Individually Owned: 150,657
Corporate Owned: 137,281
Wittman Regional Airport
Aircraft Accident/Incident Report
Oshkosh, Wisconsin 54902
Thursday, July 26, 2012 16:30 CDT
NTSB Narrative Summary Released at Completion of Accident
The pilot was performing at an air show and entered the aerobatic box with a 45 degree descending roll. At an airspeed of 150 mph, the pilot pulled up into a loop and then initiated a “snap-on-top-of-a-loop” maneuver. The pilot’s seat then broke, and the pilot and seatback fell backward onto the rear seat and rear control column, temporarily jamming the flight controls. The pilot was then able to recover the airplane to a “right-side-up” position with wings level. He flew away from the crowd to assess the situation and subsequently landed without further incident.
An examination revealed that the airplane’s seat bottom frame was not equipped with a required reinforcement truss stiffener. The manufacturer reviewed its production work orders and discovered that a batch of 10 seats were produced that were not constructed with the truss stiffener and, therefore, did not conform with the airplane’s production type certificate. As a result of this investigation, the manufacturer added steps to the seat production and inspection procedures to ensure proper seat assembly. Additionally, the manufacturer added to the seat welding fixture a locator (a visual cue) for the truss stiffener parts. Further, Service Letter 437 was published indicating that owners should perform a one-time inspection to ensure that the seat bottom frame contains the required reinforcement truss stiffener.
NTSB Probable Cause Narrative
The failure of the pilot’s seat bottom frame due to the manufacturer’s improper production, installation, and inspection of that seat bottom, which resulted in a temporary loss of control during an air show performance.
Event Information
| Type of Event | Incident |
| Event Date | 7/26/2012 |
| Event Day of the Week | Thursday |
| Time of Event | 1630 |
| Event Time Zone | Central Daylight Time |
| Event City | Oshkosh |
| Event State | WISCONSIN |
| Event Country | -- |
| Zipcode of the event site | 54902 |
| Event Date Year | 2012 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 435904N |
| Event Location Longitude | 0883325W |
| Event Location Airport | Wittman Regional Airport |
| Event Location Nearest Airport ID | OSH |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 808 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1553 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | OSH |
| Elevation of weather observation facility | 808 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | CDT |
| 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) | 21 |
| Wind Direction (degrees magnetic) | 60 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 9 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.68 |
| 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 | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 31150 |
| NTSB Notification Source | Pilot, Greg Koontz |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Mar 20 2013 2:12PM |
| User who most recently changed record | bowl |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N60GK |
| NTSB Number | CEN12IA498 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | AMERICAN CHAMPION AIRCRAFT |
| Aircraft Model | 8KCAB |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1115-2012 |
| Certified Max Gross Weight | 1950 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| 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 | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | 11.2 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C126 |
| Aircraft Owner Name | Pilot |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | ASHVILLE |
| Aircraft Owner State | AL |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 35953 |
| Operator is an individual? | No |
| Operator Name | Pilot |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | ASHVILLE |
| Operator State | AL |
| Operator Country | USA |
| Operator Zip code | 35953 |
| 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) | Air Race/Show |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | OSH |
| Departure City | Oshkosh |
| Departure State | WI |
| Departure Country | USA |
| Departure Time | 1625 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | OSH |
| Destination City | Oshkosh |
| Destination State | WI |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 19 2013 8:14PM |
| User who most recently changed record | male |
| 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 | -- |