St. Louis, Missouri, December 26, 2007 – Aerospace Filtration Systems, Inc. (AFS) has received a Supplemental Type Certificate (STC) from the European Aviation Safety Agency (EASA) for an Inlet Barrier Filter (IBF) system for Bell 206B JetRanger series helicopters. European operators can now maximize engine protection while realizing performance and maintenance benefits from proven AFS technology and innovation.

As a result of the STC application AFS IBF-equipped Bell 206B helicopters can freely operate with no engine inlet imposed flight or gross weight restrictions. The FAA approved AFS Flight Manual Supplement (FMS) allows operation to basic inlet performance charts based on power check results. Operators routinely experience significant temperature reductions resulting in improved aircraft performance. With Bell's required snow induction kit installed, the IBF allows flight in falling or blowing snow without restrictions.

The IBF system for the Bell 206B features two flat filter assemblies, easily removed in the field via an access panel, without cowl removal. AFS incorporates an integral bypass design, and the IBF system is readily mounted within the existing Bell cowling utilizing FOD screen or EAPS mounting provisions. A filter maintenance aid allows for on-condition status checks between established cleaning intervals, eliminating unnecessary service.

About Aerospace Filtration Systems, Inc.
AFS is the industry leader in the design, development and manufacture of high-performance engine IBF systems for commercial and military propulsion systems. The company manufactures certified IBF solutions for the Eurocopter AS350 B/BA/B1/B2/B3 (AS350D/SD/SD2-Soloy STC), AgustaWestland AW119 Koala, Bell 205A1, 206B, 407, 206L-3/4, 206L-1(C30) and MD Helicopters MD 369 (MD 500H/D/E/F Series). IBF systems for the Eurocopter EC 130, MD 900/902 Explorer, Bell 430 and AgustaWestland AW139 are in development. AFS is a wholly owned subsidiary of the Donaldson Company, Inc. Traded on the NYSE under the symbol DCI, Donaldson is a member of the S&P MidCap 400 Index. Additional company information for AFS and DCI is available at www.afsfilters.com and www.donaldson.com.

Visit AFS at Booth 4013 during the upcoming HELI-EXPO 2008 in Houston, Tex., February 24-26, 2007.

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For more information, contact:
Aerospace Filtration Systems, Inc.
Sales and Marketing
(636) 300-5200
sales@afsfilters.com
www.afsfilters.com