The FAA has updated its guidelines for the design of vertiport facilities where eVTOL aircraft will be able to take off and land. Changes to the FAA document reflect the agency’s desire to harmonize guidance on eVTOL vertiports with its existing heliport design standards—a pivot driven by industry pressure, FAA officials acknowledged during a virtual “industry day” event on January 14.

Two years after the FAA published its initial vertiport design guidance in Engineering Brief (EB) No. 105, the U.S. air safety agency published a revised draft—dubbed EB 105A—to the Federal Register in September and requested feedback from the industry. After garnering more than 500 public comments, the FAA implemented substantial changes and quietly published a final version online on December 27.

For the “industry day” discussion, the FAA brought in its vertiport experts to discuss the latest changes to EB 105A and answer public questions about the updated guidance. During the event, the FAA also shared the results of a series of operational test campaigns the agency has been conducting in partnership with eVTOL manufacturers to gather aircraft performance data pertinent to vertiport design standards.

Perhaps the most significant change to EB 105A is the classification of vertiports as a category of heliport. With this change, the FAA has reframed its vertiport design guidance as a supplement to existing heliport design guidelines, which the agency updated in January 2023 with the publication of Advisory Circular 150/5390-2D. That document made no mention of eVTOL or powered-lift aircraft, for which the FAA had been developing separate vertiport guidelines.

Now the agency has opted to classify vertiports as “a type of heliport that we are optimizing for the needs of powered-lift aircraft and special class rotorcraft with three or more propulsors,” explained Robert Bassey, an engineer with the FAA’s Airports Design and Construction Branch who prepared the engineering brief.

“This distinction is important because our helipad design guide traditionally was written to serve the needs of aircraft with single, dual, or tandem rotors. So this new class of aircraft with three or more propulsors require, at a kind of overarching philosophical level, a different type of infrastructure,” Bassey said. For example, vertiports require charging infrastructure and must be able to handle high-frequency operations with rapid turnaround times between flights, he explained. He added that the reclassification also helps to harmonize the FAA’s vertiport guidelines with the language in the special federal aviation regulation for powered-lift aircraft, which the agency published in October.

“We anticipate this will allow state and local jurisdictions to leverage existing infrastructure requirements with minimal changes” as they navigate zoning and licensing processes for new vertiport facilities, explained Wayne Heibeck, deputy associate administrator for the FAA’s Office of Airports.

Unified Vertical Lift Advisory Circular Coming in 2027

The FAA had intended to develop and publish an advisory circular for vertiports by the end of 2025, just like it did for heliports via AC 150/5390-2D in 2023. However, the agency is now changing that plan. Rather, it now intends to produce a “Unified Vertical Lift Infrastructure Advisory Circular,” which would include standards for both heliport and vertiport design, by June 30, 2027.

“We'll be aligning our standards to move toward a unified vertical lift Advisory Circular based on input from you all within the industry and also from Congress,” John Dermody, director for the FAA's Office of Airport Safety and Standards, said during the industry day discussion. “As we move forward in the next 12 to 18 months, we'll need support from the entire vertical lift industry, including helicopter manufacturers and operators, to help us get to the next chapter of our standards development.”

Other changes to EB 105A pertain to the geometry of takeoff and landing sites, including guidance on lighting and markers. It now determines the appropriate geometry of a landing area by factoring in the diameter of an eVTOL aircraft’s rotor system rather than the entire aircraft body size. This accounts for differences in configurations between various types of multirotor eVTOL aircraft and helicopters.

“In traditional heliport design, the rotor diameter typically incorporates the main rotor's downwash—so that's the turbulent air generated by the rotor blades. It incorporates the landing gear footprint and other parts of the aircraft that may come in contact with the ground or the landing surface, such as the tail rotors or the skids,” Bassey explained. “The guidance …ensures that there’s a large enough buffer to protect against the rotor wash while also accounting for the landing gear and the aircraft's ground footprint.” 

The safety area around an eVTOL takeoff and landing zone “must still incorporate the landing gear or touch points, the downwash from the rotors (but this will be different from helicopters due to having smaller rotors, distributed fans, or tilting rotors), and also incorporate other propulsion units,” Bassey said. “This comprehensive safety zone is crucial in order to account for all potential hazards during takeoff, landing, or ground operations.”

Downwash Caution Areas

The FAA has also added guidance on downwash/outwash caution areas in EB 105A. It recommends vertiport facilities post signs in areas where winds generated by an aircraft could reach or exceed speeds of 34.5 mph—“gale-force” winds that pose a hazard to people, property, and even other aircraft, according to the FAA. 

Remarkably, that windspeed threshold is nowhere near the maximum velocities the FAA recorded in its eVTOL downwash and outwash survey, the results of which were published on December 30. That report notes a maximum downwash speed of 100 mph at a distance of 41 feet from the takeoff and landing zone. At a distance of 100 feet, it reported winds exceeding 60 mph. More research is needed to better understand and predict eVTOL downwash effects, which may differ from that of traditional helicopters and other tiltrotor aircraft, according to a study by the U.K. Civil Aviation Authority. 

While a handful of leading eVTOL manufacturers hope to have their aircraft certified and in service this year, the FAA is still working to collect the aircraft operational data it needs to come up with the performance-based vertiport design standards mandated in last year’s FAA Reauthorization Act. 

To help streamline certification efforts, the FAA Office of Airports and the FAA Aircraft Certification Service have agreed to collaborate on the development of performance-based standards for eVTOL landing accuracy, which directly relates to the size of landing surfaces at vertiports. Over the next 12 months, the Office of Airports will conduct operational tests of helicopters to inform the development of those performance-based standards, and eVTOL makers will have the option to demonstrate a landing accuracy equivalent to helicopters as part of the FAA type certification process, Bassey explained.