Air Plains Services Introduces Improved PMA Airbox Support Bracket  

Air Plains Services has gained Parts Manufacturer Approval (PMA) from the Federal Aviation Administration for an improved Cessna 172 airbox support bracket providing a tighter fit and longer service life than the original part.

“Our new, adjustable airbox bracket, developed after decades of experience replacing factory brackets, removes a lot of the stress that came from production variability,” said Shane O’Day, an Air Plains engineer. “If you’re replacing a damaged bracket or airbox, we think our new PMA bracket is going to be a great, lower-cost option for extending the life of the part.”

The bracket is approved for certain Cessna 172 L and M models as well as for all B through M models upgraded with the Air Plains 180hp Lycoming O-360 engine (STC SA4428SW). Air Plains bracket part number APS0552120-2 replaces either 0552120-2 or 0552120-1 and fits all approved models.

O’Day said the common issue with factory brackets is a variation in bracket height – as much as one-quarter inch from bracket to bracket – sometimes resulting in a poor fit of the bracket and airbox to the engine. The poor fit, coupled with common engine vibration, increases stress, and ultimately causes cracks in the assembly components.

Air Plains has incorporated two innovative features into its new FAA PMA bracket:

  • The new PMA bracket is adjustable during installation which compensates for any misalignment in height;
  • The Air Plains bracket features a steel upper bracket, improving the strength where it matters most.


Air Plains is also developing similar adjustable PMA brackets for other Cessna single-engine piston models. The airbox bracket is available at the Air Plains Services online store, along with a variety of new PMA and like-new airboxes as well as new PMA airbox gaskets, all at competitive prices.

For more information about the new PMA bracket (including model eligibility) or any of Air Plains other products or services, call 1-800-752-8481 or +1-620-326-8904, or visit

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