NTSB Factual Report

On May 22, 2002, at 0005 central daylight time, a Cessna 172N single-engine airplane, N734KG, was substantially damaged when it impacted trees and terrain during a forced landing following a loss of engine power while in cruise flight near Glen Rose, Texas. The airplane was registered to Aer Mistral of Saginaw, Texas, and operated by Split S Aviation of Fort Worth, Texas. The private pilot and his passenger were not injured. Dark night visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations part 91 personal flight. The night cross-country flight originated from the Hicks Airfield Airport, near Fort Worth, Texas, at 2330, with San Antonio, Texas as the flights intended destination.

The 67-hour pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that during cruise flight at 2.000 feet, he initiated a climb to 3,000 feet. A few minutes later, the engine rpm dropped 200-300 rpm. The pilot stated he increased throttle to check for an rpm response. Subsequently, the engine lost power, and he initiated a forced landing. While approaching to land, he noticed trees in front of the airplanes flight path and started "looking for another place to land, but couldn't see anything because it was completely dark." Prior to landing, he decided to put 10-degrees of flaps down. The aircraft impacted tress coming to rest in the upright position.

Examination of the airplane by the FAA inspector who responded to the accident site, revealed that both wings were structurally damaged and the fuselage was wrinkled aft of the cabin area. An examination of the engine under the supervision of an FAA inspector, revealed the left magneto's internal gears did not rotate with the engine. Removal of the left magneto revealed only one of two rubber drive isolators inside the ignition harness cap. Internal inspection of the magneto revealed the contact points on the left hand side of the magneto did not open on rotation. Further examination of the airplane, revealed that the ignition key turned to the left magneto only. The pilot reported to the NTSB investigator-in-charge, that he did not touch any switch while exiting the aircraft.

A review of the aircraft logbooks revealed that the engine had accumulated 857 hours since the last major overhaul, which was completed on July 18, 2001. The airplane had accumulated 28 hours since the last 100-hour inspection, which was completed on May 14, 2002.

NTSB Probable Cause

The pilot's failure to set the ignition key to the both magnetos position, which resulted in a loss of engine power. Contributing factors were the failure of the left magneto, the lack of suitable terrain for the forced landing, and the dark night.