Skip to content

Atlas / STC / SA5490NM

FAA · Supplemental Type Certificate

STC SA5490NM

Installation of World Auxiliary Power Co. (WAPCO) mid passenger doorway airstair and FWD (L1) passenger doorway airstair, AFT stowage configuration.

Historical Reissued Aircraft Large Airplane Rev 12/11/2020 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

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