On July 1, 1984, an Aeronca 15AC (registration N1436H) operated by Howard Francis Bates was involved in an aviation accident near Ester, AK. Investigators recorded the probable cause as: Failure of a deteriorated oil outlet line from the oil cooler resulting in loss of oil and oil pressure. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft landed in spruce trees after the engine lost oil pressure due to a failed oil line. The pilot admitted postponing replacement of oil lines during the last annual inspection.
Accident Overview
The aircraft executed a forced landing into the tops of small spruce trees after the engine lost oil pressure and was subsequently shut down by the pilot.
Pilot Account
The pilot later admitted that the oil lines required replacement during the last annual inspection, which occurred on June 22, 1984. He postponed the replacement and later forgot to complete the maintenance in the excitement of resuming flight operations on floats after a two-year hiatus.
Mechanical Failure
Investigators determined that a badly deteriorated oil outlet line from the oil cooler had failed, resulting in the loss of engine oil and oil pressure. The failure of this component led directly to the loss of engine power.
Probable cause
Failure of a deteriorated oil outlet line from the oil cooler resulting in loss of oil and oil pressure.
Frequently asked questions
What happened in the 1 Jul 1984 Aeronca 15AC accident near Ester, AK?
An aircraft landed in spruce trees after the engine lost oil pressure due to a failed oil line. The pilot admitted postponing replacement of oil lines during the last annual inspection.
What aircraft was involved and where did it happen?
The accident on 1 Jul 1984 involved an Aeronca 15AC, registration N1436H, operated by Howard Francis Bates, at Ester, AK.
What was the probable cause of the accident?
Failure of a deteriorated oil outlet line from the oil cooler resulting in loss of oil and oil pressure.
A SkyWalk Join't 3 paraglider crashed into the ground near Las Vizcachas, Chile, on September 1, 2024. The pilot and passenger sustained serious spinal…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2024-09-01DGAC Chile
A Cessna 172N struck electrical cables while on final approach to land at Aucó Aerodrome in Chile. The pilot was uninjured, but the aircraft sustained damage…
A Bombardier DHC-8-402 suffered a tail strike during landing at Puerto Williams on September 9, 2024. All 76 occupants were unharmed, but the aircraft…
A MYD JS-MD 3 glider veered off the runway and struck a wall at Vitacura Aerodrome on January 6, 2025. The pilot was uninjured, but the aircraft sustained…
A recreational paraglider flight in Puchuncaví, Chile, ended with the pilot sustaining serious injuries after a rapid descent and impact with a hillside on…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2025-03-29DGAC Chile
A Tecnam P2006T landed on its belly at an aerodrome in Poland after the crew failed to confirm landing gear deployment. The incident resulted in no injuries…