On June 8, 1983, a Cessna TU206G (registration N732ZQ) operated by Monarch Aviation was involved in an aviation accident near Molina, CO. Investigators recorded the probable cause as: Separation of the rubber hose from the turbocharger compressor duct to the throttle body duct. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.
A pilot experienced engine power loss after a detonating sound at 17,500 ft MSL. Investigation revealed separation of the rubber hose from the turbocharger compressor duct to the throttle body duct.
Incident Summary
During a flight, the pilot reported leveling off at 17,500 feet MSL when the engine produced a detonating sound and subsequently lost power. The manifold pressure dropped to approximately 12 inches of mercury. Fuel pressure remained normal, but the cylinder head temperature decreased rapidly. As the aircraft descended to 9,000 feet MSL, the engine momentarily surged, with manifold pressure rising to about 16 inches of mercury. When the pilot leaned the fuel mixture, the engine began to vibrate severely, prompting the pilot to shut down the engine.
Investigation Findings
A post-accident examination revealed that the rubber hose connecting the turbocharger compressor duct to the throttle body duct had separated. This separation resulted in a loss of boost pressure and subsequent power loss. No other anomalies were noted in the engine or fuel system.
Probable cause
Separation of the rubber hose from the turbocharger compressor duct to the throttle body duct.