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Atlas / STC / SH178WE

FAA · Supplemental Type Certificate

STC SH178WE

Installation of Allison 250-C20/250-C20B engine and related changes. (UH-12E-L (4 place))

Current Reissued Aircraft Rotorcraft Rev 08/19/2005 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 (2)

Certification basis — 14 CFR

Specific sections

  • Sec. 111
  • Sec. 113
  • Sec. 115
  • Sec. 117
  • Sec. 119
  • Sec. 120
  • § 21.47
  • Sec. 27.46
  • Sec. 27.47
  • Sec. 27.48
  • § 27.49
  • Sec. 27.50
  • § 27.51
  • Sec. 27.52
  • Sec. 27.53
  • Sec. 27.54
  • Sec. 27.55
  • Sec. 27.56
  • Sec. 27.57
  • Sec. 27.58
  • Sec. 27.59
  • Sec. 27.60
  • Sec. 27.61
  • Sec. 27.62
  • Sec. 27.63
  • Sec. 27.64
  • § 27.65
  • Sec. 27.66
  • § 27.67
  • Sec. 27.68

The STC PDF on drs.faa.gov is the authoritative document — it lists installation instructions, ICA requirements, and any limitations. Open PDF ↗