Individually Owned: 150,657
Corporate Owned: 137,281
None Airport
Aircraft Accident/Incident Report
Chicago, Illinois 60601
Sunday, July 22, 2012 13:30 CDT
NTSB Narrative Summary Released at Completion of Accident
The pilot was on a cross-country flight in an experimental airplane when the engine began to “race.” The pilot tried to reduce power by adjusting the throttle, but the engine and propeller were unresponsive. He then made a forced landing to a soft field, and the airplane nosed over. Examination of the automotive engine revealed that the spline-shaft and adapter gears in the reduction gearbox were worn, which resulted in the gearbox's failure. According to the pilot, the gearbox was not a regularly inspected item for this particular engine/gearbox combination. At the time it failed, the gearbox had accrued 247 total hours since new.
NTSB Probable Cause Narrative
Failure of the automotive engine's reduction gearbox while in cruise flight.
Event Information
| Type of Event | Accident |
| Event Date | 7/22/2012 |
| Event Day of the Week | Sunday |
| Time of Event | 1330 |
| Event Time Zone | Central Daylight Time |
| Event City | Chicago |
| Event State | ILLINOIS |
| Event Country | -- |
| Zipcode of the event site | 60601 |
| Event Date Year | 2012 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 413635N |
| Event Location Longitude | 0872428W |
| Event Location Airport | None |
| 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 | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Pilot |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| 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) | -- |
| 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) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| 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) | 30657 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Oct 23 2012 1:17PM |
| User who most recently changed record | yeal |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N4970Y |
| NTSB Number | CEN12LA470 |
| 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 | YAMOKOSKI WILLIAM |
| Aircraft Model | GLASTAR |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 5377 |
| Certified Max Gross Weight | 1970 |
| 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 | Oct 25 2011 12:00AM |
| Airframe hours since last inspection | 87 |
| Airframe Hours | 1424 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | YAMOKOSKI WILLIAM |
| Aircraft Owner Street Address | 2000 FORRES AVE |
| Aircraft Owner City | SAINT JOSEPH |
| Aircraft Owner State | MI |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 49085-1607 |
| Operator is an individual? | No |
| Operator Name | YAMOKOSKI WILLIAM |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 2000 FORRES AVE |
| Operator City | SAINT JOSEPH |
| Operator State | MI |
| Operator Country | USA |
| Operator Zip code | 49085-1607 |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | OSH |
| Departure City | Osh Kosh |
| Departure State | WI |
| Departure Country | USA |
| Departure Time | 1200 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | BEH |
| Destination City | Benton Harbor |
| Destination State | MI |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Oct 10 2012 12:01PM |
| User who most recently changed record | yeal |
| 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 | -- |