Grumman G164 N62375

Summary

On 20 June 2021 at about 12:00 local time, a Grumman G164 registered N62375, operated by Scott Flying Service, was involved in an accident near Sedgwick, Arkansas, 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

20 June 2021 at 12:00

Classification

Accident

Location

Sedgwick, Arkansas, United States

Coordinates

35.9867, -90.8959

Aircraft

Grumman G164

Registration

N62375

Category

Airplane

Year built

1988

Engines

1

Operator

Scott Flying Service

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Fontaine → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN21LA287

Nobody was injured.

The total loss of engine power due to the failure and disengagement of the torque sensor assembly front spur gear from its splined shouldered shaft due to a loose self-locking nut.

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

Read the full NTSB narrative

The pilot was conducting an agricultural flight when the airplane had a sudden total loss of engine power. The pilot stated that the sound of the engine went from normal to silent, with no indication of an engine issue before the loss of engine power. The airplane impacted a levee and nosed over in a flooded rice field during the forced landing. The airplane’s empennage, aft fuselage, and engine mounts were substantially damaged during the forced landing. A postaccident engine examination and disassembly revealed the torque sensor assembly front spur gear was disengaged from the splined shouldered shaft on which it was installed. Additionally, the self-locking nut that secured the front spur gear to the shaft had backed off which allowed the front spur gear to disengage from the shaft. The examination and testing were unable to determine if the front spur gear self-locking nut was improperly torqued at installation or if it became loose during operation due a loss of retention. However, had the self-locking nut not been seated properly at installation, the disengagement of the front spur gear would likely have occurred well before the accident (2,541.5 hours since the overhauled torque sensor was installed on the engine). Additionally, no anomalies were found with the self-locking nut to suggest why it would have lost retention during operation. The engine-driven fuel pump and fuel control unit (FCU) are driven through a series of gears in the accessory gearbox, including the front spur gear, and any failure in the gear train that drives the fuel pump and FCU would prevent the fuel pump from delivering fuel to the FCU to sustain engine operation, resulting in an uncommanded engine shutdown.

Quoted verbatim from the NTSB record.