The FAA has released vertiport design standards to support the introduction of new advanced air mobility (AAM) aircraft into the U.S. airspace system.
On Sept. 26, the agency announced the publication of Engineering Brief (EB) 105, which it described as initial, interim guidance for building vertiport and vertistop sites for electric vertical takeoff and landing (eVTOL) AAM aircraft. The FAA released the document without the benefit of having performance data from any operating eVTOL types, which are still in the development stage and not expected to enter service until 2024 or later.
“At this time, the FAA does not have enough validated VTOL aircraft performance data and necessarily is taking a prescriptive and conservative approach with the recommendations in this EB,” the agency says in the document. “Vertiport guidance is expected to evolve into a performance-based design standard, potentially with aircraft grouped by their performance characteristics.”
Rex Alexander, president of heliport infrastructure consultancy Five-Alpha, says the EB is expected to lead to the release of an FAA advisory circular with firmer guidance, likely in 2024-25.
“The key element that the FAA points to, and I agree with them, is they have no performance data on these eVTOL aircraft to base any decisions on,” Alexander says. “When we look at helicopters and airplanes today, we know what the aerodynamic deficiencies are and design that into our infrastructure [sites] so they are safe and forgiving. Until we have that data, it’s hard to do for vertiports today.”
The 51-page EB 105 document describes physical dimensions for vertiport touchdown and liftoff (TLOF) and final approach and takeoff (FATO) areas; provides guidelines for lighting, markings and visual aids; and introduces initial safety standards and guidelines for aircraft batteries and charging equipment. It also contains requirements for operators seeking to add vertiports to existing commercial airports and existing buildings or structures.
“Our country is stepping into a new era of aviation,” FAA Associate Administrator for Airports Shannetta Griffin says, announcing the release of EB 105. “These vertiport design standards provide the foundation needed to begin safely building infrastructure in this new era.”
Vertiport design guidance from the FAA follows the release in March 2022 of guidance from the European Union Aviation Safety Agency (EASA), entitled “Prototype Specifications for the Design of VFR Vertiports.” In August, U.S.-based standards organization ASTM International released ASTM F3423, an industry consensus “Standard Specification for Vertiport Design,” following a five-year effort.
The FAA Office of Airports released a draft EB 105 earlier this year and held a virtual industry day to discuss the proposed guidance on March 29. Comments on the draft document were due by mid-April.
Alexander, who contributed to both the FAA and ASTM drafting processes, says the resulting standards are closely aligned with some notable differences. For example, the ASTM standard developed by the organization’s F38 unmanned aircraft systems committee covers VTOL aircraft weighing 55 lb. and above; the FAA document calls out aircraft with a maximum takeoff weight up to 12,500 lb.
The FAA engineering brief is less closely aligned with the European standard, Alexander says.
“EASA kind of went out front based on theory versus empirical data,” he explains. “What the FAA published is conservative, which I fully support at this point because we do not know what the capabilities or deficiencies of these aircraft are as of yet. We don’t even have a certified airframe to point to.”
