WELLINGTON, KS (Aug. 8, 2025) – Air Plains Services, a world leader in general aviation engine and avionics upgrades, announced today it has gained Parts Manufacturing Approval from the Federal Aviation Administration for the airbox filter seal assembly for Cessna 172 L and M model aircraft.
“The seal assembly is an important part of the cooling system and plays a key role in proper CHT management,” said Katie Church, president of Air Plains. “We specialize in PMA parts for Cessna piston, particularly the cooling system, and when we find ways to improve on an original design, we want to add it our product range.”
Mechanics at Air Plains report the absence of the filter seal assembly on many L and M model Cessna 172 Skyhawks coming in for engine upgrades. This can cause a change in designed air flow over the engine, resulting in higher CHTs, as much as 10 to 15 degrees F.
“The seal is essential to achieve a greater pressure differential in the engine compartment that strengthens the flow of cooler air over the engine,” Church said. “As we’ve done with other components such as the airbox, we’ve made it better, easy to install and less expensive than other options.”
Air Plains opted for a special, lightweight polycarbonate plastic due to its higher temperature resistance, weight and strength. The fiberglass-reinforced silicone material is a single piece seal that provides the best differential pressure between the upper and lower cowl and is designed for easy installation.
Air Plains offers a wide range of PMA parts for the induction system including airboxes, collars, gaskets, adjustable brackets and baffles assemblies, all available at the company’s online store.
For information about the new airbox filter seal assembly or any Air Plains product, call 1-800-752-8481 or +1-620-326-8904 or send an email to sales@airplains.com.
