Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Spanish Fork, Utah 84660
Saturday, July 1, 2000 13:00 MDT
NTSB Narrative Summary Released at Completion of Accident
The pilot had just departed on a cross-country flight, and had climbed to 9,500 feet. He said that he began to feel a 'heavy vibration' in the aircraft, and immediately turned towards the closest runway. Soon thereafter the propeller separated from the airplane, and the pilot performed a forced landing without further incident. Postincident examination of the maintenance records indicated that the attachment bolts for the wooden propeller were last torqued 110 hours before the incident. The manufacturer of the propeller recommends that their wooden propellers be torque checked every 50 hours of flight. Examination revealed that the propeller attachment bolts showed signs of fatigue failure. There was also fretting damage on the propeller extension flange and bushing shanks. The above-mentioned signatures are suggestive of the studs being insufficiently torqued by the mechanic during assembly or periodic maintenance procedures not being followed, and subsequently becoming loose during propeller operation.
NTSB Probable Cause Narrative
The company maintenance personnel's inadequate torquing procedures of the propeller attachment bolts which resulted in the fatigue failure of the propeller attachment bolts and the in-flight separation of the propeller.
Event Information
| Type of Event | Incident |
| Event Date | 7/1/2000 |
| Event Day of the Week | Saturday |
| Time of Event | 1300 |
| Event Time Zone | Mountain Daylight Time |
| Event City | SPANISH FORK |
| Event State | UTAH |
| Event Country | -- |
| Zipcode of the event site | 84660 |
| Event Date Year | 2000 |
| Event Date Month | 7 |
| 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 | 4529 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Pilot |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| 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) | 10 |
| Air Temperature at event time (in degrees celsius) | 29 |
| Dew Point at event time (in degress fahrenheit) | 4 |
| Wind Direction (degrees magnetic) | 200 |
| 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) | 5011 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 3 2000 12:00AM |
| NTSB Notification Time | 819 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Apr 21 2001 4:04AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N991CT |
| NTSB Number | DEN00IA133 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Diamond Aircraft Industries |
| Aircraft Model | 20C-1 |
| Aircraft Series Identifier | 20C-1 |
| Aircraft Serial Number | C0091 |
| Certified Max Gross Weight | 1720 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | Unknown |
| Aircraft is a homebuilt? | No |
| 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 | Fixed |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | SMITH AND BARLOW ENTERPRISES |
| Aircraft Owner Street Address | 1122 MIKE JENSE CIR |
| Aircraft Owner City | PROVO |
| Aircraft Owner State | UT |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 84601 |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | PVU |
| Departure City | PROVO |
| Departure State | UT |
| Departure Country | |
| Departure Time | 1245 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | 41U |
| Destination City | EPHRAIM |
| Destination State | UT |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Apr 21 2001 4:04AM |
| 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 | -- |