Bonanza Engine Failure and Repair

June 17, 2001

Engine Failure

On Sunday June 17th 2001 N8309N had an incident. On a trip from Sugarbush (0B7) to Norwood (OWD) about 20 miles northwest of Nashua (ASH) the engine started running rough. In flight diagnosis failed to determine what was wrong. Number 4 cylinder showed first hot (1550 degrees) then cold (250 degrees). Neither mag was better. The other fuel tank was tried.

The incident occured at night, IFR in VMC conditions. An emergency landing was made at Nashua, power was available for landing and taxi. Tower reported smoke from the exhaust. Subsequent diagnosis of the engine found a quarter sized hole in number 4 cylinder. Metal was found in the oil filter and in the oil drained from the sump.

Damaged Piston

These Pictures show the damage to the piston. Detonation caused either by a plugged injector or a damaged spark plug caused the gradual pitting of the piston and eventual catastrophic failure of the piston.

Repair Progress

An overhauled engine is being installed at Edmunds Aircraft Service, Nashua, New Hampshire 800 435-4740. They have been kind enough to allow me to work on the aircraft. My knowlege of how to work on airplanes is limited and this has been an opportunity to learn.

The engine was removed from the plane and rests beside it.

Have a look at N8309N with an empty hole up front!

Inside the engine compartment a hole has been worn through the front of the cowl and several cracks have been induced. These are all caused by a hose clamp on an induction line at the front of the engine. If this clamp is rotated at engine installation no damage occurs. Sadly all overhauled engines place the clamp in the position that damages the cowl.

The engine compartment is completely cleaned, degreased and corrosion is scuffed and sanded off.

The nose gear is removed. All parts are cleaned and stripped and will be painted prior to reassembly.

The front gear well is also cleaned and prepared for painting.

Every shop has it's characters. Here young Mr. Edmonds builds a model.

The engine has returned from overhaul long before we are ready for it.

A small crack is discovered in the gear well area. The crack is stop drilled and a small doubler is made to reenforce the area.

These parts are hung out ready for painting. The ones on the right include a lot of parts removed for repair or access.

Kevin grins at us while he puts time in on another aircraft.

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