American Aviation Corp (Aac) AA-1A N9394L

Summary

On 11 October 2000 at about 10:14 local time, a American Aviation Corp (Aac) AA-1A registered N9394L was involved in an accident near Philadelphia, Pennsylvania, 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

11 October 2000 at 10:14

Classification

Accident

Location

Philadelphia, Pennsylvania, United States

Nearest airport

Northeast Philadelphia (PNE)

Coordinates

40.0667, -75.0000

Aircraft

American Aviation Corp (Aac) AA-1A

Registration

N9394L

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Philadelphia → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Dawn

NTSB number

IAD01LA002

1 person had minor injuries.

A hole in the #4 piston for undetermined reasons which resulted in engine oil starvation and engine stoppage.

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

Read the full NTSB narrative

The airplane was on a traffic observation flight when it experienced a total loss of engine power. The pilot performed a forced landing to a schoolyard and escaped uninjured. Initial examination revealed heat damage to the #4 cylinder and no oil in the engine. Removal of the #4 cylinder revealed a hole in the #4 piston at the 12 o'clock position beneath the piston ring lands. The hole carried through to the interior of the piston. Removal of the #2 cylinder revealed that the #1 connecting rod was separated from the crankshaft. In addition to the hole through the #4 piston, examination revealed a deep groove in the side of the piston in line with the forward piston pin plug. The plug was worn and heat damaged, with significant material loss. Material transfer in line with the piston plug was observed on the wall of the #4 cylinder. The oil-scraper piston rings on the #1 and #2 pistons were installed backwards. The #3 cylinder had 3 base nuts installed upside down. Examination of the #1 and #2 cylinder assemblies revealed they were Superior cylinders. The number #3 and #4 cylinder assemblies were reworked Lycoming cylinders. The individual piston part numbers could not be determined. Examination of the maintenance records revealed the owner/operator replaced the #3 and #4 cylinder assemblies 337 aircraft hours prior to the accident. The owner/operator serviced the engine with 80 weight oil, and returned the airplane to service. The #1 and #2 cylinder assemblies were replaced by a maintenance facility 235 aircraft hours prior to the accident, and the engine was serviced with mineral oil as recommended by the engine manufacturer.

Quoted verbatim from the NTSB record.