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Atlas / STC / SE31WE

FAA · Supplemental Type Certificate

STC SE31WE

Installation of Electro-Coatings, Inc. piston rings P/N 251822, 251824, and 251825 on Pratt and Whitney R-985 piston P/N 27056 for use with Channelcromium plated R-985 engine cylinders

Current Reissued Engine Rev 10/31/2016 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.

Certification basis — 14 CFR

Specific sections

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