Grumman G-164 N48564

Summary

On 5 April 2004 at about 15:00 local time, a Grumman G-164 registered N48564 was involved in an accident near Nezperce, Idaho, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

5 April 2004 at 15:00

Classification

Accident

Location

Nezperce, Idaho, United States

Coordinates

46.2394, -116.2406

Aircraft

Grumman G-164

Registration

N48564

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Nezperce → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA04LA065

Nobody was injured.

The circumferential fracture of the number seven cylinder head while en route to an aerial fertilizer application, leading to a forced landing on soft terrain, resulting in the collapse of the right main gear leg. Factors include soft terrain at the location where the pilot found it necessary to attempt the forced landing.

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

Read the full NTSB narrative

While en route to apply dry fertilizer to a field, the aircraft's engine popped and then experienced a significant loss of power. Because there was not sufficient power to keep the aircraft airborne, the pilot elected to execute a forced landing in a nearby field. He therefore started dumping his load of fertilizer, and attempted to set the aircraft down on the soft terrain. Although the touchdown was successful, soon thereafter the main gear sank into the soft terrain, and the right main gear leg folded aft. As the gear leg collapsed, the nose and right wing of the aircraft impacted the terrain. A post-accident inspection of the engine revealed that the head of the number seven cylinder had fractured circumferentially just above the location where the head screws into the cylinder barrel. Although the head had not separated from the barrel, the fracture was far enough around the barrel that it created a misalignment of the cylinder geometry to an extent that the intake valve would not close. There was no indication of detonation or any other anomaly that would have been expected to apply greater than normal loads to the cylinder structure.

Quoted verbatim from the NTSB record.