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Although we can’t yet call them vertiports officially until the U.S. Federal Aviation Administration (FAA) legally defines these landing and take-off facilities, vertiport construction is underway in various locations in the U.S.
DIFCO, for example, initiated construction in mid-April on an “aero-medical” vertiport in Rock Island, Illinois, a partnership project that was announced in early 2021 with Hughes Aerospace and Five Alpha. Also in April, Volatus Infrastructure announced that with community partners, it’s building what it claims will be the first permanent eVTOL vertiport in the Americas at Wittman Regional Airport in Oshkosh, Wisconsin.
Archer Aviation is another firm designing vertiports in the U.S. It’s partnering with Reef, which owns about 4,500 parking garages across the U.S., for construction of vertiports on top of these structures, and has committed to launching urban air mobility (UAM) networks in Los Angeles and Miami.
Just how are these vertiports being designed in the absence of official FAA infrastructure guidelines?
Companies do have the draft engineering brief released by the FAA in March to work with (and the European Union Aviation Safety Agency (EASA) also released its technical vertiport design specs in March).
A final FAA engineering brief is expected in June. However, the formal FAA vertiport advisory circular may not be available until as far in the future as 2024.
This doesn’t mesh well with the timeline for the first eVTOL certifications. Grant Fisk, co-founder of Volatus Infrastructure, said some eVTOL developers are targeting FAA approvals as early as 2023.
Fisk knows this because he, like leaders at other vertiport infrastructure development ventures, is working with the FAA to finish specifications.
“We’re in close contact with the FAA as this finalization proceeds, in regular communication with the FAA at its request,” he said. “I have calls with staff there regularly. We’re also a part of the Advanced Air Mobility Supply Chain Working Group created by the FAA and led by NASA. In this group, we are figuring out how air traffic control will work, the standards for charging eVTOLs, how bright the lights need to be at the landing pads, what pattern of lights, etc. The pads are just about nailed down, but the hardware component for air traffic control on the ground, whether that will be an antennae system or a system using cell towers, will be decided sometime this year.”
Fisk added that Volatus has also sought out industry experts in developing its vertiport designs.
“They’ve ensured we stayed on the right track since day one,” he reported. “We feel confident we’re going to be very accurate in our design to meet FAA regulations.”
Of course, each vertiport is also a regular construction project, he noted, so it must be compliant with local building codes.
Archer is also working with the FAA. Director of business development Andrew Cummins said that his team believes that vertiport regulations will become more flexible over time. “That will enhance our ability to use space efficiently and allow a broad network of sites.”
Once a vertiport is defined by the FAA and its specs made official, state governments and municipalities can get on with developing their ordinances and regulations, said Rex Alexander, president and executive director at Five Alpha.
However, municipalities will also need national fire code and building code standards. “Without these standards in place,” Alexander said, “insurance companies will be extremely reluctant to insure this new infrastructure. This is not only true for accident claims, damages, theft or other incidents, but more importantly for investment protection.”
A look at the brief
Based on what’s in the FAA’s draft engineering brief, the overall geometry of vertiports will be very similar to that of heliports.
“The one area that’s different,” Alexander reported, “at least for the time being and until OEMs provide tangible and validated performance data, is that of the overall dimensions of the site. These dimensions will be slightly larger based on the fact that the FAA has indicated they plan to use the criteria found in Chapter 3, Transport Heliports, of the FAA heliport design advisory circular FAA 150/5390-2C. The FAA’s rational for this increase in size is that of enhanced safety.”
In short, the FAA is going bigger because it has no validated empirical aircraft performance data for which it can base design decisions on. However, should this data become available, these initial dimensions could be reduced.
In the meantime, this larger size isn’t much of a problem in vertiports on the ground, Alexander said, but it will be a problem for rooftop or parking garage vertiports.
“This is primarily due to the fact that the FAA, at least in the current draft engineering brief, is requiring the final approach and take-off [FATO] to be load-bearing,” he explained. “For an eVTOL aircraft with a 50-foot [15-meters] controlling dimension, the FATO needs to be two times this measurement or in this case 100 ft. [30 m]. I am unaware of any heliports in existence in the U.S. that have a 100 ft. X 100 ft. load-bearing surface. This is primarily due to available space and overall cost. The largest rooftop heliports in the U.S. are based on the Sikorsky S-92 which requires a load-bearing touch down and lift off of approximately 60 ft. X 60 ft.”
And along with similar overall geometry, site selection criteria for vertiports are following many of the same safety guidelines used today for heliports, according to Alexander. These include aircraft safety, public safety and noise impacts, obstruction clearances, prevailing winds, aircraft downwash considerations, local zoning regulations and much more.
Advanced Aviation Infrastructure Modernization Act
Another piece of legislation intended to help organizations plan and build AAM infrastructure — the Advanced Aviation Infrastructure Modernization Act (AAIM) — was introduced in the U.S. House of Representatives in December.
Fisk said it may be finished in August and will pass judgement on it then. However, in the meantime, he said “I think it’s amazing that they are ahead of the curve with this, properly ahead of the curve.”
For his part, Alexander sees AAIM as a good first step in the realm of education for policymakers and the general public. “Public acceptance will be driven by public confidence, and public confidence will be driven by public comfort,” he said. “Education will be the key to increasing public comfort.”
Cummins considers the legislation as currently drafted to be positive in that it offers funding to communities for them to plan for the integration of UAM into their regions and also provides funding for the development of vertiport infrastructure.
“If it gets signed into law, it’s a good start,” he said. “It is a relatively small initial investment and it would be positive for the industry if this could be increased over time as this is important transportation infrastructure.”
Determining who is responsible for ongoing regulation of eVTOL vertiport infrastructure also matters. The eVTOL industry wants to avoid issues that might stem from not having one entity such as the FAA regulate all vertiports in the U.S. For example, monitoring the impacts of 5G on helicopter operations is proving to be an issue because not all U.S. heliports are regulated by the FAA.
On the other hand, having the FAA regulate them all may not be possible.
Alexander explained that for the FAA to provide oversight of vertiports (those for private and also public use), that would be a significant change in its allowed oversight and could only be done if the U.S. Congress passes legislation that specifically provides the FAA with that oversight authority.
Additionally, right now under federal regulations, heliports are exempt from the requirements in Part 121 that require operations to be conducted at airports certified under Part 139, and how vertiports will be provided for is yet to be determined.
“The inclusion of a third term (that is, ‘Commercial Use’) could allow for the implementation of some version of Part 139 to be applied to this type of infrastructure,” Alexander said. “But as it stands today, eVTOL aircraft and vertiport operations are expected to be conducted under Part 135 operational regulations.”
This could be a problem, as Part 135.229 allows for a potentially low level of oversight. Alexander points out that it states: “No certificate holder may use any airport unless it is adequate for the proposed operation, considering such items as size, surface, obstructions and lighting.”
“The term ‘adequate’ is a very ambiguous definition,” he said, “which is next to impossible to define and more than likely will not hold up in a court of law. As I’ve said before, public acceptance being driven by public comfort will more than likely demand a much higher level of oversight than just ‘adequate.’”