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Atlas / STC / ST09524SC

FAA · Supplemental Type Certificate

STC ST09524SC

Piper conversion of air conditioning systems from using R12 to R134a refrigerant on aircraft models listed. For PA-31-300 s/n 31-660, 31-712 thru 31-900, 31-7300901& up. For PA-31-325 sns 31-7400990 & up. PA-31-350 sns, 31-5001& 31-5003, 31-7305005 up

Current Amended Aircraft Single-Engine Rev 03/28/2000 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 (25)

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 ↗