17 May 20075:31 reconstruction3K views

Single-Engine Failure Ends in Fatal Spin During Missed Approach

Timeline

17 May 2007 — The Baron departed Oshawa Municipal Airport in Ontario for a flight toward Wilmington, Delaware.

En route — The left engine lost power and the crew diverted toward another airport.

Approach — The airplane emerged from cloud in level flight near the approach end of the intended runway.

Missed approach — The pilot initiated a climbing left turn and entered cloud again.

Final descent — The airplane entered a flat spin and descended toward wooded terrain.

Impact — The Baron struck terrain about one-half mile south-southwest of the approach end of the runway; all three occupants died.

The emergency began with an engine failure

A Beechcraft A55 Baron was approaching for a landing in instrument meteorological conditions when its left engine failed. The crew diverted toward an alternate airport, but the approach became a single-engine missed-approach situation. The airplane entered a climbing turn after the missed approach and subsequently descended in a flat spin before striking wooded terrain near the airport. The investigation found a major mechanical failure in the left engine and concluded that the loss of control occurred during the single-engine missed approach.

The left engine had suffered a major internal failure

The NTSB examination found an approximately 5.5-inch hole in the left-engine crankcase. A teardown identified damage concentrated around the aft counterweight assembly, including fracture of the aft-top hanger blade leading bushing bore and separation of the aft-top counterweight assembly. The investigation did not identify another mechanical failure that explained the loss of power.

The missed approach became the decisive phase

The accident occurred after the airplane had already diverted because of the engine problem. The Baron was operating in instrument conditions, and the pilot attempted the missed approach after the airplane emerged from cloud near the runway. The subsequent climbing turn and loss of control left the aircraft descending in a flat spin. The NTSB's probable-cause finding centered on the pilot's failure to maintain aircraft control during the single-engine missed approach after the left-engine counterweight failure. Clouds were identified as a contributing factor.

Maintenance history was part of the investigation

The aircraft was on its first flight after an annual inspection. The engines had accumulated about 308 hours since they had been disassembled and inspected following an earlier gear-up landing. Work on the left engine at that time included installation of new snap rings on the counterweight assemblies. The later teardown focused on the counterweight system because of the evidence found in the damaged engine.

Aircraft: Beechcraft A55 Baron
Date: 17 May 2007
Location: Three fatalities
Category: Dunkirk, New York

Sources

NTSB final report, NYC07FA119: https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/65803/pdf
ASN registration/occurrence reference: https://asn.flightsafety.org/

Audio from the original air traffic control recording, sourced from public recordings and released investigation records. The reconstruction, animation and written account are our own.