Hughes 369 N58251

Summary

On 27 October 2020 at about 21:33 local time, a Hughes 369 registered N58251, operated by Windward Aviation Inc, was involved in an accident near Honolulu, Hawaii, 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

27 October 2020 at 21:33

Classification

Accident

Location

Honolulu, Hawaii, United States

Coordinates

21.3453, -157.8066

Aircraft

Hughes 369

Registration

N58251

Category

Helicopter

Year built

1978

Engines

1

Operator

Windward Aviation Inc

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

External Load

Phase of flight

Not recorded

Route

Waialua → Kahului

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC21LA003

Nobody was injured.

A partial loss of engine power due to an obstructed fuel line as a result of the separation of the circlip from the pin used on the fuel start pump. The reason for the circlip separation could not be determined based on the available evidence.

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

Read the full NTSB narrative

During longline operations, the helicopter lost partial power and the main rotor rpm decreased. The pilot jettisoned the external load and the helicopter impacted trees, resulting in substantial damage. The engine continued to run after impact, and the pilot performed an emergency engine shutdown. Examination revealed that the start fuel pump was damaged. The circlip and pin that held the flapper valve in place in the bypass inlet were missing, and the flapper valve was wedged against the sidewall of the bypass inlet, obstructing about 50% of the discharge port. The pin was located in the fuel line between the start fuel pump and the engine-driven fuel pump; the circlip was not found. No other mechanical malfunctions were found that would have precluded normal operation. The pin found in the fuel line and obstruction from the flapper valve located in the start fuel pump likely induced restricted fuel flow from the engine-driven fuel pump to the engine, which resulted in a partial loss of engine power. Based on the available evidence, the reason for the separation of the circlip from the pin could not be determined.

Quoted verbatim from the NTSB record.