Estimated reading time 11 minutes, 48 seconds.
On Oct. 16, 2021, an Air Methods pilot landing at Tucson Medical Center in Arizona struck the tail of his Airbus AS350 helicopter on the handle of a portable fire extinguisher located next to a perimeter railing at the edge of the rooftop heliport. No one on board the aircraft was injured, but the tail rotor and horizontal stabilizer were substantially damaged.
To the National Transportation Safety Board (NTSB) investigator assigned to the accident, the case seemed open-and-shut: obviously, the pilot hit something he shouldn’t have. Working under the impression that the 100-foot (30-meter) square heliport was approved by the Federal Aviation Administration (FAA) not just for single helicopter operations, but for the multiple helicopters that routinely parked there simultaneously, the investigator found no issues with the helipad, the immediate surrounding physical environment, or Air Methods’ procedures for landing clearances.
In its final report, the NTSB determined the probable cause of the accident to be “the pilot’s failure to maintain clearance from ground equipment during landing,” adding to the long list of accidents the agency has chalked up to simple pilot error.
Yet, for heliport experts including Rex Alexander, president of consulting firm Five-Alpha, the Tucson event was a conspicuous example not only of how inadequate infrastructure can set pilots up to fail, but also of how accident investigators routinely overlook the importance of infrastructure as a causal factor. In Tucson and many other cases, he said, “the total disregard for accepted standards” in heliport design and administration led to an accident that was both predictable and “100 percent preventable.”
Training and education gaps
As Alexander indicated, the Tucson accident wasn’t an isolated occurrence. Last year, he and three co-authors — HeliExperts International owner Raymond Syms, FAA research engineer Cliff Johnson, and Department of Transportation senior air safety investigator John Roberts — published a retrospective analysis of helicopter accidents that have occurred at designated heliports or airports in the United States.
They identified a total of 185 accidents between 1965 and 2013, finding that obstruction hazards and design failures played a significant role in over half of them. Improper size, defined as pilots attempting to operate at a site too small for their aircraft, or multiple aircraft attempting to operate at a site designed for only one helicopter, was identified as a factor in 43 accidents, or 23 percent.
Moreover, because ground damage to helicopter tail or main rotor blades was not required to be reported to the NTSB until 2010, it is likely that additional accidents in which these factors played a role were never captured in the data.
The authors called out a glaring lack of education and training being offered by the FAA or industry to helicopter pilots regarding what constitutes safe, compliant infrastructure and what pilots should do when confronted with bad infrastructure. There is no mention of heliport design standards or safety in the FAA’s Helicopter Flying Handbook or Helicopter Instructor’s Handbook. Although the Aeronautical Information Manual briefly references the acronyms TLOF and FATO, nowhere does it actually define them as a touchdown and liftoff area and a final approach and takeoff area, respectively.
Instead, most of the FAA’s relevant guidance on heliports is contained in an advisory circular, AC 150/5390-2C. The nearly 200-page document contains detailed design criteria for use by heliport developers, but the guidance is only mandatory for projects that have received funding through the federal Airport Improvement Program. Alexander said that’s a very short list, limited to the Indianapolis Downtown Heliport in Indiana, New Orleans Downtown Heliport in Louisiana, and the West 30th Street Heliport in New York City.
Private heliports — including the one at Tucson Medical Center and every other hospital heliport in the U.S. — are not required to follow the standards in the AC unless their state or local municipality requires it. No such requirements were in place when the Tucson Medical Center heliport entered service in 1990, although the city of Tucson does now stipulate compliance with the AC in its zoning criteria.
According to Alexander, who prepared a case study on the Tucson accident, the medical center’s heliport is sized in accordance with the AC’s guidance for a heliport serving a single aircraft. However, whereas the guidance for elevated heliports is to use safety nets at or below the level of the heliport surface to guard against falls (in accordance with Occupational Safety and Health Administration standards), the Tucson Medical Center heliport has a four-foot (1.2-meter) railing around the perimeter. That directly contradicts the AC, which states: “do not use permanent railings or fences since they would be safety hazards during helicopter operations.”
Alexander confirmed that the perimeter railing violates criteria identified in 14 Code of Federal Regulations part 77 for the imaginary surfaces used to define safe approach and departure paths, thus creating an adverse effect on operations. Since the handle of the fire extinguisher that was pushed up against the railing extended even higher, it too was in violation of FAA standards.
Also notable in the Tucson accident is the fact that the pilot landed off-center, rather than on the TLOF indicated by the 40-foot (12-meter) white square with a red cross and white “H” at the center of the heliport, to ensure separation from another Air Methods helicopter — Life Net 2. Although not noted in the investigation report, this was not only common practice but usually necessary, because Life Net 2 is permanently based on the heliport with no separate parking area. Historical satellite imagery from Google Earth shows as many as three helicopters parked at the heliport at any given time.
Yet, the heliport design AC clearly states that its guidance assumes that there will never be more than one helicopter within the FATO and associated safety area. “If there is a need for more than one touchdown and liftoff area at a heliport, locate each TLOF within its own FATO and within its own safety area,” the AC advises.
Looking beyond the pilot
In the Tucson accident, neither the heliport’s design nor its routine use was consistent with FAA standards, facts of which the hospital and Air Methods should have been well aware. Yet, the only one blamed for the accident was the pilot. When contacted by Vertical in regard to the accident, the NTSB doubled down on its probable cause, pointing out that if the pilot had adhered to minimum landing clearances, the accident wouldn’t have happened.
Not every accident investigation is so dismissive of the contributing role played by infrastructure. For example, in March 2015, an Air Methods EC130 B4 crashed while on approach to the St. Louis University Hospital’s rooftop helipad in Missouri, killing the pilot, who had repositioned in high winds to make room for other possible inbound aircraft and was returning to pick up his medical crew. In that case, the NTSB faulted the lack of an adequate approach path to the helipad due to numerous obstructions, as well as the pilot’s decision to land with unfavorable wind conditions.
However, Alexander said that in most of the accidents he has reviewed, investigators simply don’t consider the role played by infrastructure, thereby missing critical data that could help positively impact industry safety. He would like to see more education for investigators on the subject, and infrastructure-specific data elements included in their investigative checklists. Additionally, he would like to see a greater willingness on the part of agencies like the NTSB to hold heliport owners and air carriers accountable for shortcomings that lead to accidents, which would do more to incentivize positive change than always blaming the pilot.
More than a year after the accident at the Tucson Medical Center heliport, the perimeter railing is still in place, and the fire extinguisher handle still extends above the level of the railing. An Air Methods spokesperson told Vertical that the company processed the findings from the investigation through its internal safety management system in line with its “unwavering commitment to safe operations,” but could not give further details. A spokesperson for the medical center was unable to provide comment before this story’s deadline.
Alexander said he has received some pushback from prominent figures in the helicopter industry for his dogged focus on heliport safety, given that helicopters routinely land at unprepared sites that would seem to present much greater risk. But as a former air ambulance pilot himself, he pointed out that pilots are often much more empowered to determine the safety of an offsite landing zone than an established heliport.
“If a pilot is instructed to land at a landing zone at the scene of an accident, pilots are provided the ultimate authority to move a landing zone, and first responders rarely second-guess that decision,” Alexander said. “However, when a pilot says no, I don’t think that your heliport is safe, they get crucified because everybody else is landing there.”
One final irony he noted is that most states require helicopter air ambulance providers to perform annual training for first responders on landing zone safety and setup. There is no similar requirement to train hospitals on how to design and operate a heliport.