NTSB Identification: LAX84FA095.
The docket is stored on NTSB microfiche number 23238.
Nonscheduled 14 CFR
Accident occurred Wednesday, December 07, 1983 in BLACK MOUNTAIN, NV
Aircraft: AEROSPATIALE AS 355F, registration: N57901
Injuries: 3 Fatal.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

THE HELICOPTER TOOKOFF ON AN AIR AMBULANCE FLT AT ABOUT 1219 PST. ACCORDING TO TOWER PERSONNEL, THE DEPARTURE APPEARED NORMAL. RADAR SERVICE WAS TERMINATED AT 1227 & THERE WAS NO FURTHER RADIO CONTACT WITH THE HELICOPTER. LATER, THE HELICOPTER WAS FOUND WHERE IT HAD CRASH LANDED ON STEEP MOUNTAINOUS TERRAIN, ROLLED OVER & BURNED. AN INVESTIGATION REVEALED AN OPEN LOGBOOK ENTRY THAT THE #1 TORQUE TRANSMITTER WAS INOP. A PERSON NEAR THE DEPARTURE POINT NOTICED THE L ENG COWLING WAS LOOSE. A SHORT TIME LATER, A 3' X 4' PIECE OF ENG COWLING WAS OBSERVED TO FALL FROM THE HELICOPTER. THERE WAS NO INDICATION IN THE AIRCREW'S RADIO TRANSMISSIONS THAT THEY WERE AWARE OF THE COWLING PROBLEM. AN EXAM REVEALED EVIDENCE THAT THE COWLING STANDOUT TUBE FOR THE L ENG HAD RUBBED AGAINST THE FREE WHEELING TURBINE GOVERNOR CABLE. AEROSPATIALE PSNL SAID THIS COULD DECREASE FUEL FLOW TO THE L ENG; AT HI POWER, THE R ENG GOVERNOR WOULD THEN INCREASE ITS FUEL FLOW & EXCEED LIMITS UNLESS PLT COMPENSATED. R FUEL SHUTOFF VALVE WAS FOUND NEAR ITS CLOSED POSITION.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

EMERGENCY PROCEDURE..IMPROPER..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

WRONG ENGINE SHUTDOWN..PERFORMED..PILOT IN COMMAND


Contributing Factors

TERRAIN CONDITION..MOUNTAINOUS/HILLY


Contributing Factors

ENGINE INSTRUMENTS,TORQUEMETER..INOPERATIVE


Contributing Factors

MAINTENANCE,REPLACEMENT..NOT PERFORMED


Contributing Factors

TERRAIN CONDITION..ROUGH/UNEVEN



Contributing Factors

COOLING SYSTEM,COWLING..UNDETERMINED


Contributing Factors

COOLING SYSTEM,COWLING..SEPARATION


Contributing Factors

TURBOSHAFT ENGINE,FREE TURBINE GOVERNOR..FALSE INDICATION

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