On July 19, 1998, a Navion G (registration N2498T) was involved in an aviation accident near Telluride, CO. Investigators recorded the probable cause as: Pilot operating the aircraft with an overly lean mixture. A factor was unsuitable terrain for a forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a visual approach, the engine lost all power while turning base leg for landing. The aircraft subsequently landed in trees off the approach end of the intended runway. Examination revealed an overly lean mixture but no mechanical failure.
Overview
A cross-country flight ended with an off-airport landing after the engine lost all power during the visual approach. The pilot was turning base leg for landing when the power loss occurred. The aircraft touched down in trees located off the approach end of the intended runway.
Post-Accident Examination
Subsequent examination of the engine revealed no evidence of mechanical failure or malfunction. However, the spark plugs exhibited white carbon-like deposits, which are indicative of an overly lean fuel mixture. The fuel system was compromised due to impact damage, preventing verification of the fuel quantity at the time of the accident.
Investigation Findings
Investigators noted the presence of white carbon material on the spark plugs, consistent with an overly lean mixture. No other anomalies were identified in the engine or its components. The exact amount of fuel remaining could not be determined because of the damage sustained during the landing.