Thursday this week, 7th July, the FAA is holding a meeting in Fort Worth, Texas, to present proposals for a significant change in how Inlet Barrier Filters (IBFs) are certified. But there’s a problem. There is no justification for such a move, and it will hurt the industry.

An estimated 20,000,000 flight hours have been achieved by helicopters fitted with IBFs, without any reported accident or incident directly related to an IBF system. Thus there is no justified need to even tinker with the certification rules – but the FAA are planning significant changes which could effectively wipe out the companies making, certifying and supplying IBFs. While the existing STCs will remain valid, the possibility of getting a new STC approved will be near impossible for anyone other than the airframe manufacturers. At present, only Airbus Helicopters makes IBFs, and are thus in the best position to benefit.  Over 7,000 IBF systems are currently flying.

An IBF is a piece of equipment that significantly reduces the potential for engine damage.  Early systems were developed to protect military turbine engines operating in harsh environments and later adapted to provide the same safety and power margin protection for civil applications. IBF systems are known to significantly reduce erosion, damage as operating costs for turbine engines.  Typically, IBFs lead to lower engine operating temperatures, lower fuel burn, the elimination of Compressor/Turbine blade erosion, decreased wear in oil path/bearings, the prevention of ash compaction on turbine wheels and so on.

During a meeting held at this year’s Heli-Expo in Louisville, Lance Gant, Rotorcraft Directorate Manager, stated “Inlet Barrier Filters are nothing but goodness when operating in certain parts of the world.”  Furthermore, Mr. Gant confirmed that the current certification standards have not resulted in any “unsafe conditions”.  When asked about the intent of the proposed policy change, the FAA was unable to answer why the new policy was under consideration with no evidence of an unsafe condition.

The potential change in the rules means that IBF manufacturers will have to provide certain Intellectual Property (IP) from the engine manufacturers, which they are in turn unwilling to supply to a third party.  The engine companies necessarily talk to the airframe manufacturers, and the latter thus have access to the IP required.  On this basis, if the third party suppliers are eliminated from the market, the airframe manufacturers stand to win.

The FAA proposed policy statement No. PS-ASW-27/29-07 in which they say “The use of IBFs on rotorcraft is becoming a common occurrence. Because the airworthiness standards and rotorcraft ACs do not specifically address IBF installations, we have documented guidance for these installations in project specific issue papers. This policy captures that guidance“.  This seems odd bearing in mind they have happily approved STCs for IBFs for years.  The FAA clearly intends a thorough approach, as their consideration comes in no fewer than twelve sections

1.  General Design Considerations.
2.  Installed Performance.
3.  Inlet Distortion and Turbine Engine Operating Characteristics.
4.  Ice and Snow Protection.
5.  Alternate Air Source.
6.  Structural Considerations.
7.  Aircraft Cooling.
8.  Crew Alerting.
9.  Additional IBF Flight Test Considerations.
10.  Category A Considerations.
11.  RFM Considerations.
12.  Instructions for Continued Airworthiness.

Why is the FAA doing this? That is the $64,000 question given 20 million flight hours free of accident or incident. It would appear that the FAA have been prompted by EASA in Europe to “standardize” the rules between EASA and FAA, and the EASA rules are already stricter.  For example, Aerometals has been trying to get its IBF certified for the Turbomeca-powered EC135 for over five years and the EASA continues to block this despite the FAA having certified it on a PWC-powered EC135

Who stands to win? As outlined above, the airframe manufacturers stand to benefit because only they have access to the IP from the engine manufacturers.  Additionally, engine overhaulers will be happy, because the less IBFs there are out there flying, the sooner an engine will need an overhaul, and up goes their income.

Who stands to lose? There are principally two IBF manufacturers – Aerometals and Donaldson, while Pall Aerospace competes in the same market but has slightly different technology which is closer to a Particle Separator than an IBF. Aerometals is a privately owned company which would be decimated if the FAA goes ahead, while Donaldson is part of a larger holding company would could afford to lose a division, even though that is a far-from-preferable outcome.  Vicariously, operators will lose as engine overhaul costs go up, leading to helicopter operating costs going up and the only way that can be reconciled financially is to raise operating charges to customers.

Aerometals submitted an initial FAA Supplemental Type Certification (STC) application in March of 2012 for an IBF system for the Sikorsky S-92 and has yet to receive FAA approval after extensive testing and burdensome new methods of compliance following an FAA “issue paper” outlining over 90 (yes, 90) new requirements on a company with significant experience in this market. Aerometals has several other projects that have been halted because of changing FAA guidance under unclear circumstances including the EC135T2/T2+ and the H130.  Aircraft owners and operators continue to wait for new engine protection systems under development with no clear approval timeframe.

HeliHub.com contacted Michael Huggett, the Rotorcraft Director of certification for the FAA, but he declined our offer of an interview. It seems strange that the FAA would refuse the offer to put their side of the story when they could be in a position to allay any fears. But perhaps they just intend steam-rolling their plans through and have no consideration of the consequences on the industry?

Rex Kamphefner from Aerometals told us that if the FAA goes ahead, he faces making “dozens of redundancies” and potentially closing the company.  He plans two particular approaches in response to FAA ratification of the new rules. Firstly, a legal challenge to the FAA not following their own rules, which runs along the lines of “never changing the basis of the rules under which they work”.  The second option is political one involving Senators and a big media push.  It is also clear that Donaldson would also be very unhappy indeed if the FAA progressed.  Pall Aerospace declined the offer of talking to HeliHub.com to present their views in this article.

Both Bell and Leonardo Helicopters confirmed to HeliHub.com that they have no plans to make IBFs themselves at this time.  Sikorsky is an active customer of Aerometals, who told us that the Lockheed Martin company is supportive of ensuring the third party companies continue to be able to freely produce IBFs as at present.  As noted above, Airbus Helicopters are the only major manufacturer of civilian helicopters who make their own IBFs and thus the likely major beneficiary.  It would be untenable that any manufacturer or a major engine overhaul organisation could have lobbied the FAA for this.

If the FAA can come up with this initiative for IBFs, what other after-market STC products are at risk next?  Is the whole STC landscape going to change?

Jeremy Parkin – HeliHub.com