Sikorsky S-58BT N439DS
16 July 1990 · Ovando, Montana, United States · No injuries
Summary
On 16 July 1990 at about 16:30 local time, a Sikorsky S-58BT registered N439DS, operated by Skyline Helicopters, was involved in an accident near Ovando, Montana, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 16:30
- Classification
- Accident
- Location
- Ovando, Montana, United States
- Coordinates
- 47.0693, -113.0405
- Aircraft
- Sikorsky S-58BT
- Registration
- N439DS
- Category
- Helicopter
- Engines
- 2
- Operator
- Skyline Helicopters
- Operating rule
- Part 133: Rotorcraft Ext. Load
- Purpose of flight
- Other Work Use
- Phase of flight
- Not recorded
- Route
- Canyon Creek → Unknown
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Day
- NTSB number
- SEA90LA137
People
Nobody was injured.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 1 | 0 | 0 | 0 | 1 |
Probable cause
THE PILOT DID NOT MAINTAIN ROTOR RPM AFTER A COMPRESSOR ASSEMBLY BLADE FAILURE. A RELATED FACTOR WAS AN INADEQUATE AUTOROTATION RESULTING IN A HARD LANDING.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
DURING AN EXTERNAL LOAD LOGGING OPERATION, THE PILOT HAD JUST TAKEN OFF FROM REFUELING AND WAS PREPARING FOR ANOTHER LOAD PICK- UP WHEN THE NUMBER ONE ENGINE LOST POWER AND FLAMES WERE OBSERVED SHOTTING OUT FROM THE EXHAUST. THE PILOT TRIED TO FLY THE HELICOPTER ON ONE ENGINE TO A LANDING AREA, HOWEVER, RPM WAS DROPPING. THE PILOT INITIATED AN AUTOROTATION WHICH RESULTED IN A HARD LANDING.
Quoted verbatim from the NTSB record.
Other Sikorsky S-58BT accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 13 Jul 1988 | Sikorsky S-58BT | Marina del Rey, California, United States | Aris Helicopters, Ltd | Serious injuries | - |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 2 Apr 1990 | Peterson KIT FOX MODEL 1 | Highwood, Montana, United States | - | No injuries | - |
| 21 Mar 1990 | Cessna 172M | Three Forks, Montana, United States | - | No injuries | - |
| 8 Apr 1990 | Piper PA-28-140 | Forsyth, Montana, United States | - | Serious injuries | - |
| 18 Apr 1990 | Cessna 172 | Columbia Falls, Montana, United States | Eagle Aviation, Inc. | No injuries | - |
| 6 May 1990 | Cessna C-180E | Helena, Montana, United States | - | No injuries | - |
| 10 May 1990 | Piper PA-18-150 | Powderville, Montana, United States | W.l. Ranch Co. | No injuries | - |