Grumman G-164-A N910X

Summary

On 25 May 2000 at about 13:00 local time, a Grumman G-164-A registered N910X was involved in an accident near Toms River, New Jersey, 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

25 May 2000 at 13:00

Classification

Accident

Location

Toms River, New Jersey, United States

Coordinates

Not recorded

Aircraft

Grumman G-164-A

Registration

N910X

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Chatsworth → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

NYC00LA144

Nobody was injured.

The failure of the number 9 cylinder connecting rod, due to a primer leak initiation of a partial hydraulic lock. A factor in the accident was the unsuitable terrain, to which the forced landing had to be made.

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

Read the full NTSB narrative

After the third aerial application pass, the airplane's engine developed a severe vibration, then seized. The pilot dropped the chemical load, turned the airplane into the wind, and made a forced landing into a cranberry bog. Afterwards, the pilot reported that had he had felt no binding when he pulled the propeller through, to check for hydraulic lock during the preflight. He also stated that the airplane hadn't seemed to be developing full power for about a week prior to the accident. During the post-accident engine teardown, an upper (number 9) cylinder was removed, and a broken connecting rod was found. Metallurgical examination of the connecting rod fragments revealed well-defined crack arrest positions, indicative of fatigue, on the smaller fragment. The fracture features within the fatigue region were relatively uneven, and in several locations, the fatigue crack appeared to have extended in overstress. There were no visible metallurgical defects in the initiation area. The larger fragment contained features typical of an overstress. According Advisory Circular 65-12A, a partial hydraulic lock could cause a 'slightly bent connecting rod,' which could go unnoticed, but would be 'sure to fail later.' Upper cylinders on high wing aircraft have been known to be susceptible to hydraulic lock due to a leaking fuel primer.

Quoted verbatim from the NTSB record.