Aero Commander CALLAIR A-9B N7924V

Summary

On 25 August 2003 at about 19:30 local time, a Aero Commander CALLAIR A-9B registered N7924V was involved in an accident near Driggs, Idaho, 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

25 August 2003 at 19:30

Classification

Accident

Location

Driggs, Idaho, United States

Nearest airport

Reed Memorial (U59)

Coordinates

43.7386, -111.0919

Aircraft

Aero Commander CALLAIR A-9B

Registration

N7924V

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Route

Driggs → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA03FA179

Nobody was injured.

A loss of engine power due to the improper installation of a counterweight roller pin retaining washer circlip, leading to the circlip coming out of its groove and the counterweight roller pin coming in contact with two of the engines connecting rods. Contributing to the accident were the fence and the uneven terrain.

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

Read the full NTSB narrative

During takeoff with a glider in tow, while passing through an altitude of 200 feet above the ground (agl), the aircraft's engine experienced a catastrophic failure. The pilot then released the glider and executed a forced landing on nearby terrain. Although the touchdown was successful, the aircraft hit a fence before the pilot could bring it to a stop. A teardown examination of the engine determined that the circlip holding one of the counterweight roller pin retaining washers had come out of the groove in the counterweight body. This lead to the roller pin coming in contact with the number five and number six connecting rods, and ultimately to the catastrophic failure. A comparison of wear pattern development on the subject circlip with the others on the counterweight body determined that it had come out of its retaining groove soon after the counterweight was overhauled about 21 hours prior to the accident. Wear patterns also indicated that the subject circlip had been installed with its "sharp edge" facing inwards, which is contradictory to the instructions contained in Textron Lycoming Service Instruction 1012F.

Quoted verbatim from the NTSB record.