SEA87IA084

Factual narrative

APRX 422 FLT HRS BFR THE FLT, THE SMITH AEROSTAR 601P WAS MODIFIED IAW MACHEN STC SA980NW. DRG LEVEL OFF AT 16,500' MSL,BLISTERING & DISCOLORATION WERE NOTED ON THE #1 ENG NACELLE. THE PLT SHUT DOWN & FEATHERED THE #1 ENG, THEN RETURNED TO THE DEPARTURE ARPT & LANDED WITHOUT FURTHER INCIDENT. AFTER LNDG, AN EXAM REVEALED AN IN-FLT FIRE HAD OCCURRED, WHICH RESULTED IN MINOR DMG OF THE ENG ACCESSORY SECTION. TWO EXHAUST CLAMPS WERE FOUND LOOSE AT THE EXHAUST STACK WASTE GATE CONNECTION. HOT GASES FROM THE LOOSE CONNECTION HAD ESCAPED & IMPINGED ON THE TURBOCHARGER OIL SUPPLY HOSE (MACHEN PN CAA04S160). THE HOSE WAS WIRE REINFORCED & FIRE SLEEVED, BUT WAS LOCATED CLOSE TO THE EXHAUST STACK. THERE WAS EVIDENCE THAT IT HAD RUPTURED FROM PROLONGED EXPOSURE TO HEAT. ESCAPING OIL FROM THE HOSE CAME IN CONTACT WITH THE HOT EXHAUST STACK & TURBOCHARGER, WHICH RESULTED IN A FIRE. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12