Individually Owned: 150,657
Corporate Owned: 137,281
Sonoma Valley Airport
Aircraft Accident/Incident Report
Sonoma, California 95476
Saturday, May 14, 2005 10:30 PDT
NTSB Narrative Summary Released at Completion of Accident
The airplane collided with the runway during an aborted takeoff following a partial loss of engine power. Prior to departure the pilot completed an engine run-up, observing no anomalies with the engine gauges or the engine's performance. During the takeoff, as the pilot began to lift off of the runway surface, the engine began to surge and he noticed a subsequent degradation in climb performance. After reaching about 30 to 40 feet above ground level (agl), he realized the airplane would not be able to continue the departure and opted to perform an emergency landing on an alternate runway. The airplane collided with the runway in a 15-degree nose low attitude. A post accident examination of the engine found that the spark plugs, the cylinders, and piston heads were heavily sooted; signatures consistent with an excessively rich fuel mixture. No other anomalies were found that would have precluded the engine from normal operation. An examination of the fuel servo revealed that the unit had a black coloration in the throat section and blue staining present near the idle valve. These signatures were consistent with a rich fuel mixture and a continuous fuel leak. During the bench testing of the servo, several small fuel leaks were noted at the idle valve, fuel diaphragm, and center body seal. Flow tests at high power settings revealed that the fuel servo was running rich, well over the prescribed maximum flows for that unit. The unit was about 28 years old and did not appear to have ever been overhauled. A representative from the engine manufacturer stated that based on the fuel servo's tested flow, the engine would have been running very rich and most likely could not have produced normal power. The servo manufacturer issued a Service Bulletin in 1990 that recommends that the unit be overhauled at engine TBO or every 10 years.
NTSB Probable Cause Narrative
a partial loss of engine power, which resulted from the fuel servo leaking and generating an excessively rich fuel/air mixture. A factor was the owner's failure to comply with a service bulletin.
Event Information
| Type of Event | Accident |
| Event Date | 5/14/2005 |
| Event Day of the Week | Saturday |
| Time of Event | 1030 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Sonoma |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 95476 |
| Event Date Year | 2005 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 381324N |
| Event Location Longitude | 1222658W |
| Event Location Airport | Sonoma Valley Airport |
| Event Location Nearest Airport ID | 0Q3 |
| 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 | 10 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1054 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | APC |
| Elevation of weather observation facility | 35 |
| Distance of event from weather observation facility (units?) | 8 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 20000 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 22 |
| Dew Point at event time (in degress fahrenheit) | 15 |
| Wind Direction (degrees magnetic) | 210 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.02 |
| 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) | 20001 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | May 15 2005 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Aug 29 2006 3:49PM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | WP-FAT-FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N765GL |
| NTSB Number | LAX05LA173 |
| 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 | Great Lakes |
| Aircraft Model | 2T-1A-2 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 0765 |
| Certified Max Gross Weight | 1800 |
| 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 | Annual |
| Date of Last Inspection | Nov 1 2004 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Charles Martin |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | San Francisco |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 94118 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | San Francisco |
| Operator State | CA |
| Operator Country | USA |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| 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 | Yes |
| Departure Airport Code | 0Q3 |
| Departure City | Sonoma |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1025 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Takeoff - initial climb |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Apr 27 2006 6:25PM |
| User who most recently changed record | COOS |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 25 |
| Runway Length | 2700 |
| Runway Width | 45 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |