M C Thomas STEWART S-51 N151MT
5 August 1998 · Jackson, California, United States · No injuries
Summary
On 5 August 1998 at about 17:20 local time, a M C Thomas STEWART S-51 registered N151MT, operated by Michael W. Clipperton, was involved in an accident near Jackson, California, 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 17:20
- Classification
- Accident
- Location
- Jackson, California, United States
- Coordinates
- 38.3494, -120.7705
- Aircraft
- M C Thomas STEWART S-51
- Registration
- N151MT
- Category
- Airplane
- Engines
- 1
- Operator
- Michael W. Clipperton
- Operating rule
- Part 91: General Aviation
- Purpose of flight
- Personal
- Phase of flight
- Not recorded
- Route
- Reno → San Luis Obispo
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Day
- NTSB number
- LAX98LA258
People
Nobody was injured.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 1 | 0 | 0 | 0 | 1 |
Probable cause
Failure of the propeller governor pulley drive shaft due to a modification made to the system by the owner that included welding a retaining pin to the center of the heat treated drive shaft, which compromised the shaft's design strength margin.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
While en route to the destination airport, the airplane experienced a loss of engine power. The pilot made a forced landing on a highway and collided with a snow pole. The airplane veered off of the road and came to rest after it collided with a tree. The owner/builder stated that he had modified the drive shaft from the original 'V' belt drive to a dual 'serpentine' belt/pulley system. He further stated that in order to install the new belt/pulley system, he had to weld a retaining pin in the center of the original drive shaft. The propeller governor pulley was found at the bottom of the engine compartment and the shaft was found to have separated at the center point. The drive shaft exhibited a bluing and discoloration at the center where the owner had welded it on the pin. It was noted that the original manufacturer of the propeller governor drive shaft had placed a heat treat stamp on the shaft.
Quoted verbatim from the NTSB record.
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 1 Oct 1998 | Cessna 152 | Avalon, California, United States | Orange County Flight Center | Fatal | 1 |
| 5 Oct 1998 | Grumman TS-2A | Banning, California, United States | - | Fatal | 1 |
| 15 Aug 1998 | North American NAVION | Salinas, California, United States | - | Fatal | 2 |
| 21 Aug 1998 | Bell 206B | Salinas, California, United States | - | No injuries | - |
| 21 Aug 1998 | Robinson R22B | Ramona, California, United States | Civic Helicopters | No injuries | - |
| 27 Aug 1998 | Aerospatiale SA316B | Porterville, California, United States | U.s. Dept. of the Interior | No injuries | - |