NTSB Factual Report

On August 22, 2006, about 1715 mountain daylight time, a Kinnson Lancair IV-P Turbine amateur-built experimental airplane, N514PT, sustained substantial damage when it struck a fence and terrain during a forced landing following a loss of engine power about 2 miles north of the Helena Regional Airport, Helena, Montana. The private pilot, the sole occupant, received minor injuries. The airplane was being operated by the pilot under 14 CFR Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight that departed the Helena Airport about 1623.

According to the pilot, after flying in the local area for about 40 minutes, he returned to the airport to practice some takeoffs and landings. After completing the first landing, he departed and was climbing out with the landing gear and flaps retracted when he "noticed flames coming out of the right side exhaust stack." The engine lost power, and the pilot executed a forced landing in a field. During the landing roll, the airplane impacted irrigation ditches and a fence.

An FAA inspector examined the airplane and reported that the right wing spar was broken. He further reported observing dents in the exhaust stacks that appeared to be from turbine blade material breaking off the turbine wheels and exiting the engine. The inspector oversaw a read out of engine parameters stored in avionics equipment installed in the airplane. According to the inspector, the data revealed "over temp and over torque of the engine for in excess of 60 seconds." The pilot stated that the accident could have been prevented by having equipment installed in the airplane that would prevent turbine over temperature by automatically limiting the fuel flow to the turbine.

NTSB Probable Cause

The total loss of engine power as a result of turbine over temperature due to the pilot's failure to follow proper procedures for engine operation. A contributing factor was the lack of suitable terrain for the ensuing forced landing.