Individually Owned: 150,657
Corporate Owned: 137,281
Whiteman Airport
Aircraft Accident/Incident Report
Valencia, California 91355
Tuesady, July 7, 2009 12:30 PDT
NTSB Narrative Summary Released at Completion of Accident
The pilot reported that he was flying back to the airport when the experimental airplane began to shake violently, which was accompanied by a loud noise. The propeller blades departed the airplane and the engine subsequently experienced an overspeed, followed by a loss of power. During a forced landing, the airplane encountered a ditch and spun 90 degrees. Metallurgical examinations of the blades could not determine the method of failure. Tests and calculations indicate that the engine could not rotate fast enough to liberate the blades unless their strength had been degraded in some way. Several possible sources of such degradation were observed, but none of them could be conclusively identified as the cause of the event. The strength of the blades was provided by the wood of the propeller, and the fractures in the wood of the three blades appeared similar, making no obvious difference to identify the initial separation. The blades were found very close to one another, suggesting that they were liberated at nearly the same point of rotation during a single revolution of the propeller. Assuming one blade had accumulated enough damage to initiate the event, the resulting unbalanced vibration was sufficient to eject the other two blades, in the process creating fractures similar to those on the damaged blade. The measured gap between hub halves was less than the expected gap for new, correctly installed blades. Such over-clamping of the hub is one problem that has apparently occurred in the past due to improper torquing. It is possible that the hub had previously been over-clamped to a greater degree, with subsequent adjustment leading to an under-clamped condition. Looseness in this area can lead to fatigue cracking, because it allows for the variations in stresses from repetitive loads to be maximized on the components being connected. Bird impact was ruled out, but the blade might have been struck by debris picked up during takeoff. Although there was no staining or other signs of degradation in the wood, one blade had an area that was susceptible to moisture due to a manufacturing defect, which could have allowed the decrease in the stiffness and strength of wood structures and may have played a role in liberating the blades.
NTSB Probable Cause Narrative
The failure and separation of a propeller blade for undetermined reasons.
Event Information
| Type of Event | Accident |
| Event Date | 7/7/2009 |
| Event Day of the Week | Tuesday |
| Time of Event | 1230 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Valencia |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 91355 |
| Event Date Year | 2009 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 342354N |
| Event Location Longitude | 1183309W |
| Event Location Airport | Whiteman Airport |
| Event Location Nearest Airport ID | WHP |
| 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 | 1003 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1225 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 100 |
| Weather Observation Facility ID | WHP |
| Elevation of weather observation facility | 1003 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 27 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Light and Variable |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.92 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 26935 |
| NTSB Notification Source | FAA Comm Center |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | May 13 2010 2:37PM |
| User who most recently changed record | coos |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N926JB |
| NTSB Number | WPR09LA340 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Unknown |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Bender |
| Aircraft Model | Kitfox |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | KBS 079 |
| Certified Max Gross Weight | 1200 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| 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 | Fixed |
| Aircraft, Type of Last Inspection | Conditional |
| Date of Last Inspection | Sep 15 2008 12:00AM |
| Airframe hours since last inspection | 49 |
| Airframe Hours | 278 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | FELDMANN JAMES R |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | BURBANK |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 91501-1631 |
| Operator is an individual? | Yes |
| Operator Name | FELDMANN JAMES R |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | BURBANK |
| Operator State | CA |
| Operator Country | USA |
| Operator Zip code | 91501-1631 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | -- |
| 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 | WHP |
| Departure City | Los Angeles |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1135 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | WHP |
| Destination City | Los Angeles |
| Destination State | CA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | May 13 2010 2:24PM |
| User who most recently changed record | coos |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |