Hughes 369D N220AL

Summary

On 16 November 1992 at about 14:34 local time, a Hughes 369D registered N220AL, operated by Haverfield Corporation, was involved in an accident near Carlsbad, 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

16 November 1992 at 14:34

Classification

Accident

Location

Carlsbad, California, United States

Coordinates

33.1308, -117.2995

Aircraft

Hughes 369D

Registration

N220AL

Category

Helicopter

Engines

1

Operator

Haverfield Corporation

Operating rule

Part 91: General Aviation

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

San Diego → Palomar

Aircraft damage

Substantial

Weather

VMC

Light

Dusk

NTSB number

LAX93LA044

Nobody was injured.

FAILURE OF THE OVERRUNNING CLUTCH ASSEMBLY BEARING FOR UNDETERMINED REASONS.

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

Read the full NTSB narrative

DURING FLIGHT THE AIRCRAFT BEGAN TO VIBRATE SEVERELY, AND THEN THERE WAS A LOUD BANG. THE AIRCRAFT BEGAN TO DESCEND WITH SMOKE IN THE CABIN, AND THE ENGINE OUT LIGHT AND HORN WAS ACTIVATED. DURING LANDING, THE HELICOPTER SETTLED INTO THE DIRT, ROCKED FORWARD, THEN AFT. ACCORDING TO THE PILOT, THE MAIN ROTOR BLADES STRUCK THE TAIL BOOM DUE TO LOW ROTOR RPM. EXAMINATION REVEALED THAT AN OVERRUNNING CLUTCH BEARING HAD FAILED. A METALLURGICAL EXAMINATION COULD NOT DETERMINE THE CAUSE OF THE FAILURE BECAUSE OF THE EXTENT OF DAMAGE. THE BEARING ASSEMBLY & INNER RACE (SHAFT) WAS EXPOSED TO TEMPERATURES GREATER THAN 1500 DEG F. THE OVERRUNNING CLUTCH WAS REPORTEDLY LUBRICATED 7 HRS PRIOR TO THE ACCIDENT, AT THE LAST 100-HR INSPECTION. THE INSPECTION IS ALSO CONSIDERED A 300-HR INSPECTION; ACCORDING TO MDHC AT THE 300-HR INSPECTION THE BEARING IS TO BE REMOVED, CLEANED, INSPECTED AND REPACKED.

Quoted verbatim from the NTSB record.