# Accident 19980805019749A: Amtr STEWARTS51, Jackson, CA, August 5, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: August 5, 1998, 10:20 local time
- Place: Jackson, CA
- Damage: Substantial damage
- Phase of flight: Fcd/Prec Ldg From Cruise
- Operating rules: General operating rules (Part 91)
- Location: 38.3494° N, 120.7705° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=38.3494&lon=-120.7705&mi=10
- Aircraft: N151MT, a cancelled registration (https://openairdocs.org/deregistered/N151MT-1998-09-25) (OpenAirDocs)
- Registry model: M C Thomas Const STEWART S-51 (registry code 05605Q4, https://openairdocs.org/model/m-c-thomas-const-stewart-s-51) (OpenAirDocs)
- Reported make and model: AMTR STEWARTS51
- People aboard: 1
- Fatal injuries: 0
- Pilot flight hours: 335 total, 26 in this make and model, 49 in the last 90 days
- NTSB investigation: [NTSB LAX98LA258](https://openairdocs.org/ntsb/LAX98LA258) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19980805019749A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

ACFT EXPERIENCED ENGINE FAILURE, LOST ALL POWER AND MADE AN EMERGENCY LANDING ON HIGHWAY 88, ON LANDING, THE ACFT RAN OFF THE HIGHWAY AND STRUCK A TREE. (.4) 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.                                                                                                                            (-23) AUGUST 5, 1998 10:20 AM, EXPERIMENTAL AMATEUR-BUILT (P-51 REPLICA N151MT) HAD A FORCED LANDING ON HIGHWAY 88, 20 MILES EAST OF JACKSON, CA. NO INJURIES REPORTED BY PILOT (ONLY SOLE ON BOARD) OR GROUND PERSONNEL. AIRCRAFT WAS SUBSTANTIALLY DAMAGED. PROPELLER GOVERNOR DRIVE SHAFT HAD FAILED IN AN AREA THAT HAD BEEN MODIFIED BY THE AMATEUR BUILDERS. THE DRIVE SHAFT FELL OUT OF THE ENGINE, AND OIL PRESSURE WAS LOST.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX98LA258](https://openairdocs.org/ntsb/LAX98LA258), Aug 5, 1998: M. C. Thomas Stewart S-51 (N151MT), Jackson, CA, substantial damage. 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…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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