Individually Owned: 150,657
Corporate Owned: 137,281
Wittman Regional Airport
Aircraft Accident/Incident Report
Oshkosh, Wisconsin 54902
Wednesday, June 29, 2011 10:03 CDT
NTSB Narrative Summary Released at Completion of Accident
The accident occurred during the initial flight testing of the experimental amateur-built airplane. The pilot reported that, during the initial climb, at an altitude of about 200 feet above the ground, the engine began to lose power. He notified the tower air traffic controller of his engine emergency and began a turn to remain clear of nearby buildings. The airplane encountered a ditch during the forced landing and the forward fuselage and firewall were substantially damaged.
The airframe had accumulated 4 hours since it was issued an airworthiness certificate and the engine had accumulated 5.7 hours since its last major overhaul. The pilot/builder replaced the carburetor, spark plugs, and a cylinder since the last engine overhaul. A postaccident examination of the engine revealed that both spark plugs for the No. 4 cylinder were loosely installed into the cylinder head. The upper spark plug for the No. 4 cylinder was not seated on its cylinder gasket. Several spark plugs were removed and exhibited features consistent with the engine operating at a rich carburetor mixture setting. Although a carburetor-icing probability chart indicated that there was a serious potential for carburetor ice accumulation while operating at a reduced engine power setting, the postaccident investigation could not determine if carburetor ice contributed to the loss of engine power.
The postaccident investigation was unable to determine the reason for the loss of engine power, which could have been a result of the incorrectly installed spark plugs on the No. 4 cylinder, an excessively rich carburetor mixture setting, an accumulation of carburetor ice before takeoff, or any combination of the aforementioned issues.
NTSB Probable Cause Narrative
The loss of engine power during initial climb for undetermined reasons.
Event Information
| Type of Event | Accident |
| Event Date | 6/29/2011 |
| Event Day of the Week | Wednesday |
| Time of Event | 1003 |
| Event Time Zone | Central Daylight Time |
| Event City | Oshkosh |
| Event State | WISCONSIN |
| Event Country | -- |
| Zipcode of the event site | 54902 |
| Event Date Year | 2011 |
| Event Date Month | 6 |
| 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 | KOSH |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| 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 | 1011 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | KOSH |
| Elevation of weather observation facility | 808 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | EDT |
| 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) | 21 |
| Dew Point at event time (in degress fahrenheit) | 13 |
| Wind Direction (degrees magnetic) | 180 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 3 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.15 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | KOSH 291511Z 18003KT 10SM CLR 21/13 A3015 RMK AO2= |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 1 |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 29463 |
| NTSB Notification Source | FAA - Great Lakes ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Dec 19 2011 9:16AM |
| User who most recently changed record | foxt |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N56PK |
| NTSB Number | CEN11LA429 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Keesler |
| Aircraft Model | W8 Tailwind |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1953 |
| Certified Max Gross Weight | 1300 |
| 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 | Jun 27 2011 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 4 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C91-A |
| Aircraft Owner Name | Patrick E. Keesler |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Neenah |
| Aircraft Owner State | WI |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 54956-9054 |
| Operator is an individual? | Yes |
| Operator Name | Patrick E. Keesler |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | Neenah |
| Operator State | WI |
| Operator Country | USA |
| Operator Zip code | 54956-9054 |
| 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) | Flight Test |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | KOSH |
| Departure City | Oshkosh |
| Departure State | WI |
| Departure Country | USA |
| Departure Time | 1003 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | KOSH |
| 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 | Dec 19 2011 9:19AM |
| User who most recently changed record | foxt |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 09 |
| Runway Length | 6178 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |