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Atlas / STC / SA12225AC

FAA · Supplemental Type Certificate

STC SA12225AC

This STC will incorporate P&W 1700 rpm propeller reduction gearbox on P&WC engines to allow Hartzell HC-B5MP-3( ), propeller installation

Current Amended Engine Rev 12/09/2025 View PDF on drs.faa.gov ↗

What is an STC?

A Supplemental Type Certificate authorizes a major modification or alteration to an FAA-certificated aircraft. STCs are how operators legally install new avionics, change fuel systems, add floats, swap engines, etc. — every change beyond a minor modification needs one.

The STC PDF on drs.faa.gov is the authoritative document — it lists installation instructions, ICA requirements, and any limitations. Open PDF ↗