Mooney M20C accident near Elma, Washington, July 22, 2009
On July 22, 2009 at about 9:47 pm local time, a Mooney M20C, registered N6422U, was destroyed in an accident during enroute (cruise) near Elma, Washington. It was an aerial observation flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A total loss of engine power during cruise flight due to the fatigue failure of the number 4 cylinder connecting rod.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 22, 2009 · about 9:47 pm local time
- Place
- Elma, Washington · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Mooney M20C · all M20Cs on the register
- Registration
- N6422U · no longer on the register · serial 2169
- Damage
- Destroyed
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane was returning to its home airport following an aerial observation mission. A witness reported that the airplane was making a clattering noise as it flew over her home and commented that it sounded as if it was running out of oil. The witness estimated the airplane to be 100-150 feet above ground level. A second witness reported that the airplane descended into the tree canopy and collided with power transmission lines. Post accident examination of the engine revealed extensive thermal and impact related damage. The main bearings exhibited erosion and copper was visible. A large hole was observed in the engine crankcase above the number four cylinder bay and mechanical damage was observed to the area surrounding the cylinder. The number four connecting rod remained attached to the piston; however, the connecting rod was separated from the crankshaft at the base of the yoke. Fragments of the associated connecting rod cap and corresponding bolt were found within the engine oil sump; only residual oil (less than one quart) was observed within the sump along with debris, which was consistent with main bearing material and had obscured the oil pickup screen. Two fractures were found on the connecting rod near the end of the rod. The first noted was a fatigue fracture that initiated at the crankshaft end connecting rod journal surface just below the boss for the connecting rod bolt/nut. On the opposite side of the connecting rod, in a similar location, a second fracture was identified. The fracture was the result of mechanical overload and initiated at the connecting rod journal surface. The connecting rod bolt fracture surface exhibit features consistent with mechanical overload. The lack of engine oil found in the crankcase is believed to have contributed to the main bearing erosion; however, it was not determined if the bearing erosion was the initiating event.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Powerplant sys/comp malf/fail during enroute (cruise)
- Loss of engine power (total) during enroute (cruise) defining event
- Off-field or emergency landing during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during emergency descent
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
- Aircraft › Fluids/misc hardware › Fluids › Oil › Fluid level
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng oil sys › Not specified
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Fatigue/wear/corrosion
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 6,000 hours in all
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 3,231 hours
- Last inspection: annual inspection, May 1, 2009
- Maximum gross weight: 2,575 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming O-360 SER (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: KOLM Olympia WA at 9:17 pm
- Destination: KOLM Olympia WA
- Flight plan: not recorded
Weather at the time
- Light: daylight
- Wind: from 016° at 16 knots, gusting 20
- Visibility: 10 statute miles
- Sky: overcast at 1,500 ft
- Temperature: 64°F (18°C), dew point 55°F (13°C)
- Altimeter: 30.03 inHg
- Observation at 9:53 pm from KSHN, 19 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.