In the 5 November 2015 US Department of Transportation (USDOT) Federal Aviation Administration (FAA) Federal Register, Vol. 80, No. 214, the FAA published the results of an in-depth study of helicopter accidents involving post-crash fire and blunt force trauma, in response to the ‘unacceptably high’ fatal accident rates, notably two fatal accidents in July 2015 just 20 days apart. The study revealed only 16 per cent of the US helicopter fleet complied with the crash-resistant fuel system (CRFS) (14 CFR §27/29.952; Parts 27 and 29 of the Federal Aviation Regulation) required in 1994. Results from the same study showed that only 10 per cent met the emergency landing certification requirements of 1989, according to the Federal Register. Finally, the FAA study further concluded that 80 per cent of accident fatalities were caused by blunt force trauma; 20 per cent were caused by post‑crash fires. A fatal accident study showed both measures would have been effective in saving lives (Federal Register Vol 80 no 214).

Weight, power, cost, market, payload, makes and models, performance, fuel requirements, the helicopter is a matrix of variables that depend on the other to function. Increasing the weight of any aircraft will potentially reduce its useful payload; any impact this has on performance must be compared to the benefits provided by implementing increased safety measures. “A helicopter is a ‘system of compromises’,” said Alan Syslo, President, S.A.F.E. International, Inc. of Fort Worth. “CRFS are only a part of general aviation safety.”

Timeline for regulation change

The timeline to review and revise the 1994 CRFS certification is an example of how long the regulatory process can take. Syslo said that the initial recommendation from the National Transportation Safety Board (NTSB) to change the certification process for helicopter fuel systems was recorded in October 1985; however, it did not produce a rule change and briefing back to the board until June 1995, noting the rule change took place September 1994.

According to Syslo, the collaborative communications between the FAA and the NTSB show how seriously the FAA takes recommendations from the NTSB.

the collaborative communications between the FAA and the NTSB show how seriously the FAA takes recommendations from the NTSB

“I believe that the fact that we may be seeing a rule change in the near future on Recommendation A-15-012 that was issued as a result of an accident on 4 October 2014 shows that the FAA is definitely fast-tracking this issue as a priority,” he stated.

The principal challenge is the timeline within which the industry can make this transition, which may be more difficult for some models than with others, according to Airbus. “The long-term benefit is to ensure that all newly manufactured helicopters, regardless of the original certification date, are equipped with modern CRFS,” noted an Airbus spokesperson.

FAA-ARAC-ROPWG recommendations

In 2015, the FAA assigned the Aviation Rulemaking Advisory Committee (ARAC) to form a Rotorcraft Occupant Protection Working Group (ROPWG) to provide recommendations regarding occupant protection rulemaking in normal and transport category rotorcraft for older certification basis type designs that are still in production. The ROPWG is comprised of 22 technical experts with a wide range of industry experience (normal category rotorcraft manufacturers, transport category, rotorcraft manufacturers, and rotorcraft operators from various segments of the industry such as oil and gas exploration, emergency medical services, and air tour operators) who have been completing a series of tasks since 2015 required by the FAA to ensure all aspects of the tasks are considered in development of the recommendations.

After a nearly three-year study examining the factors affecting full or partial compliance of the CRFS in Civil Part 27 and Part 29 helicopters, the FAA is scheduled to brief the NTSB on 31 July on the recommendations resulting from the ARAC-ROPWG report.

Impending FAA decision

According to written responses from the FAA, the agency has not yet decided on potential CRFS and CRSS rulemaking for newly manufactured rotorcraft. Before the FAA issues any final regulations, a notice will be issued to allow the public to comment on any proposed regulations, including comments on the FAA’s economic analysis. The FAA will review the recommendations to prepare a proposal for rulemaking package after the Working Group completes its final report. The public will have an opportunity to review and comment on the FAA’s economic analysis.

Any impact that new proposed CRFS and CRSS (crash resistant seats and structures) regulations might have on current models in production would be considered in the FAA’s economic analysis

Any impact that new proposed CRFS and CRSS (crash resistant seats and structures) regulations might have on current models in production would be considered in the FAA’s economic analysis, which would accompany the regulatory notices in rulemaking publications. The economic analysis will address cost and benefits associated with new proposed regulations. Before the FAA issues any final regulations, a notice will be issued to allow the public to comment on any proposed regulations, including comments on the FAA’s economic analysis.

ROPWG ‘Partial Compliance’ report to FAA

In March 2018, the ROPWG report submitted to the FAA containing CRFS and CRSS includes the industry analysis of partial implementation of the relevant regulations. The Working Group determined that a subset of the regulations is nearly as effective as a mandate of full compliance to the regulations, and at a much-reduced price. The crash data for the current study was extracted from the NTSB Microsoft Access Accident Database and included the last 20 years of accidents involving US registered helicopters equipped with partially compliant CRFS at the time of the accident.

In a comparative analysis of Part 27 and Part 29 helicopters, the ROPWG’s research was based on 1,182 partially compliant and non-compliant accidents individually reviewed to determine the following:

• Whether or not there was a post-crash fire (PCF), and if so, the cause of the fire
• The severity (survivability) of the accident
• The number of occupants that sustained thermal injuries after surviving the accident impact.

The data show that the crash performance of the partially-compliant Part 27 helicopters, regarding the prevention of post-crash fires, is far superior to that of non-compliant helicopters and, for most partially compliant models studied, equally effective as fully compliant models.

NTSB response

The October 2017 letter from the Honorable NTSB Chairman Robert Sumwalt addressed the safety recommendation A-15-12, which the ARAC subcommittee presented to the FAA with responses from the NTSB. According to Syslo, the letter is an indication of a compromise that will likely be a way to improve the current system without grounding entire models of helicopters.

“However, what is missing from the discussion appears to be any reference to existing or ‘legacy’ aircraft that do not comply with CRFS,” explained Syslo. “These helicopters can fly effectively forever as long as there are parts available to continue maintenance. This is the only real hole I find in the current rulemaking; however, we have yet to know if there will be any acknowledgement of this in the final rule.”

A collaborative commitment

“It’s important to note that the recommendations of the ROPWG were not developed in isolation, but with input from operators as well as from OEMs,” said Airbus, which participated in the ROPWG. “Operators have also been very welcoming to the idea of CRFS retrofits on their aircraft that are not already equipped.”

The StandardAero/Robertson Fuel Systems CRFT is the only FAA-approved retrofit solution designed as a direct replacement for legacy AS350 models

Since 2016, all new Airbus helicopters delivered to the US market have been equipped with modern crashworthy fuel systems as standard equipment, and any helicopter that is not currently equipped can be retrofitted with a modern CRFS, said Airbus. According to the manufacturer: “We expect that the industry will continue to be deeply invested in finding ways of improving safety, and will address these issues collaboratively with operators and OEMs for the greater good of our industry and the flying public.”

StandardAero has received significant interest from both small and large fleet operators, said Rick Stine, President, StandardAero Components, Helicopters & Accessories. “We’ve been actively engaged with customers interested in enhancing their fleet with this new technology,” he said.

The StandardAero/Robertson Fuel Systems CRFT is the only FAA-approved retrofit solution designed as a direct replacement for legacy AS350 models, including the AS350 D, AS350 B/B1/B2/BA/B3 and AS350 B3e (H125), as well as for the EC130 B4, according to Stine.

“Our CRFT (crash-resistant fuel tank) kit solution is field replaceable, with a design that features a robust crash-resistant fuel bladder, slightly greater fuel capacity than the legacy tank, and introduces magnetic field sensor fuel gauging technology, a recessed sump drain valve, quick-change cartridge fuel pump design and vent system roll-over protection,” said Stine. Following the delivery of multiple CRFT kits to launch StandardAero’s customer Air Methods, and a separate Memorandum of Understanding (MOU) with Papillon Airways, Stine also said that StandardAero submitted its application for EASA approval of the CRFT-STC pursuant to the FAA and EASA bilateral agreement. “With Air Methods and Papillon investing in our CRFT, the launch of the programme is just the ‘tip of the iceberg’ when it comes to the overall safety-minded landscape,” said Stine.

EASA rulemaking task

The European Aviation Safety Agency (EASA) participated in the FAA-initiated ARAC working group tasked with assessing the options for the retrospective application of design changes for CRFS for rotorcraft, according to David Solar, Acting Head of Rotorcraft Department, EASA. “In parallel, EASA has included a dedicated Rulemaking Task (RMT) 0710 in the European Plan for Aviation Safety (EPAS) to consider the way forward for the retrospective application of CRFS based upon the recommendations of the ARAC working group,” Solar explained. “This RMT has not yet been initiated and the next step will be to prepare and approve the Terms of Reference (ToRs) in order to agree the scope of this activity.”

During this RMT, a Regulatory Impact Assessment (RIA) will be conducted to consider the effect of the proposed regulatory changes using different factors including safety, economic, harmonisation, social and proportionality, Solar further explained. “The different options will be considered against these factors in order to establish the most viable options,” he said.

In addition, Solar said the ARAC working group recommendations will need to be reevaluated in a European context based upon the use of European safety and economic data. The RIA would be included in a Notice of Proposed Amendment (NPA) which will contain the regulatory changes, and then consulted with the public.

“Only if the expected safety benefit of a new certification specification (standard) outweighs the grandfathering rights, then the aircraft manufacturer (type certificate holder), or operator/owner of aircraft could be required to comply with the latest certification specifications (standards),” he said.

This decision needs to consider the impact to operators of the aircraft and to the aircraft manufacturer (type certificate holder), whether the required changes are technically viable and what expected costs will be, Solar concluded.

So, much has still to be decided. Cost, of course, is a significant factor in the decision-making process. The data is clear, though – CRFS, even if partially implemented, can save lives in the event of a crash. It is now up to the FAA and EASA to decide how far new regulations will go to force operators and manufacturers to step up their safety levels.