By Rex Alexander

An aviation entrepreneur and industry leader with over 40 years of military, general and commercial aviation service, Rex is president of Five-Alpha LLC and infrastructure advisor to the Vertical Flight Society.


The race for AAM infrastructure, industry catches up

Realizing that the U.S. Federal Aviation Administration (FAA) would be unable to complete its official vertiport advisory circular in time to support the first eVTOL operations, the FAA has opted to provide industry with interim guidance on vertiport design through an engineering brief. Around 100 industry stakeholders discussed the FAA’s draft engineering brief on vertiport design at last week’s Heli-Expo event in Dallas, Texas. Rex Alexander, infrastructure adviser to the Vertical Flight Society (VFS) and president of Five-Alpha LLC, chaired the meeting at Heli-Expo. Below is Alexander’s take on the issue.

Gensler Uber Skyport
The U.S. Federal Aviation Administration will host a virtual industry day on March 29 to discuss its engineering brief on vertiport design with industry stakeholders. Uber/Gensler Image

As is frequently the case with rapidly advancing technology, ensuring that well-developed standards are keeping pace with that same technology can oftentimes prove to be a challenge.

In the race to achieve advanced air mobility (AAM) nirvana, industry finds itself in a game of catch-up in creating standards to support AAM infrastructure development. In the U.S., aviation standards fall to the FAA, whose job it is to develop and publish standards for such things as the design and development of airports, heliports, seaplane bases, and yes, vertiports and vertistops.

Generally speaking, the FAA publishes this guidance via the federal aviation regulations (FARs). However, this process can take upward of six years and beyond, and the matrix of legal language created can be so complex that many aviation experts struggle to decipher the regulations clearly. 

To top it off, most regulations reference a never-ending list of other FARs, as well as a confusing multitude of exceptions and exemptions that must be taken into consideration. This is where the FAA’s Advisory Circular (AC) program comes into its own. ACs are designed to be informational documents to inform and provide clear guidance to industry and the general public. While ACs are not regulatory by nature, they oftentimes describe actions or advice that the FAA expects organizations and individuals to implement and follow. 

An excellent example of this is the heliport design advisory circular, FAA AC 150/5390, first published in 1959. However, in the case of vertiports, the FAA has recognized that such an effort will likely not be completed in time to support the first AAM operations. Therefore, to meet the short-term demand of this rapidly advancing industry, the FAA has decided to provide interim guidance via an engineering brief. This then will allow them to keep pace with the ever-changing and ever-advancing eVTOL aircraft technology until a formal advisory circular can be developed.

Mike Hirschberg, executive director of VFS, acknowledged the FAA’s efforts in this endeavor in saying, “We are extremely pleased to see that the FAA recognizes the need to have an interim standard in place for vertiport development while they continue their efforts to create an official vertiport advisory circular.” 

On Feb. 28, the FAA released its Draft Engineering Brief No. 105, Vertiport Design, to the public for comment. In response to this release, three organizations, the Helicopter Association International (HAI), the General Aviation Manufactures Association (GAMA) and VFS, came together during an eight-hour AAM Infrastructure Industry Day workshop for the purposes of garnering industry opinion and feedback. This collaborative effort took place at HAI’s annual Heli-Expo trade show in Dallas, Texas, on March 7 — just one week after the FAA released its vertiport engineering brief to the public.  

“I am pleased that we have been able to pool the resources of the Helicopter Association International with the Vertical Flight Society and the General Aircraft Manufacturers Association in putting together this workshop for the industry,” said James Viola, president and CEO of HAI. “Each organization brings a unique perspective to the table regarding this burgeoning new market known as advance air mobility. For it to achieve future success, this same level of collaboration amongst industry stakeholders will be critical.”

In recent years, the FAA has been progressively working toward a more forward-thinking performance based methodology in its standards development process, in lieu of the more traditional prescriptive based approach. In part, this is so that the U.S. may better align with the International Civil Aviation Organization (ICAO) standards process. However, in the case of AAM eVTOL technology, this approach has run into one undeniable fact — there is just not enough eVTOL aircraft performance data currently available to base good infrastructure decisions on. 

Pete Bunce, president and CEO of GAMA, addressed this by saying, “We commend the FAA office of airports for proactively issuing vertiport design guidance to support the emerging advanced air mobility sector. We, as an industry, are working together to provide comments to the guidance to ensure that state and local departments have the relevant information to make informed infrastructure decisions to support the safety and growth of AAM.”

With this in mind, the FAA understandably has published guidance that is more prescriptive in nature and somewhat more conservative than some in industry may have hoped for. The FAA, however, did include the concept of a “composite aircraft” in the engineering brief in lieu of any historical performance data being available. This is meant to represent a hypothetical eVTOL aircraft which integrates the performance and design characteristics of the nine eVTOL aircraft currently in FAA certification. This composite aircraft is what the FAA encourages vertiport designers to utilize in developing their vertiport design characteristics that are based on the vertiport engineering brief.

Leading last Monday’s industry workshop at Heli-Expo were Jonathan Daniels, unmanned aircraft systems special adviser to HAI and CEO of Praxis Aerospace, Christine DeJong Bernat, director of global innovation and policy for GAMA, and yours truly. Close to 100 stakeholders attended the workshop. This included eVTOL manufacturers, architect and engineering firms, standards developers, and traditional infrastructure designers from not only the U.S. but around the world.

While the effort itself may be less exciting than the event — at its core, it was a line-by-line review of a 48-page government document — the outcome, however, was anything but boring. Those in attendance not only managed to review the engineering brief in its entirety within the allotted time, but produced over 90 comments for FAA consideration. All in all, a stellar performance by everyone involved. 

As for the FAA’s timeline in developing the final vertiport engineering brief, there are two important dates to pay particular attention to. The first of which is March 29, at which time, the FAA will host a virtual industry day for the purpose of directly discussing the engineering brief with industry stakeholders. To participate in this event, individuals will need to register via the FAA’s website.

The second date is April 18, which is the deadline for all public comments to be submitted to the FAA. While anyone may submit comments to the FAA on the vertiport engineering brief, it is highly encouraged that individuals doing so utilize the downloadable comment matrix provided by the FAA on its website to ensure their comments are in fact included. 

The FAA has indicated that they have every intention of publishing a final vertiport engineering brief by June 2022. This document will then provide guidance on vertiport development until such time a formal vertiport advisory circular can be produced, which is tentatively anticipated sometime in 2024.

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  1. nothing about how the pax enter or exit the aircraft or baggage , nothing about how charging coupling is done , how is the vehicle accurately positioned especially if on skids. aborted take off or landing paths and crosswind control with ground effect/wind gradient . is the aircraft going to sit there until next take off ? the Uber scheme required multi level escalators and conveyors with sheltered boarding . turbulence created by the pad itself will be a hazard for upwind approaches. at the point of zero weight wind effects will dominate (hovercraft problem)

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