Individually Owned: 150,657
Corporate Owned: 137,281
San Luis Obispo Airport
Aircraft Accident/Incident Report
San Luis Obispo, California 93401
Saturday, July 10, 1999 12:30 PDT
NTSB Narrative Summary Released at Completion of Accident
The instructor said that the power came up smoothly on the takeoff roll, but that the engine suddenly quit at 600 feet agl. The flight instructor took the controls, lined up on a major interstate highway, and touched down in the northbound lanes. The right wing struck a bush, which spun the airplane off the highway and down the embankment next to the highway. An engine teardown disclosed that the crankshaft idler gear (left magneto) was detached from the mounting pad at the back of the crankcase. The crankshaft gear was not secured to the crankshaft, and the locating dowel pin was fractured and separated. Further examination of the idler gear shaft and attaching parts revealed severe wear signatures on the attachment bolts and locking plate, and the bolts displayed signatures consistent with prolonged contact with the rotating idler gear. The bore at the idler gear shaft-mounting pad was also severely worn and elongated. The crankshaft counterbore and corresponding gear revealed fretting and corrosion signatures at the mating surfaces, and the dowel pin was separated in line with the parting surfaces of the gear and counterbore. The dowel pin fracture surface displayed fatigue. A propeller overhaul was completed 20 hours prior to the accident. The Hartzell propeller manual prohibits balance weights in excess of 0.9 ounces (25.51 grams) in any one location on the spinner. Weights totaling 36 grams were found on one location on the airplane spinner.
NTSB Probable Cause Narrative
The failure/separation of the crankshaft idler gear and the fatigue failure and subsequent separation of the crankshaft dowel pin due to the improper static and dynamic balance of the propeller by maintenance personnel.
Event Information
| Type of Event | Accident |
| Event Date | 7/10/1999 |
| Event Day of the Week | Saturday |
| Time of Event | 1230 |
| Event Time Zone | Pacific Daylight Time |
| Event City | SAN LUIS OBISPO |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93401 |
| Event Date Year | 1999 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | SAN LUIS OBISPO |
| Event Location Nearest Airport ID | KSBP |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 3 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 209 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1230 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 110 |
| Weather Observation Facility ID | SBP |
| Elevation of weather observation facility | 209 |
| Distance of event from weather observation facility (units?) | 3 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 20000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 27 |
| Dew Point at event time (in degress fahrenheit) | 14 |
| Wind Direction (degrees magnetic) | 270 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | Unknown |
| 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 | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1702 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 10 1999 12:00AM |
| NTSB Notification Time | 1330 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Aug 14 2001 2:55PM |
| User who most recently changed record | MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N6597P |
| NTSB Number | LAX99LA248 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Piper |
| Aircraft Model | PA-24-180 |
| Aircraft Series Identifier | PA-24-180 |
| Aircraft Serial Number | 24-1719 |
| Certified Max Gross Weight | 2550 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | May 1 1999 12:00AM |
| Airframe hours since last inspection | 20 |
| Airframe Hours | 4799 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | J. L. FERRELL JR. |
| Aircraft Owner Street Address | 28173 ALAMINOS DRIVE |
| Aircraft Owner City | SAUGUS |
| Aircraft Owner State | CA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 91350 |
| Operator is an individual? | -- |
| Operator Name | |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | |
| Operator City | |
| Operator State | |
| Operator Country | |
| Operator Zip code | |
| 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) | Instructional |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | KWHP |
| Departure City | PACOIMA |
| Departure State | CA |
| Departure Country | |
| Departure Time | 1030 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Takeoff |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 14 2001 10:24AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 29 |
| Runway Length | 4799 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |