Grumman AA-1A N9330L

Summary

On 29 October 1989 at about 00:30 local time, a Grumman AA-1A registered N9330L, operated by John L. LEE, was involved in an accident near Borrego Springs, California, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 October 1989 at 00:30

Classification

Accident

Location

Borrego Springs, California, United States

Coordinates

33.1709, -116.2695

Aircraft

Grumman AA-1A

Registration

N9330L

Category

Airplane

Engines

1

Operator

John L. LEE

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Borrego Springs → San Diego

Aircraft damage

Substantial

Weather

VMC

Light

Dusk

NTSB number

LAX90LA015

1 person had minor injuries.

THE FAILURE OF THE ENGINE EXHAUST VALVE.

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

Read the full NTSB narrative

THE 23-YEAR-OLD RECENTLY CERTIFIED PRIVATE PILOT PURCHASED AN 18-YEAR-OLD FLYING CLUB AIRPLANE. THE AIRCRAFT AND ENGINE HAD BEEN OPERATED FOR A TOTAL OF 2093 HOURS. NO RECORD WAS FOUND OF THE ENGINE HAVING BEEN OVERHAULED. DURING THE AIRCRAFT'S LIFE, IT HAD BEEN INACTIVE FOR TWO PERIODS TOTALING 8 YEARS. DURING CRUISE FLIGHT, THE ENGINE LOST ALL POWER. THE PILOT MADE AN EMERGENCY LANDING IN THE DESERT, AND THE AIRCRAFT COLLIDED WITH A BERM AND NOSED OVER. EXAMINATION OF THE ENGINE, WHICH HAD A TBO OF 2400 HOURS IF KEPT IN CONTINOUS SERVICE, REVEALED THAT THE NO. 1 EXHAUST VALVE HEAD HAD SEPARATED FROM THE STEM WHICH WAS NECKED DOWN AT THE POINT OF FAILURE. THE ENGINE'S THREE OTHER EXHAUST VALVE STEMS WERE ALSO FOUND NECKED DOWN IN THE SAME GENERAL AREA.

Quoted verbatim from the NTSB record.