On May 1, 1991, a Cessna 421 (registration N18DF) operated by Executive Airmotive was involved in an aviation accident near Englewood, CO. Investigators recorded the probable cause as: Exhaust system failure resulting in loss of turbocharger input on both engines. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Aircraft suffered exhaust system failure during initial climb from high-altitude airport, losing turbocharger input on both engines. Unable to return, pilot conducted emergency landing in rolling, soft field; landing gear collapsed and aircraft sustained damage.
Accident Overview
During the initial climb after takeoff from a high-altitude airport, the aircraft was operating at a gross weight 70 pounds below its maximum. Shortly after departure, both engines experienced a loss of input to their turbochargers. The cause of this loss was determined to be an exhaust system failure.
Sequence of Events
With reduced power available due to the loss of turbocharger input, the pilot was unable to return to the departure airport. An emergency landing was initiated in a field. The terrain of the field was rolling and soft, complicating the landing.
Damage
During the landing roll, the landing gear collapsed. The aircraft subsequently slid during the final phase of deceleration. This sliding motion resulted in damage to the engine nacelles and the underside of the aircraft.
Probable cause
Exhaust system failure resulting in loss of turbocharger input on both engines.