Whither the Single-Engine IFR Helo?

By Staff Writer | June 1, 2015

Forty years ago, Vought Aircraft and Sperry collaborated to produce the SA-341 IFR Gazelle. This first IFR-certified single-engine helicopter was a breakthrough.

“This new world of single-pilot IFR represents the removal of one of the last major barriers to realizing the full potential of commercial helicopters,” wrote A.G. Bud DeLucien in the July/August 1975 issue of Rotor & Wing.

But new barriers were thrown up in 1999, when the FAA changed its certification guidance to impose stricter reliability requirements on new helicopters and modifications to existing ones. The new guidance stopped the development of single-engine IFR helicopters cold.


Now industry leaders are trying to fix that by persuading the FAA that reversing the 1999 change would substantially improve helicopter safety. Making it easier to equip more single-engine helicopters for IFR flight would have numerous safety benefits, proponents of the reversal argue. Foremost among the benefits would be eliminating the temptation for lone pilots to try to fly under bad weather and risk death by getting disoriented and losing control or colliding with terrain.

“It comes down to evaluating how we improve the overall safety of the product in the field,” said Walter Desrossier, vice president of engineering and maintenance for the General Aviation Manufacturers Association (GAMA). “Today, the standard is set at such a high level that we are not delivering IFR-certified Part 27 aircraft at all.”

GAMA is working with AHS International, the Aircraft Electronics Association and the Helicopter Association International to persuade the FAA to rectify that. They plan to present a consensus white paper arguing their case to the FAA this month.

In 1975, DeLucien, an R&W contributing editor, saw the IFR Gazelle as the midpoint in a five-step “natural progression to full utilization of helicopters.” The first two steps were introduction of two-pilot IFR in medium/heavy twins and the FAA’s adoption of rules—in the form of Special Federal Aviation Regulations (FAR) Part 29—to permit wider use of helicopter IFR.

Following the single-engine IFR certification, he wrote, would come “the widespread implementation of off-airway IFR routings and special airspace for helicopters” and “increased sophistication in equipment and greater aircraft capability.”

Things didn’t work out that way.

Vought sold “quite a few IFR Gazelles, 25 or 30,” said Jake Hart, the flight test pilot who worked on the project. Other manufacturers followed the lead of Vought and Sperry. Some Bell Helicopter 206L LongRangers were modified and certified for IFR flight. In the mid-1980s, Aerospatiale collaborated with the avionics maker Sfim on a one-off IFR AS350 for Black Beauty Coal of Indiana.

But when the successor company Eurocopter went back to the FAA to discuss broadening the supplemental type certificate for that AS350 to cover more aircraft, the aviation agency said the manufacturer would have to modify the AStar’s design to reduce the consequences of component failures in IFR flight, Hart said. Eurocopter opted not to take on the cost of that work.

Certainly, wider adoption of single-engine IFR was stymied by the lack of an IFR route network for helicopters.

But the 1999 change was devastating to single-engine IFR development. The change came in the FAA’s revision of Advisory Circular 27-1, its guidance on how to comply with Federal Aviation Regulations Part 27. That part prescribes airworthiness standards for Normal category rotorcraft with maximum weights of 7,000 pounds or less and nine or fewer seats, including most single-engine helicopters.

The agency had previously revised guidance for Part 23, which covers fixed-wing aircraft in the Normal, Utility, Acrobatic, and Commuter categories. The FAA reduced the reliability levels, or design assurance levels, that a manufacturer or modification shop had to demonstrate to get a type certificate or STC.

Prior to the change, these smaller airplanes had to demonstrate the same levels as big airliners. But FAA officials concluded that the higher standards didn’t correspond to the operating environment or experience of general aviation airplanes and smaller commercial ones. They also concluded that the higher standards were not improving safety, as they explained in the introduction to AC 23.1309-1C (which revised the standards).

“Since most aircraft accidents are caused by something other than equipment failures, increasing the reliability of the installed systems to try to improve safety will have little positive effect on reducing aircraft accidents when compared with reducing accidents due to pilot error,” the AC said. “If systems are required to meet safety and reliability parameters much greater than the operational environment, the cost of the improved systems are driven to a level that makes them impractical.”

The FAA went in the opposite direction with the AC 27-1 change, setting “numerical means of compliance for the light helicopter systems safety assessment” on part with those for jumbo jets. For example, under the new guidance, to demonstrate that the failure of a system on a light helicopter was “extremely improbable,” an applicant for a type certificate or STC had to show that it would not suffer a single failure in one billion flight hours. To achieve that, some systems on an IFR light single would have to be triply redundant. Such an aircraft would be prohibitively expensive to build and operate.

The impact of the AC change would not become clear for decades to innovators like Jim Irwin, president and CEO of Cool City Avionics of Mineral Wells, Texas. He has been working on developing autopilots—key components of an IFR kit—since he went to work for Mitchell Industries in Mineral Wells in 1967. He has worked with Hart on a number of occasions.

Irwin acquired his commitment to instrument flight when he was in the U.S. Army serving as an instructor pilot at Fort Rucker in what the Army called the Tactical Instruments course. “We did a lot of instrument flying in Alabama and up to Georgia,” he said. “It was clear back then that instruments was a good, safe way to go.”

In 2004, Irwin formed Cool City to pursue development of low-cost avionics, including an IFR-capable helicopter system. Last year, Cool City received an STC for the installation of its family of six autopilots in Robinson Helicopter R44s. But Irwin said he was surprised to discover how hard it was to get IFR certification for a single-engine helicopter.

“I didn’t realize how serious the changes were,” he said. “I was still thinking the biggest impediment was cost.”

FAA officials discussing the matter with representatives of the joint association effort say they want to see a clear safety case for changing AC 27-1 back. The proponents think they have.

Today, major contributing causes to helicopter accidents include inadvertent flight into instrument meteorological conditions (IIMC) or controlled flight into terrain (CFIT) while attempting to fly under weather conditions remain. This is especially true for accidents involving single-engine rotorcraft.

From 2001 to 2013, data gathered by the International Helicopter Safety Team shows, there were 194 accidents worldwide involving single-engine helicopters, IIMC or CFIT and low-level flight to avoid weather. (Fifty-seven occurred in the U.S.) Of the worldwide total, 133 were fatal accidents that killed 326 people. None of the accident helicopters were IFR-equipped.

For multi-engine Part 27 helicopters and larger (Part 29) rotorcraft in the same period, there were 54 accidents worldwide related to IFR-certified aircraft with IIMC or CFIT while flying low due to bad weather. Only seven involved flights under IFR rules; 40 involved helicopters flying VFR. Eighty-five percent (46) were fatal. Twelve of the total occurred in the U.S.

In most cases the multi-engine rotorcraft were IFR-equipped, the proponents said, but often the pilot had no instrument rating, was not current or had minimal instrument experience and was not confident in IFR procedures. In addition, most of the accident rotorcraft were models with older, “steam gauge”-style IFR instrumentation. These require a much greater degree of skill to interpret than modern displays, and therefore require a greater degree of practice in order to remain proficient.

That data only shows a portion of the problem, the proponents said. It does not capture the near misses of obstacles and terrain that occurred trying to avoid weather, or the near losses of control that occurred attempting to exit IIMC.

Hart said he believes the safety case is evident.

“If people look at it intelligently, and look at the hazards, it’s pretty clear that IFR would be a major safety advantage,” he said.

Another reason to revisit the AC now, the proponents said, is that systems and safety equipment that were unavailable in 1999 “are now readily available at reasonable cost, thanks largely to the strength of the small airplane market.”

“These systems are mature, highly reliable and dramatically reduce pilot workload while markedly increasing a pilot’s situational awareness,” they said in the draft white paper.

The trade associations don’t want to stop at changing the AC back. Their draft white paper outlines other step for the agency to take.

They urge the FAA to “harness advances in technology to enable a practical certification of safety-enhancing IFR type certificate or STC kits for new and existing Part 27 single-pilot, single-engine helicopters.

They want to the agency to “continue advocating for the development of low-level IFR helicopter infrastructure and Point-in-Space (PinS) approaches to areas of helicopter interest by leveraging ADS-B technology and advanced aircraft system.”

They also want it to advocate for “continued government and private investments in improved and expanded weather reporting and on-board detection technology.”

Lastly, they call for “an industry-wide campaign to increase the regular and routine use of the IFR infrastructure with the goal of reducing the overall risk of helicopter flight operations.”

International rotorcraft manufacturing leaders will be working over the next several months to define a framework for a joint review of U.S., European and Canadian standards for the certification of vertical-lift aircraft.

Their objective is to work with the top international rotorcraft regulators to identify and remove regulatory and bureaucratic obstacles to swifter implementation of technological advances and safety enhancements in helicopters, tiltrotors and future vertical-lift aircraft. A number of factors beyond that objective play into the initiative.

For one, certification is getting more expensive as rotorcraft get more sophisticated, particularly in their adoption of advanced flight controls and aircraft systems management avionics. The cost to gain type certification of new, medium, twin-engine helicopter now exceeds $1 billion, according to some industry officials.

For another, budget crunches in the U.S. and Europe mean that regulators there will have fewer resources (in terms of skilled personnel and funding) to oversee a growing number of certification applications, some of which are increasingly complicated.

In addition, some top safety officials are bracing for the prospect that the International Helicopter Safety Team (IHST) will miss its goal of achieving an 80 percent reduction in the number of helicopter accidents worldwide from 2006’s level. The IHST’s self-imposed deadline for achieving that goal is next year.

Lastly, regulators show signs of shifting their safety focus. At the FAA Rotorcraft Safety Conference April 21-23 in Hurst, Texas, for instance, top FAA rotorcraft officials said they want to take a close look at why occupant protection equipment has not been incorporated as fast in helicopters as it has been in automobiles. They are soliciting a discussion with industry input on helicopter survivability and proposing to review their internal procedures to identify easily cleared obstacles to improved survivability measures.

That concern is driven by the fact that IHST data shows that while annual accident totals have declined since it began work nine years ago, annual fatal accidents have not.

The work underway to assess the need for a review and reorganization of rotorcraft airworthiness standards is a direct result of the success of industry and international regulator collaboration on a reorganization of the U.S. Federal Aviation Regulations Part 23 and European Aviation Safety Agency Certification Specifications (CS) 23 governing type certification of general aviation and small commercial airplanes. Over the course of several years, regulators and manufacturers collaborated on a review of those rules.

Recommendations from that work are being acted on now in the U.S. and Europe.

For example, the General Aviation Manufacturers Association (GAMA) in March praised EASA for issuing an Advanced Notice of Proposed Amendment to modernise the way smaller airplanes are certified. “We are pleased to see EASA take this important step forward,” GAMA President and CEO Pete Bunce said.

The proposed rule is largely based on the work of the FAA’s Part 23 Aviation Rulemaking Committee, which was co-chaired by GAMA and included participation of international aviation authorities and global industry.

Building on Success

The CS/Part 23 initiative “seeks to increase the safety of general aviation airplanes and promote the introduction of new technologies while reducing the burden and costs of certification by focusing on safety performance requirements,” Bunce said. “The prescriptive means of compliance are being set through globally agreed-upon consensus standards” developed collaboratively “international regulators, manufacturers, and the global aviation community. Under the initiative, each of the world’s aviation authorities will modernise its design certification rules.

Given GAMA’s success with the CS/Part 23 reorganization, that trade group is leading the efforts to craft a framework for reviewing CS/Parts 27 and 29 governing rotorcraft certification. It is working with the AeroSpace and Defence Industries Association of Europe (ASD).

The 27/29 initiative “has come out as a direct consequence of the restructuring and reorganization of Part 23 and the success that the FAA, EASA and industry have had in putting forward a more streamlined set of regulations and the construction of acceptable means of compliance,” said Jonathan Archer, GAMA’s director of engineering and airworthiness. “We were then able to transfer those into industry-consensus standards using the standards development organization ASTM International. “

The FAA solicited industry interest in a review of Parts 27 and 29 in 2013 and received dozens of responses. The agency was spurred to do so by language in the 2012 FAA Modernization and Reform Act, specifically Section 312, “Aircraft Certification Process Review and Reform.” That section of the law continues to drive implementation of numerous improvements to the certification process. Those include the FAA’s revisions of its procedures for processing applications for supplemental type certificates and its management of Organization Designation Authorizations held by original equipment manufacturers and major modification shops.

But Archer said the response to the FAA’s notice was a clear indication that “there isn’t a strong regulatory framework in place for the introduction of new technology.”

The CS/Part 27 and 29 initiative ultimately seeks to create such a framework.

Discussions with the FAA’s Rotorcraft Directorate established that “there is a window of opportunity for industry to propose a set of recommendations on areas within Parts 27 and 29 that could be prioritized and reviewed or restructured,” said Walter Desrossier, GAMA’s vice president of engineering and maintenance. That window of opportunity was created in part by Section 312.

At Heli-Expo in Orlando last March, GAMA officials met with international manufacturers’ representatives to begin discussions toward that goal.

“A key question is whether the subject of the review is the whole Parts 27 and 29 or just key areas that the industry feels are the biggest bottlenecks,” Archer said. “Alternately, we may want to look at how changing certain sections might introduce the greatest safety benefits in a streamlined fashion.”

Another potential benefit is harmonization of certification standards across borders. The disparity in certification standards and their interpretation was highlighted by Bell Helicopter’s petition to increase the maximum takeoff weight of its 429 by 500 pounds beyond the Part 27 limit of 7,000 pounds. A higher maximum takeoff weight would trigger certification to the more stringent standards of Part 29.

A number of aviation authorities around the world granted Bell’s petition, including Transport Canada. But EASA and the FAA rejected it. One reason was a concern that such an exception would give Bell an unfair advantage in the marketplace.

GAMA’s coordination with ASD is critical. Since the Heli-Expo meeting, the groups have been working to forge a broader consensus among U.S. and European manufacturers “so we can have a complete EASA/FAA perspective, which will then drive a more harmonized set of regulations,” Desrossier said.

“The importance of any kind of review and any kind of recommendation, especially to change something as foundational as airworthiness standards is that they be consensus recommendations.”

CS/Part 27 and 29 are the basis of the world’s rotorcraft standards, he said.

Harmonization is critical, Desrossier said. “For rotorcraft manufacturers, theirs is a global market. If we try to propose changes to those standards and we don’t do it in a harmonized way to get global buy in, then ultimately it’s not going to facilitate the ability for a manufacturer to use those new standards.,” he said. “You can’t design and certify to a new standard if it is not going to recognized and accepted globally.

The industry representations are to work through the third quarter of this year in developing recommendations for a framework review. Those recommendation are to circulated to the broader industry in late 2016. After that, the groups would make their proposals for a review to EASA, the FAA and Transport Canada.

FAA Seeks More Scientific Evidence

On Aircraft Noise and Communities

The FAA plans to shortly begin work on the next step in a multi-year effort to update the scientific evidence on the relationship between aircraft noise exposure and its effects on communities around airports.

“The FAA is sensitive to public concerns about aircraft noise. We understand the interest in expediting this research, and we will complete this work as quickly as possible,” said FAA Administrator Michael Huerta.

Beginning in the next two to three months, the FAA will contact residents around selected U.S. airports through mail and telephone to survey public perceptions of aviation noise throughout the course of a year.

This will be the most comprehensive study using a single noise survey ever undertaken in the U.S., the agency said, polling communities surrounding 20 airports nationwide. To preserve the scientific integrity of the study, the FAA cannot disclose which communities will be polled.

The FAA obtained approval from the Office of Management and Budget last week to conduct the survey and hopes to finish gathering data by the end of 2016. The agency will then analyze the results to determine whether to update its methods for determining exposure to noise.

The framework for this study was developed through the Airports Cooperative Research Program (ACRP), which is operated by the Transportation Research Board of the National Academies of Sciences. This methodology will be used to determine whether to change the FAA’s current approach, as well as consideration of compatible land uses and justification for federal expenditures for areas that are not compatible with airport noise.

Aircraft noise is currently measured on a scale that averages all community noise during a 24-hour period, with a ten-fold penalty on noise that occurs during night and early morning hours. The scientific underpinnings for this measurement, known as the Day-Night Average Sound Level (DNL), were the result of social surveys of transportation noise in the 1970s.

In 1981, the FAA established DNL 65 decibels as the guideline at which federal funding is available for soundproofing or other noise mitigation. This method was reaffirmed in studies conducted during the late 1980s and early 1990s.

For anyone who feels uneasy about the process for obtaining a supplemental type certificate (STC) in 2015, you’re in good company.

Making aftermarket changes to an aircraft has got to be a tense enough experience, especially with operators having to invest tremendous amounts of their time, capital and workforce before they even know whether their application is approved.

But recent changes to the FAA’s certification body have called into question whether traditional methods will even work anymore. In light of apparently growing mystification, Rotor & Wing looked into how organizations large and small are getting STCs, and hopefully their experiences can shed some light on the best way to authorize your much-needed modifications so you can get back to the business of flying.

Structural Changes

On Jan. 28, 2015, Helicopter Association International (HAI) hosted an Industry-Government Forum in Alexandria, Va., giving members of the rotorcraft industry a chance to hear directly from and pose questions to FAA representatives on a number of pressing topics. One of the first and most active discussions was the effect the recent FAA restructuring would have on the STC application process. As the Lance Gant, assistant manager of the FAA Rotorcraft Directorate, explained, the agency had been finding it increasingly difficult to balance industry needs with its limited resources.

For starters, the bandwidth and technical capacity of Aircraft Certification Offices (ACOs) to oversee STC applications weren’t enough to handle the incoming requests.

On top of that, holders of organization designation authorizations (ODAs)—“super” delegations from the FAA to approved manufacturers and modification shops created to alleviate the agency’s certification workload—often still required a great deal of FAA oversight to function.

“Those of you who have ODAs know that ODAs are not really seen as effective as they should be at this time,” said Gant. “We’re hearing that not only from you, the industry, but from Congress.”

As a result, the FAA consolidated its Southwest Region certification offices It combined its three ACOs serving non-ODA-supported businesses into the single, full-service Fort Worth ACO. It then created a centralized office to oversee ODAs, called the Delegated Systems Certification Office (DSCO).

So why decrease the number of ACOs? One reason given by Gant is that incoming requests will now be assigned by a small program management team to one of the many journeymen engineers in the office, rather than the old protocol of allowing the much larger engineering group to cherry-pick projects. Hopefully, this will translate into faster turnaround time for STCs.

Many believe that the decisions the FAA is making are ultimately positive, but—as is the case with all large corporations—change takes a long time. For now, even four months later, the process for getting an STC still seems to move at a snail’s pace.

According to some in the industry, it may take more than a shift in logistics to alleviate the bottleneck. Already hurting from the effects of sequestration, the FAA is strained by a dwindling workforce, while the speed of technological innovation in the rotorcraft industry is increasing.

More STC requests are coming in than in years past, and many are new applications of technology never before addressed. According to Ric Peri, vice president of government and industry affairs at the Aircraft Electronics Association (AEA), that combination isn’t a recipe for efficiency.

“The downside is that while aircraft certification at the FAA is probably one of the more progressive divisions (looking at the FAA holistically rather than at individual offices), the individual certification process is still hugely independent,” he said. “So you end up having to educate the FAA engineer on the technology as part of the process. And then every time you take the project to a new ACO, it starts that process all over again.”

On top of that, Peri said, the FAA—like any corporation of that size—has a fair amount of turnover in individual job assignments. Every time an engineer turns over in a project, that project backtracks to bring the new engineer up to speed. “These are things that are really killing the industry, and causing huge price overruns, and frustration,” he said.

Add to that a persistent belief that the FAA has a dual mandate of fostering growth in aviation while simultaneously advocating for its standardization and safety. The increase in number and technical complexity of STC requests is at odds with the traditionally wary agency. As Peri said, “It’s very difficult for an engineer to embrace new and novel technology and still be risk-averse.”

Given that the FAA’s changes are primarily internal, the two-step initial process for requesting STCs is largely unchanged. A business wanting to make what qualifies as a “major change” to an aircraft’s type certificate decides whether to seek STC approval or attempt other means of certification.

If an STC is required, the business contracts through an ODA or a designated engineering representative. The former is more common among OEMs and larger operators with high overheads. The DER is a design engineer who takes on the management of getting the STC ready for approval.

In his work with the AEA, Peri has dealings with many businesses applying for avionics-related STCs. He said he has seen how critical these first two steps are in avoiding major roadblocks later on in the process.

Determining first if a modification actually requires an STC can save a business the tremendous frustration of doing work up front for nothing. This may seem like an easy task, but the FAA has periodically changed the criteria for what requires a given certification.

Hazards of the Process

“The bottom line is that there were a number of technologies that the FAA Rotorcraft Directorate deemed to be new and novel technology and had elevated the installation criteria to STC,” Peri said. “They have since, as a result of efforts going on for three years now, revised a number of those technologies and backed them down to a normal major alteration.” ADS-B Out and helicopter terrain avoidance systems (HTAWS) are two high-profile examples.

As bad as it may seem to go through the STC process unnecessarily, the reverse mistake can be even worse. One helicopter operator that preferred not to go on record reported actually losing a client after seeking field approval for a particular modification, only to find out from the visiting FAA inspector that the request would require an STC.

When it comes to the second step, contracting a DER, Peri cautioned against making the choice too easily. Not all DERs are well-suited to handling the paperwork-heavy, complex STC process.

“What happens is that a lot of maintenance shops will act as a general contractor, but they don’t have the resident regulatory and FAA relationship background to effectively pull it off,” Peri said. “It’s very similar to someone who tries to be a general contractor for having a house built, but really doesn’t understand the relationship between the different trades.”

A good DER should not only be a qualified engineer, but also a good project manager—preferably with past experience specifically managing an STC process.

Finally, the DER should have prior experience with the category of aircraft being modified, as well as with the technology being applied.

Airbus’s AS350 was a relatively early implementer of single-engine IFR in the mid-1980s.Flight test pilot Jake Hart, who worked on the IFR Gazelle, says IFR’s safety benefits are “pretty clear.”In 1973, this magazine saw great promise in bringing IFR capabilities to helicopters, as Barney Green testifies. Cool City Avionics head Jim Irwin (left, with Jeff Kelly of Kelly Aerospace Power Systems) gained an appreciation for IFR at Fort Rucker in the 1960s. Photo courtesy of Cool City Avionics.A modern Gazelle (above, courtesy of Davide Olivati). Vought Aircraft and Sperry collaborated in 1975 to produce the SA-341 IFR Gazelle, the first single-engine IFR-certificated helicopter (top right).

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