FAA · Supplemental Type Certificate
STC SA01956AT-D
Installation of replacement fuel cell assemblies
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 (27)
- 2A4 Twin Commander Aircraft Corporation · 680
- 2A4 Twin Commander Aircraft Corporation · 680-E
- 2A4 Twin Commander Aircraft Corporation · 680-F
- 2A4 Twin Commander Aircraft Corporation · 680-FL
- 2A4 Twin Commander Aircraft Corporation · 680-FL(P)
- 2A4 Twin Commander Aircraft Corporation · 680-F(P)
- 2A4 Twin Commander Aircraft Corporation · 680-T
- 2A4 Twin Commander Aircraft Corporation · 680-V
- 2A4 Twin Commander Aircraft Corporation · 680-W
- 2A4 Twin Commander Aircraft Corporation · 681
- 2A4 Twin Commander Aircraft Corporation · 685
- 2A4 Twin Commander Aircraft Corporation · 690
- 2A4 Twin Commander Aircraft Corporation · 690C
- 2A4 Twin Commander Aircraft Corporation · 690D
- 2A4 Twin Commander Aircraft Corporation · 695
- 2A4 Twin Commander Aircraft Corporation · 695A
- 2A4 Twin Commander Aircraft Corporation · 695B
- 2A4 Twin Commander Aircraft Corporation · 720
- 6A1 Twin Commander Aircraft Corporation · 500
- 6A1 Twin CommanderAircraft Corporation · 500-A
- 6A1 Twin Commander Aircraft Corporation · 500-B
- 6A1 Twin Commander Aircraft Corporation · 500-S
- 6A1 Twin Commander Aircraft Corporation · 500-U
- 6A1 Twin Commander Aircraft Corporation · 520
- 6A1 Twin Commander Aircraft Corporation · 560
- 6A1 Twin Commander Aircraft Corporation · 560-A
- 6A1 Twin Commander Aircraft Corporation · 560-E
Specific sections
- Sec. 111
- Sec. 113
- Sec. 115
- Sec. 117
- Sec. 119
- Sec. 120
- § 21.47
The STC PDF on drs.faa.gov is the authoritative document — it lists installation instructions, ICA requirements, and any limitations. Open PDF ↗