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Atlas / STC / SA20GL

FAA · Supplemental Type Certificate

STC SA20GL

Installation of Woodward Type II electronic propeller synchronizer or synchrophaser system. (G-44A MODIFIED COLEMILL - STC 2-13) (500-A modified - Colemill STC SA340SO)

Historical Reissued Aircraft Small Multi-Engine Rev 06/17/2005 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 (93)

+ 43 more aircraft

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 ↗