Cessna 180B N180GK

Summary

On 19 September 2014 at about 20:30 local time, a Cessna 180B registered N180GK, operated by Norris Gary L, was involved in an accident near Piscataquis County, Maine, United States. 2 people were on board and 2 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

19 September 2014 at 20:30

Classification

Accident

Location

Piscataquis County, Maine, United States

Coordinates

44.6949, -69.3826

Aircraft

Cessna 180B

Registration

N180GK

Category

Airplane

Year built

1959

Engines

1

Operator

Norris Gary L

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Mud Pond → Lake Ross

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA14LA446

2 people had minor injuries.

The fatigue fracture of the No. 3 exhaust valve, which initiated at the outer surface of the valve stem and resulted in the subsequent total loss of engine power over terrain unsuitable for landing.

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

Read the full NTSB narrative

The pilot reported that, while maneuvering the float airplane about 2,500 ft above ground level, he heard a "slight squeal" coming from the engine before it started to sputter. After the airplane had descended to about 1,500 ft, the engine and propeller "completely stopped." The pilot determined that the airplane would not reach a nearby lake and chose an unpaved road in the woods for the forced landing. The right wing struck a tree about 60 ft above the ground, and the airplane then impacted the road, which resulted in substantial damage to the wings, fuselage, and empennage. Examination of the engine revealed that the crankshaft could be rotated freely by hand, and removal of the oil sump revealed piston material and the No. 3 exhaust valve head, which was fractured at the stem below the head. Disassembly of the engine revealed normal wear and appearance on all of the cylinders except for the No. 3 cylinder, piston, and exhaust valve. Metallurgical examination of the No. 3 exhaust valve revealed that the fracture had initiated at the outer surface of the valve stem and that the valve had fractured due to fatigue at the transition of the stem to the valve.

Quoted verbatim from the NTSB record.