Piper PA32R N9084J

Summary

On 12 November 2016 at about 01:50 local time, a Piper PA32R registered N9084J, operated by STATE OF ALASKA Department Of Public Safety, was involved in an accident near Bethel, Alaska, 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

12 November 2016 at 01:50

Classification

Accident

Location

Bethel, Alaska, United States

Coordinates

60.7728, -161.8867

Aircraft

Piper PA32R

Registration

N9084J

Category

Airplane

Year built

1985

Engines

1

Operator

STATE OF ALASKA Department Of Public Safety

Operating rule

Public Use

Phase of flight

Not recorded

Route

Bethel → Nunapitchuk

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC17LA006

1 person had minor injuries.

A total loss of engine power due to oil starvation, which resulted from an oil cooler leak at a fractured brazed seam.

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

Read the full NTSB narrative

The commercial pilot reported that the airplane took off, and at 800 ft, the engine oil pressure dropped to zero. The pilot stated that he immediately turned back to the departure airport and that, while he was maneuvering for landing, the engine began "popping loudly," and engine oil began emanating from the oil access panel and splattered onto the windscreen. Shortly after, the engine lost all power. The pilot subsequently conducted a forced landing on tundra about 1 mile from the airport. During the landing roll, the nose and left landing gears collapsed, and the left wing and fuselage impacted terrain. After the accident, a large puddle of oil was found on the airport ramp where the engine was started. During the recovery of the airplane, the engine oil access panel was found open with no dipstick present. The oil access panel had an impact mark on the underside that was about the same size as the dipstick top. Postaccident examination of the engine revealed that there were holes and fractures on the top and bottom of the crankcase and that no oil was present in the oil tank. Several connecting rods were separated from the crankshaft and exhibited mechanical and thermal damage, consistent with oil starvation. When compressed air was applied to the right oil cooler, air was expelled from a small fracture between the brazed plates. Detailed examination of the oil cooler revealed an overstress fracture at a brazed seam; the fracture exhibited signatures of overstress with no evidence of preexisting defects. No anomalies of the oil pressure and temperature regulating systems were noted. It is likely that the oil cooler seam fractured after the engine start and that most of the engine oil was expelled before takeoff. Once the oil supply to the engine was exhausted, the internal friction of the metal components resulted in thermal damage and connecting rod fractures and the subsequent loss of all engine power. It is possible that the crankcase was pressurized during the engine failure sequence, which resulted in the oil dipstick being ejected from the engine. The reason for the engine oil overpressure in the oil cooler could not be determined.

Quoted verbatim from the NTSB record.