San Joaquin OH-58A+ N177SJ
10 August 2005 · Lancaster, California, United States · Fatal
Summary
On 10 August 2005 at about 13:00 local time, a San Joaquin OH-58A+ registered N177SJ was involved in an accident near Lancaster, California, United States. One person was on board and one died. 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 13:00
- Classification
- Accident
- Location
- Lancaster, California, United States
- Coordinates
- 34.7078, -118.0325
- Aircraft
- San Joaquin OH-58A+
- Registration
- N177SJ
- Category
- Helicopter
- Engines
- 1
- Operator
- Not recorded
- Operating rule
- Part 137: Agricultural
- Purpose of flight
- Aerial Application
- Phase of flight
- Not recorded
- Route
- Lancaster → Lancaster
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Dawn
- NTSB number
- LAX05FA264
People
1 person died.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 1 | 1 | 0 | 0 | 0 |
Probable cause
The pinion to turbine shaft coupling failed in fatigue due to a misaligned turbine shaft, which resulted in a loss of engine power.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
Following a loss of engine power, the helicopter impacted the ground during the application of chemicals to an agricultural field. Post accident examination of the engine showed that the power turbine to pinion gear coupling had fractured. Metallurgical examination of the affected components showed that the coupling failed in fatigue, which effectively separated the engine from the main rotor gearbox. The fatigue was the result of a misaligned power turbine outer shaft, where the axis of the turbine shaft was angled slightly relative to the coupling and pinion axes. The turbine section had been removed from another engine due to metal contamination. The turbine section was repaired and subsequently installed on the accident helicopter on August 11, 2004, where it operated for 770.3 hours prior to the accident. Weight and balance calculations showed that the helicopter was in excess of its certificated maximum gross weight by 174 pounds.
Quoted verbatim from the NTSB record.
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 28 May 2005 | Robinson R44 | Lucerne Valley, California, United States | - | Serious injuries | - |
| 28 May 2005 | S A Centrair PEGASE 101D | Williams, California, United States | - | No injuries | - |
| 30 May 2005 | Cessna 172N | Stockton, California, United States | Luis Rivara | No injuries | - |
| 27 Dec 2005 | Socata TBM 700 | Lancaster, California, United States | - | Minor injuries | - |
| 28 Dec 2005 | Learjet 35A | Truckee, California, United States | - | Fatal | 2 |
| 8 Sep 2005 | Robinson R22 | Santa Clarita, California, United States | Orbic Helicopters | No injuries | - |