Aspen at comparable airports. The Eagle and Gunnison airports recorded 386 and 34 G650 operations, respectively, between 2021 and 2024. The Jackson Hole and Sun Valley airports recorded 251 and 338 GA operations, respectively, for the G650 between 2021 and 2024.

The G650 is the second-most-used GA aircraft at Rifle airport, with a total of 845 operations between 2021 and 2024. There were also 288 air taxi operations using the G650 at Rifle over that four-year period.

Air taxis at the other airports are also using G650s with a total of 320 operations at Eagle, 48 at Gunnison, 669 at Jackson Hole and 411 at Sun Valley between 2021 and 2024. 

The Bombardier Global 7500, with its 104-foot wingspan, operated 122 times at Eagle, 96 at Sun Valley, 38 at Rifle, 28 at Jackson Hole and eight at Gunnison between 2021 and 2024.

Air taxis have also been using the Global 7500 with 351 operations for the five airports combined over four years, with the highest number of operations recorded at Rifle, with 123, followed by Eagle’s 87. 

The G650 is of particular local note because when the plane was first being developed, it was marketed as fitting within the existing 95-foot wingspan limit, based upon the theory that the “winglets,” which angle upward at the end of the wing, would not count toward the limit. FAA officials threw cold water on that logic in 2012, ruling that winglets count toward wing measurement and thus the G650 would not be ASE compliant.

It has been previously reported that some homeowners in Aspen were among those first G650 customers. Then-airport director John Kinney told The Aspen Times in September 2015 that he was aware of 33 individuals “with Aspen real estate connections [that] had placed orders for the G650s.”

The G650 is a very long range aircraft that can fly as far as 7,000 nautical miles (about 8,100 miles) and seats up to 19 passengers (the same number as the G550 that currently flies to Aspen), but has a wingspan of 100 feet. 

“Globehoppers are far more likely to have [a G650] than a 737 optimized for other segments,” Lovins wrote. “Of course, those around ASE can’t fit the 95-foot wingspan limit, so they’re generally based in Rifle or Eagle, often in heated hangers; owners fly typically into Rifle, then transfer to a smaller jet like a 500/550 for the last 12 minutes.”

The G650 burns about 3% more fuel than the Gulfstream V variants (G500 and G550, currently one of the top private planes at ASE), according to a presentation to the ASE Vision’s Technical Group in 2019 and Aspen Fly Rights’ essay #9 published in May 2023. The G650 is quieter than the two other planes with noise levels 2.9 decibels lower on flyover and 2.5 lower dB on approach than the two other aircraft.

“They’re all good modern aircraft in their class, but they’re far from [proponents’ claims] of ‘the quietest and cleanest private jets ever built,’” Lovins said.

Although the G650 burns more fuel than the G500 or G550 per LTO, current Aspen airport director Dan Bartholomew said it may be more fuel efficient on a trip basis because it has a greater range and doesn’t have to stop as much to refuel than a G500 and, therefore, uses less fuel for an entire trip. 

Lovins said that it may be possible that the G650 burns less fuel on a trip basis, but it depends on the stage lengths, which is the distance an aircraft travels during a specific leg of a journey, and many other details like payload, wind and route.

Although the ASE Vision process established a goal to limit the annual growth in the number of passengers traveling commercially to 0.8%, there is no numerical target for managing the growth of GA flights laid out in the group’s recommendations. However, the “Common Ground” recommendations include implementing a reservation system that favors commercial planes, and lobbying for the ability to charge higher-emitting planes pricier landing fees. 

“With or without an upgraded airport, private aircraft traffic can grow,” said John Bennett, former Aspen mayor and supporter of A Whole Lot of People for A Better Airport.

He added that direct flights from major East Coast feeder markets, which would be possible with the Airbus 220 commercial aircraft identified as likely to serve Aspen if the airfield is redeveloped, could reduce the demand for private jet charters. “If someone could fly first class directly from New York to Aspen — without the unappealing prospect of a two-hour stopover in a crowded Denver airport with long lines — some wealthy travelers would consider saving a few tens of thousands of dollars by flying first class and arriving in the same number of hours.”

What might happen with commercial service?

Although the gap between the opposing two points of view on the airport can feel enormous, there is little disagreement over the assertion that commercial airlines are unlikely to fly 737s into Aspen.

According to a presentation Tomcich put together about 737s, the only two possible 737s that could in theory operate commercially at ASE are the 737-700 and the 737-MAX-7, the latter being even heavier than the 700. 

The 737 is used commercially at Eagle and Jackson Hole airports, where it accounts for about 9% and 11% of the past four-years of commercial operations, respectively. These airports’ commercial operations are mostly served by the E-175 and the A-319. 

But ASE has unique attributes, including the airport’s high elevation, the surrounding mountainous terrain and the density altitude, which refers to thin air at higher elevations, exacerbated by summer temperatures that make air even thinner, decreasing aircraft performance. This makes a heavy aircraft unable to operate here at full load. 

Due to the 737’s heavy weight, old age and ASE’s conditions, Tomcich said that “737-700 with winglets is the only in-service model of the 737-family identified by the Technical Working Group that could be marginally compatible with ASE’s required procedures but would likely be forced to operated with a significant weight penalty [year-round] at ASE.” 

Lovins agreed with Tomcich that it’s unlikely that the airlines will use the 737s at the Aspen airport.

Although both parties agree that it’s unlikely the airlines will use the 737s, the A-319, which emits twice as much greenhouse gas per passenger as the A220-100 and more CO2 per passenger than the CRJ-700, is still a possibility, according to the Airport Vision Committee’s final report. “In short, if we improved our airport to full Group III status, we would open the door to certain planes like the A220-100 that emit less greenhouse gas and other air pollutants, are quieter, and could attain our managed growth goal — but we would also invite larger, more polluting and noisier aircraft like the A-319.”

“It’s one of those ones that, yeah, technically, it could come in here, but would it? I’m not even sure that aircraft is being purchased and manufactured in a significant number anymore. I think we’re seeing this transition to replace the 319 with the A-220-100 or 300 series, newer aircraft. I wouldn’t be overly optimistic about that,” Bartholomew said. 

Tomcich told Aspen Journalism that the original versions of the A-319 perform poorly at high altitude in the summer heat, but there’s a more recent variant, the A-319-115, that is able to operate at similar airports, such as Eagle, but “there simply aren’t enough to meet the demand of these rare high-performance aircraft to ever consider flying them into ASE.”

The Airbus 220-100 is the preferred aircraft mentioned in the Vision process and the ALP. This is said to be the most likely new aircraft to serve the airport and would help the airport to meet the community goals. The A-220-100 emits fewer greenhouse gas emissions per passenger than the CRJ-700 and is quieter. Delta Air Lines is currently the only air carrier serving Aspen that has that aircraft, which has a higher passenger count. “In Delta’s configuration, the A-220-100 seats 109 passengers, which is 33 more than the CRJ-700, but only nine more than the BA-146 that served the Aspen airport for close to 20 years. Its scale fits our community character,” according to A Whole Lot of People for a Better Airport’s website.

Chuck Butler, a representative of the Citizens Against Bigger Planes and Our Airport Our Vote, told Snowmass Village Town Council on Oct. 14 that “[question 200 is] about giving a voice to people on runway decisions and what the future of this valley may look like.” His group believes that redevelopment of the Aspen airport will increase traffic and pollution and worsen the housing crisis, according to their website. 

Proponents of the updated ALP disagree and argue that growth in the valley is driven by the bed base, not the airport’s passenger capacity, and increasing accessibility at ASE would reduce the number of vehicle trips to and from nearby airports, such as Denver, Eagle and Grand Junction.

At a Snowmass council meeting on Oct. 21, when the board declined to take a position on question 1C, Tomcich predicted that the impacts of the runway shift may not be as significant as either side claims.

“There’s a lot of misinformation that continues to be out there. And I also feel like things have been exaggerated — you know on both sides of the debate — in terms of what the likely outcome is going to be,” he said. “I think the notion of lots or hundreds and hundreds of large private aircraft coming in as a result of the upgrading to design category III has been greatly exaggerated. I also think on the pro-airport side that the benefits of some of the cleaner, quieter aircraft have probably been over emphasized as well, because we are not going to see a whole lot of them. I don’t think you’re going to see a whole lot of significant changes to air service moving forward other than the fact that we’ll be in compliance with ADG-III and up to date with the FAA’s modern standards.”

Editor’s note: Aspen Journalism is financially supported by Rob Pew and Susan Taylor; Taylor is the secretary of Aspen Fly Right; Amory Lovins, president of Aspen Fly Right, has also been a contributor, most recently in 2022. Aspen Journalism also receives a grant from the Pitkin County Healthy Community Fund. We are solely responsible for our editorial content.