FAA · Supplemental Type Certificate
STC SH1599SO
Removal of main transmission oil cooler blower and associated parts.
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 (10)
- 1H4 Sikorsky Aircraft Corporation · S-55B
- 1H4 Sikorsky Aircraft Corporation · S-55
- HR1SO Sikorsky Aircraft Corporation · HRS-1/CH-19
- HR1SO Sikorsky Aircraft Corporation · H-19G
- HR1SO Sikorsky Aircraft Corporation · H-19D
- HR1SO Sikorsky Aircraft Corporation · CH-19E
- HR1SO Sikorsky Aircraft Corporation · UH-19C
- HR1SO Sikorsky Aircraft Corporation · YH-19A
- HR1SO Sikorsky Aircraft Corporation · H-19A
- HR1SO Sikorsky Aircraft Corporation · HRS-3/H-19B
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 ↗