Helicopter crash survivability in focus: Part 2
Amy Gallagher details challenges to FAA regulations that have previously allowed helicopters to slip through without meeting safety standards to aid crash survivability
The 2015 Frisco crash in Colorado, US, resulted in the tragic death of Patrick Mahany, US Army and Flight for Life (FoL) Pilot and husband of Karen Mahany, and left Dave Repsher, FoL Flight Nurse, with burns over 90 per cent of his body and a 140 per cent negative chance of survival. Now, Karen, Dave and his wife Amanda Repsher – known as the Frisco Three – are extensively campaigning to overcome the regulatory obstacles held responsible for the unsuitable crashworthiness that led to Patrick’s death.
In part one, AirMed&Rescue detailed the regulatory shortcomings and the Helicopter Safety Investment Tax Credit proposed by the Frisco Three. This final installment takes a closer look at the FAA response, including its December 2020 white paper, and industry feedback.
Crashworthiness regulations and survival rates
Dave Repsher and Dennis Shanahan MD, retired US Army Master Flight Surgeon and committee member that drafted the definition of crashworthiness features required in all new US Army helicopters, spoke of the velocity factors of the helicopter as applied to rotor safety. “In order to gain certification, the regulation requires that the fuel system must survive a 50-foot drop filled to 80 per cent capacity without leakage for 15 minutes, which corresponds to an impact velocity of 57 ft/sec,” said Repsher. “Our crash, at the center of gravity where the fuel tank was located, was estimated to have impacted at 42 ft/sec and filled to only 57 per cent capacity. These figures show that had the helicopter been equipped with a certified crash-resistant fuel system (CRFS), despite the violent nature of the crash, that we were well within the tolerance area.”
In 1989, Shanahan worked on addressing the specifics of the Survival Factors Group of the National Transportation Safety Board (NTSB). “One of those specifics is the velocity rate,” he said – the speed in feet per second without rupture to the fuel cell. “As an example of the military’s Blackhawk and Apache, the velocity is 60 ft/sec without rupture of the fuel cell,” he explained.
For the Frisco crash, the survival factors calculate the 42 ft/sec velocity rate which is close to the design limit for an US Federal Aviation Authority (FAA) compliant fuel cell, said Shanahan. “All indications are that a CRFS would have made all the difference in the world for these folks.”
More emphasis on helicopter occupant protection
The FAA is trying to justify these old standards as adequate despite their own admission of their ‘inability to achieve sustained fatal accident reductions over time’. If these standards were adequate, why did the FAA go through the trouble and expense of developing the ‘new’ 1989 and 1994 standards?
The FAA organizes helicopter safety and design into two groups: accident avoidance and occupant protection. While the FAA emphasizes developing accident avoidance systems, which are incredibly sophisticated today, those systems are also very expensive and don’t always align with occupant protection, according to Shanahan: “Their rating system concept shows little emphasis on operations, which is much less expensive. More importantly, the FAA White Paper does not show how it will prevent accidents and deaths.”
This emphasis stems from a zero-defect philosophy originating in the 1970s, when it was believed that all accidents could be prevented with sufficient technology and money applied to vehicle design and composition. Shanahan continued: “This goal was not achievable then, and it is not achievable now. Any system developed, constructed, and operated by humans will have occasional defects. For this reason, vehicles too should also be designed to protect occupants in the event of an inevitable crash. Put simply: it is the zero-defect philosophy that is flawed.
“By 1980, we had crash-resistant fuel systems in almost every helicopters. The overriding philosophy in the Army after the ‘70s was that there was no justifiable reason for people to die of thermal injuries or blunt force trauma in survivable helicopter crashes. The technology for preventing these injuries was available and relatively inexpensive, particularly when compared to the cost of the loss of human life. It was my hope that this same philosophy would be adopted by the FAA and effectively applied to civil rotorcraft. That’s why I agreed to chair the Rotorcraft Occupant Protection Working Group (ROPWG) when I was approached by the FAA and the ROPWG developed a comprehensive plan on how to make this a reality.”
The influence of the ROPWG continues, as Jeff Trang, VP of Flight Operations at Airbus Helicopters, noted: “Airbus Helicopters participated in the ROPWG in a collaboration between the helicopter industry, aircraft operators, and the FAA.”
2018 Safety Act: CRFS loophole yet remain in place
Back in 2018, AirMed&Rescue published: “As of November 2014, the FAA aircraft registry includes more than 5,600 helicopters manufactured since 1994. However, of those, according to certification data provided by the FAA, only about 850 (15 per cent) are models with CRFS that meet the 1994 requirements.” When asked for an update on the agency’s aircraft registry on helicopters with CRFS certification data, the FAA did not respond.
The Helicopter Fuel System Safety Act of 2018 attempted to close this loophole regarding CRFS; as of April 2021, all newly manufactured helicopters must meet the 1994 requirements. “However, due to a fleet turnover rate of just one- to two-per-cent, and a 30-plus year lifespan of a helicopter, it will be many years before an appreciable impact will be noticed,” Shanahan said.
Repsher agreed: “The loophole regarding crashworthy seating and structure remains in place, meaning that to this day, the bulk of newly manufactured helicopters (around 90 per cent) are not in compliance with the rules set forth in 1989. This is of critical importance as most helicopter crash fatalities are a result of blunt force trauma and survivors are left facing long battles with traumatic head injuries, spinal cord injuries, psychological trauma, and burns.”
Despite its size, the rotor industry only represents eight per cent of the aviation industry, leaving it at ‘a significant disadvantage in terms of competing for both time, space, and supervision within the FAA,’ Repsher elaborated. “The FAA is also greatly inhibited by its charter, mandates, and regulations.” As such, the goal of the Helicopter Investment Tax Credit of 2021 (detailed in AirMed&Rescue Aug/Sep 2021, pg 14) is to provide tax credit for all new, properly equipped helicopters. “The staggering loss of life and catastrophic injuries that survivors endure has been tolerated by the industry and regulators for far too long,” said Repsher.
Regardless, Alex Aloccio, Head of the Light Helicopter Program at Airbus Helicopters, was keen to emphasize the value of CRFS: “Many key safety components already come standard on our products, and we provide multiple retrofit solutions for earlier models. For example, attenuating seats come standard on our H130 and we are finalizing retrofit solutions for the H125. Crash resistant fuel cells come standard on our entire light helicopter range and retrofit options exist for earlier variants. We strongly encourage our customers operating without CRFS today to retrofit their fleet with these systems.”
FAA proposes safety promotion concept for design and equipment
The FAA’s White Paper, FAA Rotorcraft Safety Rating Concept for Design and Equipment AIR-616, Strategic Policy Rotorcraft Section was published in December 2020. According to the FAA website, it promotes voluntary options for enhancing safety for six different categories of rotorcraft design and equipment, ranked from one star (safe) to four stars (highest safety). The purpose is to better inform and educate rotorcraft stakeholders and promote increased voluntary equipage – the equipment for a particular purpose – in areas that have the potential to reduce fatal accidents.
When asked to expand on the FAA’s rotor rating concept, Tony Molinaro, FAA Public Affairs Officer, said: “We are working on an initiative that was touched on in the [December 2020] white paper, but that plan is being updated.”
Safety enhancements for the three Occupant Protection categories were typically not required for all newly manufactured or already-in-service rotorcraft. As a result, older designs not incorporating the later safety enhancements are likely to receive a one-star rating for the minimum level of safety at the time of certification. A new design certified to the most recent regulatory standards would be more likely to have a four-star rating in each of the six categories. The greatest challenge of any idea is in the implementation of that idea without the follow-up details of how to sustain and implement their rating system.
For the three Occupant Protection ratings categories, rotorcraft with designs or equipment that are above a one-star rating have a reduced probability of fatalities or serious injuries when a survivable accident occurs. For the three Accident Avoidance ratings categories, rotorcraft with designs or equipment that are above a one-star rating have a reduced probability of being involved in those particular types of accidents.
The rating system concept is intended to assist stakeholders – suppliers and consumers – in making an informed risk-based decision. But the greatest challenge, according to the FAA, is ‘maintaining a public list’.
FAA Rotorcraft Safety Research Program
Cliff Johnson, FAA Senior Research and Development Engineer, said: “The first effort is Helicopter Flight Data Monitoring research to develop more robust helicopter data and new analytical tools designed for the unique nature of helicopter operations.” This research includes:
- collecting flight data from commercial and government operators
- exploring data monitoring as a voluntary means to improve safety across the industry
- developing secure and confidential safety analysis of aggregate flight data records
- supporting risk mitigation efforts
With operators volunteering to participate in the research program, Johnson said the FAA has developed several prototype safety metrics and analytical capabilities in support of various safety teams. “We also collaborate directly with the United States Helicopter Safety Team developing tools to use as part of Helicopter Safety Enhancement #82 on FDM,” he added.
The second effort is to investigate enhanced flight vision systems technologies to determine if they can improve flight safety and provide operational benefit for rotorcraft operations. Research efforts includes:
- examining head-worn and helmet-mounted displays symbology, information, and user interface
- characterizing multi-sensor infrared, millimeter wave, light imaging detection ranging performance in a range of weather conditions
- examine visual references helicopter pilots need to acquire both with and without advanced vision systems.
The third effort is to improve the development and testing of helicopter simulation models for ‘outside the envelope’ flight maneuvers representative of Loss of Control (LOC) encounters with researching flight test trials and simulations to develop new mathematical computational aerodynamic models of rotorcraft conditions and integrate new models for LOC conditions into existing and new simulators and advanced flight training devices.
Implementing new systems into legacy
Today’s helicopters are generations above their older versions in terms of resilience, automation, technology, and instrumentation, said Johnson. “Technologies like FDRs and Health and Usage Monitoring Systems (HUMS) play an important role and have been able to be used for accident investigation, as well as proactively identifying trends and potential safety issues before accidents or incidents occur,” he said. The challenge remains getting these systems onto legacy helicopters, said Johnson.
Shanahan notes the research initiatives mentioned by the FAA’s Johnson are directed toward accident avoidance and will take years to come to fruition: “The FAA could get essentially immediate results if they focused their efforts on implementing the requirements of the 1989 and 1994 standards into all helicopters.”
Justifying old standards in avoidance of future change
In its white paper, the FAA states: “Rotorcraft still have a perception problem with segments of the flying public who consider them unsafe. This perception is in part due to high profile fatal accidents and an inability to achieve sustained fatal accident reductions over time.”
However, Shanahan pointed out: “For all practical purposes, all helicopters flying today meet the emergency landing requirements existing prior to 1989, so it appears that the FAA is trying to justify these old standards as adequate despite their own admission of their ‘inability to achieve sustained fatal accident reductions over time’. If these standards were adequate, why did the FAA go through the trouble and expense of developing the ‘new’ 1989 and 1994 standards?”
Shanahan stated that while the FAA admit that helicopters designed to the pre-1989/1994 standards are resulting in unacceptably high fatality rates, they persistently hesitate on mandating actions to implement these ‘new’ standards into newly built and existing helicopters. “They continue to emphasize expensive and unproven accident avoidance schemes while resisting efforts to mandate proven occupant protection technologies,” said Shanahan. “Their intransigence in implementing these standards is costing lives.”
Given the FAA's continued resistance to implementing the 1989/1994 occupant protection standards, even after a working group that they formed provided a detailed road map for achieving this goal, I am convinced that future efforts in this area will have to be focused on Congress and the Frisco Three who have proven the efficacy of this approach, he said.
“I hope Congress picks up the tax credit legislative proposal and rewards those in the industry directly who do the right thing,” said Shanahan.