Type Certificate Data Sheet Al2EA. Refer to: FAA APPROVED Gulfstream. Aerospace Corp. (GAC) recommended Aircraft Service Change (ASC) No.. 170 sub: AIR-CONDITIONING (ATA-21), Cockpit/Cabin Temperature sensor power source-rebus, dated March 30, 1990;. GAC G-IV Wiring Diagram -Manual drawing 1159AV40103, DC POWER