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Atlas / STC / SA4-1121

FAA · Supplemental Type Certificate

STC SA4-1121

Increase in allowable gross weight from 2850 to 3100 pounds per STC SA4-915 when equipped with 20 gallon wing-tip tanks (Brittain Aircraft P/N 1000) installed.

Historical Reissued Aircraft Single-Engine Rev 03/01/2016 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 ↗