St. Louis, Missouri, February 24, 2008 – Aerospace Filtration Systems, Inc. (AFS) has marked an important milestone in helicopter engine protection with the delivery of more than 3,000 Inlet Barrier Filter (IBF) systems worldwide. The company manufactures industry-leading filtration solutions for a variety of commercial and military helicopter applications.

"AFS takes great pride in helping the many helicopter operators using our IBF's improve their engine protection and enhance their bottom line as well," stated AFS Director of Business Development Robert Stenberg. "Our team works hard to provide IBF technology that is readily integrated into airframes and has a positive long-term impact on commercial and military helicopter programs alike."

More than 3,000 AFS IBFs are in operation worldwide for a wide variety of commercial and military aircraft, with well over 1,000,000 total flight hours combined. AFS IBF's are protecting helicopter engines operating in military, air medical, firefighting, seismic/utility, corporate charter and various other mission types. While the ratio of military to commercial systems favors military, commercial operators are making significant gains and AFS is working hard to expand its product base. All customers are realizing the benefit of utilizing barrier filter technology for their engine inlet protection.

AFS President Michael Scimone sees a bright future for IBF's and the helicopter industry as a whole. "Our company is privileged to be part of this dynamic, growing industry and offer a popular product. It is always comforting to have happy customers; it makes all our engineering efforts worth it. AFS is fully committed to providing helicopter operators best in class inlet protection for years to come."

New development IBF systems for the Eurocopter EC 130, Bell 430 and AgustaWestland AW139 will achieve US FAA certification in 2008. AFS anticipates additional EASA certifications in 2008 as well, including the AgustaWestland AW119, Bell 205 and Eurocopter AS350.

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 offers 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), MD Helicopters MD 369 (MD 500H/D/E/F Series) and MD 900/902 Explorer. In addition a commercial type certified system for the new Bell 429 is nearing completion. Military IBF solutions are available for the new Bell ARH-70 Armed Reconnaissance Helicopter (ARH), Bell OH-58A/C Kiowa, Bell OH-58D Kiowa Warrior, UH-1H Huey, Sikorsky UH-60 Blackhawk main engine and APU, Boeing AH/MH-6J/M Little Bird, AH-64 Apache APU, and CH-47 Chinook APU. 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.

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