Bell UH-1E N333XL

Summary

On 23 January 2022 at about 18:30 local time, a Bell UH-1E registered N333XL, operated by Marquis Aviation, was involved in an accident near Gustine, California, 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

23 January 2022 at 18:30

Classification

Accident

Location

Gustine, California, United States

Nearest airport

Los Banos (LSN)

Coordinates

37.1023, -120.9758

Aircraft

Bell UH-1E

Registration

N333XL

Category

Helicopter

Year built

1967

Engines

1

Operator

Marquis Aviation

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Los Banos → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR22LA084

Nobody was injured.

Failure of the 90° gearbox due to the lack of lubricating oil, which resulted in a loss of rotational drive to the tail rotor and a subsequent loss of control of the helicopter.

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

Read the full NTSB narrative

The pilot was conducting aerial spray applications of a chemical to a field. He had checked the oil quantity of the 90° gearbox during the preflight check but did not recall the quantity of oil at the time. The pilot had operated the helicopter for about 45 minutes and, while making a turn, lost control of the helicopter. The helicopter descended and impacted terrain. Maintenance records revealed no anomalies. Postaccident examination of the 90° gearbox revealed severe damage to the internal components and no evidence of lubricating oil inside the housing. The pinion was severely deformed, which resulted in the loss of rotational drive to the tail rotor assembly and the subsequent loss of control. Examination of the oil level sight glass revealed that the inside was covered with a material that did not allow for sufficient viewing of the oil level. It is likely that, when the pilot looked at the oil level sight glass during his preflight check, he interpreted what he saw as an adequate amount of oil.

Quoted verbatim from the NTSB record.