McDonnell Douglas 369E N992SD

Summary

On 30 January 1999 at about 23:43 local time, a McDonnell Douglas 369E registered N992SD was involved in an accident near Lake Elsinore, California, United States. 2 people were on board and 2 were seriously injured. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

30 January 1999 at 23:43

Classification

Accident

Location

Lake Elsinore, California, United States

Coordinates

Not recorded

Aircraft

McDonnell Douglas 369E

Registration

N992SD

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Public Use

Phase of flight

Not recorded

Route

Hemet → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX99GA083

2 people were seriously injured.

The pilot's failure to maintain main rotor rpm and her misjudged flare. Also causal was the failure of the company maintenance personnel to follow the procedures/directives in the engine manufacturer's operation and maintenance manual and their improper inspection of the engine. A factor was the oil starvation of the nos. 6, 7, and 8 bearings that resulted in a total loss of engine power.

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

Read the full NTSB narrative

While the pilot was maneuvering about 550 to 650 feet agl, the engine chip light illuminated followed by a complete loss of engine power. She performed an autorotation to a large, open field, flared high about 100 feet agl, then collided with the ground. The skids were found spread outward with the belly touching the ground. Two of the main rotor blades displayed evidence of coning. Post-accident investigation revealed that all components of the lubrication system were intact and functional. When the turbine was disassembled, bearings 6 through 8 were found destroyed and displayed evidence of heat distress and oil starvation. The number 5 bearing evidenced heat distress. The nos. 1 through 5 bearings and the gearbox were lubricated, but there was no visual evidence of oil present downstream from the number 5 bearing. There was scoring and debris present in the oil pump scavenge chamber. Over a period of about 72 flight hours and 1 1/2 months, there were 10 reported engine chip light activations. After three chip lights were reported, the turbine, gear box, and compressor assembly were replaced. Engine chip lights were reported six more times. The number 5 bearing and snap ring were found spinning; a new number 5 bearing was installed. The day of the accident, the chip light came on during a maintenance ground run, then came on again before the engine quit. According to the Allison Engine Operation and Maintenance Manual, 'a maximum of four occurrences of magnetic chip warning lights encountered within any 50 hours of engine operation requires removal of the engine for shipment to an Allison Authorized Maintenance Center (AMC).'

Quoted verbatim from the NTSB record.