On January 20, 1993, a Boeing A75N1 (registration N56924) operated by Denton, Larry E. was involved in an aviation accident near Medicine Bow, WY. Investigators recorded the probable cause as: The failure of the number 7 cylinder intake valve rocker arm, which resulted in an engine stoppage and a subsequent forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft experienced multiple engine surges after reaching cruising altitude, resulting in a forced landing on difficult terrain during nighttime conditions due to a mechanical failure.
What happened
The pilot reported that shortly after leveling off at 14,000 feet mean sea level, the engine surged three times and then stopped. A forced landing was executed onto rocky, upsloping terrain, under dark night conditions.
The investigation
Subsequent disassembly of the engine revealed that the number 7 cylinder intake valve rocker arm had failed.
Probable cause
The failure of the number 7 cylinder intake valve rocker arm, which resulted in an engine stoppage and a subsequent forced landing.
What happened in the 20 Jan 1993 Boeing A75N1 accident near Medicine Bow, WY?
An aircraft experienced multiple engine surges after reaching cruising altitude, resulting in a forced landing on difficult terrain during nighttime conditions due to a mechanical failure.
What aircraft was involved and where did it happen?
The accident on 20 Jan 1993 involved a Boeing A75N1, registration N56924, operated by Denton, Larry E., at Medicine Bow, WY.
What was the probable cause of the accident?
The failure of the number 7 cylinder intake valve rocker arm, which resulted in an engine stoppage and a subsequent forced landing.
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…