Grumman G-164A N963X

Summary

On 31 July 2015 at about 16:30 local time, a Grumman G-164A registered N963X, operated by Precision Aerial Ag, LLC, was involved in an accident near Emmett, Kansas, 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

31 July 2015 at 16:30

Classification

Accident

Location

Emmett, Kansas, United States

Coordinates

39.3072, -96.0564

Aircraft

Grumman G-164A

Registration

N963X

Category

Airplane

Year built

1968

Engines

1

Operator

Precision Aerial Ag, LLC

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Wamego → Wamego

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN15LA330

1 person had minor injuries.

The engine failure due to several loose, damaged cylinder stud nuts and hold-down bolts. Contributing to the accident was maintenance personnel’s failure to detect that the cylinder nuts and hold-down bolts were not properly secured during the engine’s most recent inspection.

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

Read the full NTSB narrative

The commercial pilot was conducting an agricultural application flight. The pilot reported that, while making a spray run, he heard a loud "bang" and saw a puff of smoke emanate from the upper right side of the engine, followed by the propeller seizing. He made a forced landing in a field, and the airplane collided with some bushes and then nosed over. Examination of the engine revealed several loose cylinder stud nuts and hold-down bolts that appeared to have been pushed up on the cylinder skirt. Several of the studs, particularly the No. 4 cylinder stud, were stretched and looked to be nearly pushed out of the engine crankcase. One cylinder was almost separated from the crankcase. Examination of the airplane's maintenance logbooks revealed that the engine had received a major overhaul more than 8 years before the accident. The records indicated that, since that time, inspections of the cylinder heads and the cylinder hold-down studs had been conducted in compliance with two Federal Aviation Administration airworthiness directives. The engine was last inspected about 3 months before the accident. During this inspection, maintenance personnel checked the cylinder bases and heads for cracks and loose studs; however, they did not detect that the cylinder nuts and hold-down bolts were not properly secured.

Quoted verbatim from the NTSB record.