STC ST709SO-D

Installation of flight spares container in right hand main landing gear wheel well on fuselage station 960 bulkhead. (707-321B)

Current Reissued Aircraft Large Multi-Engine Rev 09/11/1978 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.

Applicable aircraft (1)

4A26 The Boeing Company · 707

Certification basis — 14 CFR

Part 21

Specific sections

§ 21.111
§ 21.113
§ 21.115
§ 21.117
§ 21.119
§ 21.120

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