A question of priorities: Protecting helicopter occupants

In many ways, the fatal Flight For Life accident that occurred in Frisco, Colorado, in July 2015 was not unique.

The hydraulic system design implicated in that crash had already been linked to several previous incidents and accidents in Airbus Helicopters H125s, including one involving Flight For Life operator Air Methods. And many earlier civil helicopter accidents had resulted in catastrophic post-crash fires; in fact, between 1994 and 2013, the National Transportation Safety Board (NTSB) investigated at least 135 helicopter accidents in the United States that resulted in a post-crash fire.

The Bell 429 is one of the helicopter models recently identified by the FAA as having a CRFS fully compliant with the latest standards. Bell Helicopter converted all of its production helicopters to CRFS by 1991, although it didn’t certify the systems in its legacy aircraft to the standards of §27/29.952. Sheldon Cohen Photo

Unlike those previous accidents, however, the Flight For Life crash and its fiery aftermath — which killed pilot Patrick Mahany and seriously injured flight nurses David Rephser and Matthew Bowe — was dramatically captured on surveillance video. Broadcast in an investigative series by KUSA 9NEWS reporter Chris Vanderveen, the horrific footage forced the civil helicopter industry to confront the consequences of decades of relative indifference to crash safety.

The Federal Aviation Administration (FAA) had adopted tough new fuel system crash resistance standards in 1994. But because the standards did not apply to rotorcraft with type certificates approved before those dates, many new helicopters, including the Flight For Life H125, continued to be built with fuel systems that were dangerously susceptible to post-crash fires.

Less visibly but no less significantly, many new-production helicopters were also exempt from the dynamic crashworthiness standards that the FAA had adopted in 1989. According to an FAA analysis of helicopter accident data from 2008 to 2013, even in accidents in which a post-crash fire was present, blunt force trauma accounted for 80 percent of fatalities.

In the aftermath of the Flight For Life crash, many air medical operators voluntarily committed to installing crash-resistant fuel systems (CRFS) in all new helicopters, and equipping current aircraft with CRFS as retrofit kits become available. Patrick Mahany’s widow, Karen Mahany, has become an outspoken advocate for helicopter crash safety, helping to raise awareness of the issue with lawmakers and the general public.

Meanwhile, the FAA convened a Rotorcraft Occupant Protection Working Group (ROPWG) to study the feasibility of incorporating existing occupant protection standards on, first, newly manufactured helicopters, and then existing rotorcraft. Representing a diverse cross-section of the helicopter industry, the group has already completed a cost-benefit analysis for the former task, and is scheduled to deliver specific recommendations for newly manufactured helicopters to the FAA’s Aviation Rulemaking Advisory Committee (ARAC) this January.

As a recently certified helicopter, the Robinson R66 Turbine has a CRFS fully compliant with §27.952. Robinson has seen a dramatic reduction in post-crash fires in its legacy helicopters, the R22 and R44, since introducing partially compliant CRFS for those models. Skip Robinson Photo

Early indications are that the group will lean toward partial compliance or performance-based solutions, rather than strict compliance with the prescriptive standards in 14 Code of Federal Regulations (14 CFR) §27.952 or §29.952 (for fuel system crash resistance) and §27/29.562 (for dynamic crashworthiness).

Because meeting the letter of the law can be difficult and expensive for legacy rotorcraft designs, performance-based standards could allow for swifter adoption of life-saving enhancements in newly built helicopters. They would also reward the efforts of manufacturers who have already incorporated effective crash safety enhancements in their aircraft, even though those enhancements may not fully comply with the provisions of 14 CFR.

However, that will still leave the problem of what to do with the thousands of helicopters that are currently flying without adequate occupant crash protection. The solution will likely involve a strong voluntary component on the part of the civil helicopter industry — which, despite a growing awareness of the importance of crash safety, has yet to actually prioritize it.

Learning the hard way

Dr. Dennis Shanahan is the chair of the FAA’s ROPWG. A former U.S. Army flight surgeon and commander of the Army Aeromedical Research Laboratory, Shanahan has dedicated his career to improving occupant safety, first in military aviation, and more recently in the civilian world.

As Shanahan recounted, the Army’s emphasis on helicopter crash safety had its origins in the experiences of the Vietnam War.

“We learned the hard way,” he said. “Historically, the crashworthiness requirements came out of Vietnam, where we were having a lot of crashes of helicopters, both due to enemy action and due to other problems. We were seeing fires [in which] people burned up when they otherwise would have survived; we were seeing some types of injuries like spinal injuries that inhibited egress of the helicopter.”

When the Bell UH-1 Huey came up for replacement, the lessons of Vietnam were still fresh in the minds of Army decision-makers, and crashworthiness became a priority for the Army’s next utility helicopter, the Sikorsky UH-60 Black Hawk.

The NTSB has investigated more than 135 helicopter accidents resulting in a post-crash fire since 1994, the year that the FAA adopted new fuel system crash resistance standards. Kelly Koopmans Photo

Although the Black Hawk design was substantially complete when Shanahan was assigned to the Army’s Biodynamics Research Division in the late 1970s, “the crashworthiness people who I was working with pretty much had carte blanche in putting what they felt was necessary in that helicopter,” he recalled. “So the Black Hawk was really a monumental change in thought. Basically it was built as a crashworthy helicopter.”

However, because the Army was primarily concerned with outcomes, its crashworthiness requirements were performance-based, rather than prescriptive. As Shanahan noted, there’s a practical reason for that.

“When you’re prescriptive, you’re bypassing good old American ingenuity,” he said. “You’re telling manufacturers and suppliers exactly how they will build a certain mousetrap. And when you do that, you’re limiting ingenuity tremendously. You can rely on American engineering by and large to come up with some brilliant solutions if you give them the leeway.”

The FAA was much slower to adopt tougher standards for crash resistance in helicopters. When these finally came in 1989 and 1994, they were much more prescriptive in nature, and complying with them was expensive. Even manufacturers who made occupant safety enhancements to legacy helicopter models often didn’t bother certifying these enhancements to the standards of §27/29.952 and .562.

For example, Bell Helicopter, which had converted all of its production helicopters to CRFS by 1991, didn’t certify the fuel systems in its legacy models to the latest standards. According to a statement by Bell manager of air vehicle systems and ROPWG member John Wittmaak, “Bell Helicopter believes efforts to certify currently in-production CRFS systems provide no benefit and ultimately delay availability and increase costs associated to retrofit solutions for pre-CRFS aircraft.”

The first report generated by the ROPWG — a cost-benefit
analysis of requiring all newly manufactured helicopters to comply with existing crash resistant seat, structure, and fuel system
regulations — confirmed the high costs associated with these prescriptive requirements. According to the report, strict compliance with existing standards in newly manufactured helicopters would cost the industry approximately $764 million over 10 years.

Robertson Fuel Systems and StandardAero recently received FAA STC approval for a retrofittable crash-resistant fuel tank for Airbus AS350 series helicopters. Robertson Photo

This figure should be taken with a grain of salt, as the task group that evaluated costs used nonstandard methodology to arrive at its estimate. Even so, it’s apparent that complying with the regulations isn’t cheap.

However, compliance may not be an all-or-nothing proposition. In May 2017, to satisfy a request from Congress, the ROPWG submitted an interim analysis of CRFS effectiveness to the FAA. That study found that even CRFS models that were partially compliant with the standards of §27.952 were just as effective as fully compliant models at preventing post-crash fires and thermal injuries.

As a result of this finding, the working group recommended to the FAA that it not pursue a requirement that all newly manufactured helicopters meet the full requirements of §27.952 and associated advisory circulars. Instead, for those helicopters that are not already being manufactured with CRFS, “achieving partial compliance at a level similar to current partially compliant models will be less costly and far less disruptive than meeting full compliance,” the group stated.

The ROPWG is scheduled to deliver a final report on its recommendations for newly manufactured helicopters — encompassing both CRFS and dynamic crashworthiness requirements — on Jan. 28, 2018. Shanahan was not able to discuss specifics of the report in advance, but confirmed that the working group is still recommending partial compliance with the existing regulations. “Our group is certainly looking much more at performance than prescription,” he said.

Coming together

After the ROPWG finalizes its recommendations for newly manufactured helicopters, it will turn its attention to how to incorporate crash safety improvements on existing rotorcraft. Due to the sheer number and diversity of legacy helicopters in the U.S. fleet, “that’s going to be a very complicated issue,” Shanahan said.

Even if the FAA does choose to mandate crash safety retrofits on legacy helicopters, such a requirement could take years to take effect. If the industry is going to achieve meaningful improvements in crash safety in the meantime, voluntary efforts will be critical.

It remains to be seen whether there is a will to make those improvements, but at least there is increasingly a way. While some manufacturers, including Bell Helicopter, have made CRFS retrofit kits available for their aircraft for years, such kits were simply unavailable for some helicopter models, including the Airbus AS350 series.

A high-profile fatal accident involving a Flight For Life helicopter in July 2015 called attention to the civil helicopter industry’s shortcomings in addressing crash safety. Now, the FAA is feeling pressure to act. Mike Reyno Photo

After the Flight For Life crash, Airbus prioritized development of a rupture-resistant fuel tank for the H125 (formerly known as the AS350 B3e), which has been available as an option since 2014. In December 2017, Robertson Fuel Systems and StandardAero finally achieved FAA supplemental type certificate approval for a retrofittable crash resistant fuel tank applicable to most models of the AS350 series, including the AS350 B3e and EC130 B4.

“It’s not a simple effort,” Robertson director of engineering Bill York said of the certification process. Robertson has more than four decades of experience designing and manufacturing CRFS for the military market, but the company had not designed a civil system for many years. Meeting the FAA’s current standards was a three-year project that necessitated several design iterations.

According to York, one of the most challenging and costly aspects of the certification was a 50-foot drop test of the tank installed in the structure of the aircraft. Robertson regularly conducts drop tests of fuel bladders at its facility in Tempe, Arizona, but the military does not require in-structure tests (and the ROPWG has also recommended that in-structure tests not be required).

After more than a dozen development drop tests, Robertson performed a successful drop test of the tank in the aircraft with the cargo swing installed, leading to supplemental type certification of the tank in full compliance with §27.952. The company has already started deliveries to Air Methods, which is one of the air medical operators that has voluntarily committed to retrofitting all of its aircraft with CRFS as systems become available.

Robertson declined to specify a price for the tank, but with all of the engineering work that went into the system, it’s safe to say it isn’t cheap. Cost is one of the biggest obstacles to operators voluntarily adopting crash safety enhancements. Another, closely related issue is weight; in a light helicopter like the AS350, the 50 pounds (23 kilograms) added by the Robertson fuel system can make or break a contract in the absence of a common industry standard.

“It’s hard for one operator to do something unilaterally and still remain competitive with others who choose not to do it,” Shanahan pointed out. “It really takes the whole community to come together.”

Designed in the 1970s, when the lessons of Vietnam were still fresh in the mind of Army decision-makers, the original Sikorsky UH-60A reflected an emphasis on occupant safety that has been carried forward into subsequent Black Hawk variants. Skip Robinson Photo

While raising awareness among people who operate helicopters is one step toward that goal, educating the customers who contract with helicopter operators may be even more important. In its investigation into the Flight For Life crash, the NTSB found that “those without an extensive aviation background were unaware that most newly manufactured helicopters were not required to meet the latest helicopter crashworthiness requirements.”

In its recommendations resulting from that investigation, the NTSB called on the Association of Critical Care Transport (ACCT), in conjunction with the Association of Air Medical Services (AAMS) and the Air Medical Operators Association (AMOA), to develop guidelines for those who purchase, lease, or contract for helicopters “regarding the equipment and systems that would enhance the helicopters’ crashworthiness, including, at a minimum, a crash-resistant fuel system and energy-absorbing seats.”

According to LifeFlight of Maine executive director and ACCT project lead Tom Judge, the organizations hope to have those guidelines ready in the second quarter of this year. The working group assigned to the effort has been pursuing an “interrogatory” format, recognizing that there are many different factors that must be weighed and balanced in the selection of any aircraft.

“What we’re trying to do is give people a framework for asking the questions, rather than prescriptively saying ‘you need to do this, you need to do that,'” he said. “This is something that I think can turn up the light and help people get to the best technology.”

Shanahan, who has been advocating for improved occupant safety for decades, said he’s encouraged by recent developments.

“What’s been heartening [is] now everyone seems to be getting much more knowledgeable about these issues and what can be done,” he said. “I think the industry as a whole is getting behind this and looking at this larger picture.”

Of course, the industry is also facing more pressure than it has in the past, he added. “There is this looming threat that if they don’t do it on their own, that it’s going to be regulated.”

Elan Head: