Hughes 500C N7172Z

Summary

On 20 February 1995 at about 16:00 local time, a Hughes 500C registered N7172Z was involved in an accident near Key Largo, Florida, 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 February 1995 at 16:00

Classification

Accident

Location

Key Largo, Florida, United States

Coordinates

25.0794, -80.4392

Aircraft

Hughes 500C

Registration

N7172Z

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Opa Locka → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

MIA95LA078

Nobody was injured.

The pilot's misjudgment of altitude and failure to apply collective cushioning pitch during an autorotation resulting in a hard landing. Contributing to the accident was a total loss of engine power due to a loose coupling B-nut on the pneumatic fuel control system, and improper maintenance inspection of helicopter by unknown maintenance personnel.

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

Read the full NTSB narrative

The pilot stated he was in cruise flight at 500 feet agl when he experienced a total loss of engine power. He entered autorotation towards a highway. At 100 feet he initiated a deceleration and applied initial collective pitch at about 20 feet. Collective cushioning pitch was not applied. The helicopter collided with the ground ventral fin first, rocked forward, and slid about 150 feet. Examination of the helicopter revealed the B-nut on the after filter coupling of the fuel pressure differential switch was loose. The coupling B-nut was tightened. The engine was run in an engine test cell and developed adequate power. When the coupling B-nut was loosened the engine shut down.

Quoted verbatim from the NTSB record.