Aerospatiale AS 355F accident near Black Mountain, Nevada, December 7, 1983
On December 7, 1983 at about 8:29 pm local time, a Aerospatiale AS 355F (helicopter), registered N57901, was destroyed in an accident near Black Mountain, Nevada. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 3 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 7, 1983 · about 8:29 pm local time
- Place
- Black Mountain, Nevada · map
- Type
- Accident
- Injuries
- 3 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS 355F · all AS 355Fs on the register
- Registration
- N57901 · no longer on the register · serial AS-355F
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
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 complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: instructor: airplane multi-engine; instrument: helicopter; rotorcraft: helicopter
- Flight time: 5,300 hours in all; 400 in this make and model; 90 in the last 90 days; 30 in the last 30 days; 5,200 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 961 hours
- Last inspection: annual inspection, December 6, 1983; 2 hours since
- Maximum gross weight: 5,070 lb
- Seats: 3
- Landing gear: fixed
- Engine: Allison 250-C20F (turboshaft); 0 hours total
The flight
- Departed from: NV53 Las Vegas NV at 8:19 pm
- Destination: Needles CA
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 75 statute miles
- Sky: overcast at 25,000 ft; not recorded at 25,000 ft
- Temperature: 48°F (9°C), dew point 18°F (-8°C)
- Altimeter: 30.00 inHg
- Observation at 3:49 am from LAS
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.