On July 22, 1991, a Cessna 172P (registration N52433) operated by Civil Air Patrol, Inc. was involved in an aviation accident near Sylva, NC. Investigators recorded the probable cause as: THE PILOT'S IMPROPER IN-FLIGHT PLANNING, AND HIS FAILURE TO MAINTAIN A PROPER ALTITUDE WHILE MANEUVERING IN THE CANYON. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 5 related events involving the same aircraft type or operator are linked below.
A pilot and two observers searching for marijuana plants in a mountainous canyon encountered a downdraft during slow flight. Airspeed decayed, escape routes became unavailable, and the pilot guided the aircraft into trees, after which it fell to the ground.
Flight Details
A pilot and two observers were flying a mission to identify marijuana plants in a mountainous canyon. The aircraft was being operated at a slow airspeed when it encountered a downdraft. The airspeed subsequently decayed, and the pilot found that escape routes from the canyon were no longer viable. In response, the pilot slowed the aircraft further and directed it into the tree line. Following the impact with trees, the airplane fell to the ground below.
Investigation Report
Investigators examined the wreckage and determined that there was no evidence of mechanical malfunction or failure. The pilot had not reported any mechanical issues prior to the accident. The ambient temperature at the time was measured at 92 degrees Fahrenheit. The aircraft was near its maximum gross weight, and the density altitude was calculated to be about 6,000 feet.