Aerospatiale SA316B N83776
20 August 1990 · Meeteetse, Wyoming, United States · Serious injuries
Summary
On 20 August 1990 at about 00:00 local time, a Aerospatiale SA316B registered N83776, operated by Rocky Mountain Helicopter, was involved in an accident near Meeteetse, Wyoming, United States. 7 people were on board and 3 were seriously injured, 4 had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 00:00
- Classification
- Accident
- Location
- Meeteetse, Wyoming, United States
- Coordinates
- 44.1506, -108.8693
- Aircraft
- Aerospatiale SA316B
- Registration
- N83776
- Category
- Helicopter
- Engines
- 1
- Operator
- Rocky Mountain Helicopter
- Operating rule
- Part 135: Air Taxi & Commuter
- Purpose of flight
- Unknown
- Phase of flight
- Not recorded
- Aircraft damage
- Destroyed
- Weather
- VMC
- Light
- Day
- NTSB number
- DEN90FA172
People
3 people were seriously injured.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 7 | 0 | 3 | 4 | 0 |
Probable cause
A MAIN ROTOR HEAD BLADE DAMPENER FAILURE. A FACTOR IN THE ACCIDENT WAS THE SUBSEQUENT FAILURE OF A BLADE RESTRAINING CABLE.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
APPROXIMATELY 2 MINUTES INTO THE FLIGHT, THE PILOT EXPERIENCED A SLIGHT 1 TO 1 VIBRATION THROUGH THE CYCLIC. THIS TYPE VIBRATION IS ASSOCIATED WITH MAIN ROTOR DAMPERS AND THE PILOT 'STIRRED' THE CYCLIC IN AN EFFORT TO PURGE AIR OUT OF THE BLADE DAMPERS. THIS ELIMINATED THE PROBLEM, HOWEVER, IT RECURRED AND COULD NOT BE ELIMINATED. THE VIBRATION INCREASED TO THE POINT OF LOSS OF CONTROL. AN EMERGENCY LANDING WAS ATTEMPTED WITH TOUCHDOWN OCCURRING AT ABOUT 60 KNOTS. THE HELICOPTER CAME TO REST INVERTED AND WAS LARGELY CONSUMED BY POST-IMPACT FIRE. METALLURGICAL ANALYSIS ON A FAILED BLADE RESTRAINING CABLE REVEALED A CATASTROPHIC FAILURE IN A LOW CYCLE FATIGUE MODE CONSISTENT WITH A SECONDARY CAUSE, AND DUE TO SHORT TERM VIBRATIONS. IN ADDITION TO FATIGUE, THERE WAS EVIDENCE OF PLASTIC DEFORMATION DUE TO VIBRATORY LOADS FROM THE DAMPER SYSTEMS. FIRE DAMAGE PREVENTED ADDITIONAL FAILURE ANALYSIS.
Quoted verbatim from the NTSB record.
Other Aerospatiale SA316B accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 3 Dec 1990 | Aerospatiale SA316B | Vernal, Utah, United States | Avman Aviation Helicopter SVC | Minor injuries | - |
| 28 Nov 1989 | Aerospatiale SA316B | Park City, Utah, United States | - | Fatal | 1 |
| 2 Apr 1988 | Aerospatiale SA316B | Silver Plume, Colorado, United States | - | No injuries | - |
| 4 Jul 1993 | Aerospatiale SA316B | Snyder, Texas, United States | Geo-Seis Helicopters, Inc | Serious injuries | - |
| 19 Jul 1987 | Aerospatiale SA316B | Red Lodge, Montana, United States | Pegasus Helicopters, Inc. | No injuries | - |
| 1 Apr 1993 | Aerospatiale SA316B | Aspen, Colorado, United States | Sea Pacific, Inc. | Fatal | 3 |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 4 Jun 1990 | Piper PA-18-150 | Douglas, Wyoming, United States | Norman Ranch Company | No injuries | - |
| 24 Jun 1990 | Beechcraft 23 | Wheatland, Wyoming, United States | Mike Koogle | No injuries | - |
| 18 Dec 1990 | Piper PA-31-350 | Evanston, Wyoming, United States | Alpine Aviation | Fatal | 1 |
| 14 Jul 1990 | Mooney M20F | Torrington, Wyoming, United States | B & L Aviation, Inc. | No injuries | - |
| 28 Jul 1990 | Gulfstream G-II | Cheyenne, Wyoming, United States | Martin Marietta Corporation | Serious injuries | - |
| 27 Jul 1990 | Lake LA-250 | Rawlins, Wyoming, United States | - | Minor injuries | - |