By: Rex Alexander, Autonomy Global Ambassador – Infrastructure
Across the United States, a dangerous misconception continues to persist within the vertical flight community that if something is not explicitly regulated, it must therefore be acceptable. While this assumption may have once held some practical value in a less complex regulatory environment, it is increasingly becoming indefensible in today’s legal landscape.
Vertical flight infrastructure (think: heliports and vertiports) exists at the intersection of Federal guidance, state adoption, and local enforcement. This layered regulatory framework creates a web of responsibility that is not always clearly understood. From pilots and Part 135 operators to heliport designers, fire marshals, and municipal authorities, many stakeholders do not fully appreciate the legal and litigation exposure they assume when dealing with vertical flight infrastructure.
A Real-World Warning: The Downwash Injury Case
Unlike traditional airports, heliports and vertiports often exist in densely populated, complex environments, such as hospitals, rooftops, urban centers, and public event centers. When something goes wrong, the question will be: what was the standard of care, and who failed to meet it?
A past incident involving a military helicopter illustrates this principle well. While on approach for a static display at a public event, the helicopter generated sufficient downwash during landing to result in airborne debris that injured a bystander.
In this case, the military provided the local requester with a military form to request military aerial support, which provided specific instructions to the requesting entity for the event. However, those procedures were not followed.
Additionally, the state in which the incident occurred requires proponents, other than EMS and law enforcement, to obtain a temporary aeronautical facility license. This process included a requirement to specify provisions to safeguard the public. Unfortunately, the required form was never completed or submitted.
Yet, downwash hazards are well documented in FAA guidance and literature such as FAA Advisory Circular 90-23G, Aircraft Wake Turbulence. This incident was both foreseeable and preventable, two key elements that establish negligence.
Federal (FAA) As The Floor, Not The Ceiling
At the Federal level, the FAA establishes baseline requirements through Title 14 of the Code of Federal Regulations. Under 14 C.F.R. § 91.3, the pilot in command is directly responsible for the operation of the aircraft and therefore shoulders the largest burden of accountability. Additionally, 14 C.F.R. § 91.13 prohibits careless or reckless operation by the pilot that endangers life or property. For Part 135 operators, 14 C.F.R. § 135.229 requires that each airport or landing area used must be “adequate” for the proposed operation.
Critically, the FAA does not directly define the term “adequate” in its regulations. In the absence of a definition, courts and expert witnesses frequently rely upon FAA Advisory Circulars to establish the applicable standard of care. Such is the case with infrastructure, e.g., FAA Advisory Circular (AC) 150/5390-2D, Heliport Design, and now EB 105A, Vertiport Design. In both documents, the FAA states that, “This AC (EB) does not constitute a regulation, is not mandatory and is not legally binding in its own right.” However, the FAA goes on to say that other federal agencies, states, or other authorities having jurisdiction over the construction of heliports and vertiports have discretion in establishing the extent to which these standards do apply.
Although ACs and EBs are not legally binding, in the case of the Heliport Design AC, and the Vertiport EB, the FAA makes the following statement: “The standards and guidelines contained in this AC (EB) are practices the FAA recommends for establishing an acceptable level of safety, performance, and operation for heliports.” This provides evidence of industry’s best practices, which are routinely used in civil litigation to demonstrate what a reasonable operator or designer should have done. While a deviation from FAA guidance may not constitute a regulatory violation, it may, in fact, constitute negligence under common law principles, which can create significant legal exposure.
At the Federal level, additional obligations arise under 14 C.F.R. Part 157, which requires notice to the FAA for the construction, alteration, or activation of landing areas. Failure to do so may result in civil penalties pursuant to 49 U.S.C. § 46301. Of significant note is how Part 157 defines the term “Airport”. Airport means any airport, heliport, helistop, vertiport, gliderport, seaplane base, ultralight flightpark, manned balloon launching facility, or other aircraft landing or takeoff area. By using the phrase, “or other aircraft landing or takeoff area”, the FAA can, and many courts may, interpret any area a pilot may potentially land or take off from is in fact an “airport.”
States Have Codes and Standards
At the State and often the municipal level, many jurisdictions adopt NFPA 418: Standard for Heliports and Vertiports. Once adopted, these standards carry the force of law. Of particular significance is the statement “The design of the heliport or helistop, including all the aeronautical components, shall be in accordance with FAA AC 150/5390-2D, Heliport Design Advisory Circular, or equivalent criteria.” A similar statement is also made regarding vertiports, vertistops, and Engineering Brief (EB)-105A, Vertiport Design. Through this mechanism, FAA guidance is effectively incorporated by reference into enforceable code.
States frequently also adopt the International Building Code (IBC) and International Fire Code (IFC), further expanding enforceable requirements.
This transformation, from guidance to enforceable regulation, significantly elevates liability exposure. Design and operational elements are no longer discretionary. Noncompliance may constitute both a statutory violation and evidence of negligence per se.
Municipalities Provide The Front Line of Enforcement
At the municipal level, local authorities govern and regulate heliports and vertiports through zoning ordinances, building permits, and fire code enforcement. These approvals carry legal significance.
Courts have recognized that governmental entities may be exposed to liability where approvals are granted without adequate consideration of known safety risks. Municipal exposure is particularly acute in urban environments, where heliports and vertiports interact with buildings, HVAC systems, and public spaces.
Failure to account for known hazards, such as downwash, obstacle clearance, exhaust gas fumes, and public separation distances, can result in shared liability among municipalities, designers, and operators.
So Who Is Liable?
One of the most challenging aspects of vertical flight infrastructure liability is its distributed nature. Potentially liable parties include:
- Pilots
- Operators
- Designers and engineers,
- Property owners
- Municipality authorities
- Inspectors and approving agencies
Courts evaluating these cases typically focus on three elements:
- Foreseeability
- Applicable standard of care
- Deviations from that standard
Where a hazard is known, and guidance exists to mitigate it, failure to act is often sufficient to establish negligence.
AAM and Expanding Risk
As Advanced Air Mobility (AAM) operations expand, these risks will only increase. eVTOL aircraft will introduce increased operational density in urban environments, while regulatory frameworks continue to evolve. This gap between innovation, regulation, and policy creates fertile ground for litigation.
In this environment, compliance must be viewed as a minimum threshold, not a safe harbor. Stakeholders must align with both regulatory requirements and accepted industry practices. Failure to do so exposes all involved parties to significant legal risk.
As the vertical flight industry innovates, it must be ready for accountability. Those who continue to treat infrastructure guidance as optional will increasingly find themselves on the wrong side of litigation. Compliance is not just about safety. It may mean the difference between survivability and extinction.