On June 15, 1995, a Grumman G-164B (registration N6669Q) was involved in an aviation accident near Helena, MT. Investigators recorded the probable cause as: THE LOSS OF ENGINE POWER FOR UNDETERMINED REASONS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While maneuvering near the ground, an engine backfired and lost power. The pilot attempted a forced landing but the airplane impacted terrain in a bank. Examination revealed crankshaft binding, a cracked cylinder head, and heat distress.
Accident Details
During maneuvering in close proximity to the ground, the engine backfired two or three times and suddenly lost power. The pilot attempted to level the wings and execute a forced landing, but the airplane impacted terrain while in a bank.
Engine Examination
Post-accident examination of the engine revealed that the crankshaft was binding during rotation. Additionally, the No. 5 cylinder head was cracked, and the crankshaft exhibited evidence of heat distress. No evidence was found to indicate that these deficiencies occurred after the accident. Postimpact and thermal damage to the engine precluded a complete functional test and examination of the engine.
What happened in the 15 Jun 1995 Grumman G-164B accident near Helena, MT?
While maneuvering near the ground, an engine backfired and lost power. The pilot attempted a forced landing but the airplane impacted terrain in a bank. Examination revealed crankshaft binding, a cracked cylinder head, and heat distress.
What aircraft was involved and where did it happen?
The accident on 15 Jun 1995 involved a Grumman G-164B, registration N6669Q, at Helena, MT.
What was the probable cause of the accident?
THE LOSS OF ENGINE POWER FOR UNDETERMINED REASONS.
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