Christen PITTS S-1T N77MN

Summary

On 26 June 2011 at about 17:15 local time, a Christen PITTS S-1T registered N77MN was involved in an accident near Alkali Lake, Oregon, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

26 June 2011 at 17:15

Classification

Accident

Location

Alkali Lake, Oregon, United States

Coordinates

43.1664, -119.4842

Aircraft

Christen PITTS S-1T

Registration

N77MN

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Burns → Lakeview

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR11LA290

1 person had minor injuries.

The loss of engine oil during cruise flight due to the failure of the front bearing oil seal.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.