FAA · Supplemental Type Certificate
STC SR12148LA
Installation of modified configurations of the Bell Helicopter Textron (BHT) Model 412 “Arm and Bearing Assembly”
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 (2)
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 ↗