Christen Industries INC PITTS S-1T accident near Alkali Lake, Oregon, June 26, 2011
On June 26, 2011 at about 5:15 pm local time, a Christen Industries INC PITTS S-1T, registered N77MN, was substantially damaged in an accident during enroute (cruise) near Alkali Lake, Oregon. It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The loss of engine oil during cruise flight due to the failure of the front bearing oil seal.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 26, 2011 · about 5:15 pm local time
- Place
- Alkali Lake, Oregon · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Christen Industries INC PITTS S-1T · all PITTS S-1Ts on the register
- Registration
- N77MN · registry record · serial 1040
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, during cruise flight, a large amount of oil suddenly covered the windscreen, causing her to initiate a precautionary off-airport landing as the oil pressure dropped to zero. Because of the uneven terrain in area in which she was flying, suitable landing sites were minimal. During the landing, the pilot attempted to pitch the tail-wheel airplane upward in order to drag the tail along the ground to slow the airspeed. The pilot stated that she had no response from the elevator or ailerons. The airplane impacted the uneven terrain in a nose-low attitude and cartwheeled, resulting in structural damage to all four wings and the fuselage. Examination of the recovered engine revealed that the front bearing oil seal was partially extruded from the crankcase nose seal bore. No additional mechanical anomalies were noted during the examination of the engine or airframe. The reason for the front bearing oil seal becoming extruded from the crankcase bore area was undetermined.
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) defining event
- Off-field or emergency landing during landing
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng front section › Failure
- factor Environmental issues › Physical environment › Terrain › Sloped/uneven › Effect on operation
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; single-engine sea
- Flight time: 2,316 hours in all; 1,650 in this make and model; 40 in the last 90 days; 10 in the last 30 days; 2,270 as pilot in command
- Last flight review: November 18, 2009
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: ctr
- Injury: minor injuries
The aircraft
- Airframe total time: 1,919 hours
- Last inspection: condition inspection, January 11, 2011; 70 hours since
- Maximum gross weight: 1,150 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming AEIO-360-A1E (piston); 0 hours total
The flight
- Departed from: Burns OR at 4:50 pm
- Destination: Lakeview OR
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 150° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 63°F (17°C), dew point 37°F (3°C)
- Altimeter: 30.04 inHg
- Observation at 4:53 pm from KBNO, 34 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.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR11LA290.