Summary
On May 12, 1995, a Cessna 170B (N4366B) was involved in an incident near Chickaloon, AK. All 1 person aboard were uninjured. The aircraft sustained substantial damage.
The National Transportation Safety Board determined the probable cause of this incident to be: THE FRACTURE OF THE CRANKSHAFT RESULTING IN SEPARATION OF THE PROPELLER AND PROPELLER FLANGE IN-FLIGHT. A FACTOR ASSOCIATED WITH THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR AN EMERGENCY LANDING.
On May 11, 1995, about 1715 Alaska daylight time, a wheel equipped Cessna 170B airplane, N4366B, sustained substantial damage during a forced landing onto Alaska State Highway 1, near Chickaloon, Alaska. The solo private pilot was not injured. The 14 CFR Part 91 cross country flight operated in visual meteorological conditions. The flight departed Northway, Alaska, about 1500.
The pilot reported that while in cruise flight at 6,500' msl, the engine began to vibrate abruptly, followed almost immediately by a loud noise and the separation of the propeller from the engine. He said the only suitable forced landing area was the highway, and he was forced to land downwind and uphill due to surrounding terrain. The airplane bounced, and went into a ditch adjacent to the highway.
This incident is documented in NTSB report ANC95LA053. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N4366B.
Accident Details
Probable Cause and Findings
THE FRACTURE OF THE CRANKSHAFT RESULTING IN SEPARATION OF THE PROPELLER AND PROPELLER FLANGE IN-FLIGHT. A FACTOR ASSOCIATED WITH THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR AN EMERGENCY LANDING.
Aircraft Information
Registered Owner (Current)
Analysis
On May 11, 1995, about 1715 Alaska daylight time, a wheel equipped Cessna 170B airplane, N4366B, sustained substantial damage during a forced landing onto Alaska State Highway 1, near Chickaloon, Alaska. The solo private pilot was not injured. The 14 CFR Part 91 cross country flight operated in visual meteorological conditions. The flight departed Northway, Alaska, about 1500.
The pilot reported that while in cruise flight at 6,500' msl, the engine began to vibrate abruptly, followed almost immediately by a loud noise and the separation of the propeller from the engine. He said the only suitable forced landing area was the highway, and he was forced to land downwind and uphill due to surrounding terrain. The airplane bounced, and went into a ditch adjacent to the highway.
The pilot could give no reason why the propeller separated from the engine. In his written statement to the NTSB, he noted that the propeller, the propeller mounting flange, and the forward portion of the crankshaft had separated from the engine and were not recovered.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ANC95LA053