Individually Owned: 151,845
Corporate Owned: 143,699
Aircraft Accident/Incident Report
Jackson, California 95642
Wednesday, August 5, 1998 10:20 PDT
NTSB Narrative Summary Released at Completion of Accident
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.
NTSB Probable Cause Narrative
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.
Event Information
| Type of Event | Accident |
| Event Date | 8/5/1998 |
| Event Day of the Week | Wednesday |
| Time of Event | 1020 |
| Event Time Zone | Pacific Daylight Time |
| Event City | JACKSON |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 95642 |
| Event Date Year | 1998 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | |
| Event Location Nearest Airport ID | |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1647 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 35 |
| Weather Observation Facility ID | TVL |
| Elevation of weather observation facility | 6264 |
| Distance of event from weather observation facility (units?) | 98 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 40 |
| Air Temperature at event time (in degrees celsius) | 24 |
| Dew Point at event time (in degress fahrenheit) | -1 |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Calm |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1836 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Aug 5 1998 12:00AM |
| NTSB Notification Time | 1719 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 11 2000 11:42AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N151MT |
| NTSB Number | LAX98LA258 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | M. C. Thomas |
| Aircraft Model | STEWART S-51 |
| Aircraft Series Identifier | STEWART S- |
| Aircraft Serial Number | S-51D |
| Certified Max Gross Weight | 3500 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | Yes |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | 62 |
| Airframe Hours | 62 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | M.C. THOMAS CONTSTRUCTION CO. |
| Aircraft Owner Street Address | P.O. BOX 1513 |
| Aircraft Owner City | ARROYO GRANDE |
| Aircraft Owner State | CA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 93421 |
| Operator is an individual? | -- |
| Operator Name | MICHAEL W. CLIPPERTON |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 15743 M STEET |
| Operator City | MOJAVE |
| Operator State | CA |
| Operator Country | |
| Operator Zip code | 93501 |
| Operator Code | |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | RNO |
| Departure City | RENO |
| Departure State | NV |
| Departure Country | |
| Departure Time | 945 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | SBP |
| Destination City | SAN LUIS OBISPO |
| Destination State | CA |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:34AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |