FAA · Supplemental Type Certificate
STC SA931NW
Installation of Hayes Industries tapered axles to accommodate Hayes 27 inch wheel assemblies (PN G31A), Hayes 11 x 2 brake assembly (PN H-12-19), Warner Aircraft brake master cylinders (PN 3150-5) and associated tires and plumbing
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)
Certification basis — 14 CFR
Specific sections
- Sec. 111
- Sec. 113
- Sec. 115
- Sec. 117
- Sec. 119
- Sec. 120
The STC PDF on drs.faa.gov is the authoritative document — it lists installation instructions, ICA requirements, and any limitations. Open PDF ↗