February 29, 2016

In an effort to ensure awareness and prevent potential ramifications to the rotorcraft industry, we’re making you aware of a proposed Inlet Barrier Filter (IBF) policy statement recently released by the U.S. Federal Aviation Administration’s (FAA) Rotorcraft Directorate in Fort Worth, TX. This policy could change how IBFs are certified and may negatively impact future development of these important engine protection systems.

Donaldson Aerospace & Defense designs and manufacturers more than a dozen commercially certified and successfully fielded rotorcraft IBF systems. Donaldson has been developing IBF systems for the US military since 1998. Within the industry, IBFs have been in service with Supplemental Type Certificate (STC) approval for more than 20 years.

Arguably, IBFs are one of the most important safety innovations in the 80 year history of the helicopter. IBFs have made a positive impact on safety, availability and aircraft operating efficiencies by protecting rotorcraft turbine engines from degradation and catastrophic damage. IBF systems provide increased system safety with regard to the elimination of Foreign Object Damage (FOD), crew alerting and as an alternate air source of engine power recovery not available to an unprotected inlet operating in an austere environment.

The FAA has issued a proposed policy statement – Policy No. PS-ASW-37/29-7 – that relates to the installation of engine IBF systems and new regulatory guidance and compliance methods for obtaining an STC.

You can find a copy of the proposed policy statement as well as the format required for public comment at The comment period ends on 15 April 2016.

It is our belief that if not challenged and substantially modified, this policy statement may deter all current and future development of engine protecting IBFs, which will greatly limit options that rotorcraft owners have for protecting engines and reducing equipment maintenance costs.

The fact is that IBFs have been a substantial leap forward from the traditional Particle Separator/Inertial Separator systems. Limiting IBF use will be a step backward – and will reduce the options you have for protecting your helicopters.

Donaldson Aerospace & Defense has produced more than 4600 IBF systems that have accumulated an estimated 10 million flight hours with zero reported accidents. These statistics controvert the need for this proposed FAA policy statement.

IBFs and the associated science has benefitted helicopter owners and operators for more than two decades. OEMs and operators across the globe have relied on IBF technology for safety and long-term protection of their engines. That is a protection we believe you’ll want to retain for your current and future rotorcraft fleets.

We ask that you take a few moments to reply to the FAA during their comment period, which ends 15 April 2016.


Matt Fortuna
GM Aerospace & Defense
Aerospace Filtration System, Inc.
Donaldson Company, Inc.