DEN99LA174

The airplane was equipped with a Rolls Royce (Allison) 250-B17F turbine engine. All the fuel tanks (wings, tips, fuselage) were topped off with Jet-A fuel (about 147 gallons) and Prist, a fuel additive. During the first attempt to start the engine, N1 reached about 30% with no temperature rise, so the pilot stopped the start sequence. After waiting about five minutes, a second start attempt was successful. Peak turbine outlet temperature (TOT) was 707 degrees C. Taxi, runup, and takeoff were normal. About 10 minutes after departure, as the airplane was climbing through 12,000 feet msl, 'the engine stopped, the generator light came on, and the torque needle went to zero.' An inflight restart was attempted but was not successful. The pilot made a forced landing on Highway 16. Oncoming traffic forced the pilot to depart the side of the road shearing off the nose wheel at the fork. The wings flexed during the off roadway excursion, causing the spar web and cap to buckle downward. The engine was later functionally tested successfully.

On September 5, 1999, approximately 1010 mountain daylight time, a Cessna P210N, N999KM, was substantially damaged when it collided with terrain during a forced landing 10 miles west of Santa Fe, New Mexico. The private pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed, and an IFR flight plan had been filed for the business flight being conducted under Title 14 CFR Part 91. The flight originated at Santa Fe approximately 1000.

The airplane was equipped with a Rolls Royce (Allison) 250-B17F turbine engine. The pilot said that in preparation for his return flight to San Jose, California, he had all the fuel tanks (wings, tips, fuselage) topped off with Jet-A fuel (about 147 gallons) and Prist, a fuel additive. He said that on his first attempt to start the engine, N1 reached only about 30% with no temperature rise, so he stopped the start sequence. After waiting five minutes, a second start attempt was successful. Peak turbine outlet temperature (TOT) was 707 degrees C. Taxi, runup, and takeoff were said to be normal.

The pilot said about 10 minutes after departure, as the airplane was climbing through 12,000 feet msl (mean sea level), "the engine stopped, the generator light came on, and the torque needle went to zero." An inflight restart was attempted but was not successful. The pilot made a forced landing on Highway 16. Oncoming traffic forced the pilot to depart the side of the road, shearing off the nose wheel at the fork.

Damage was originally assessed to be minor and the mishap was classified as an incident. Subsequent examination disclosed negative buckling of the spar web and cap caused by the wings flexing during the off roadway excursion.

According to Allison, a Federal Aviation Administration inspector "motored" the engine at least 3 times without verifying the amount of fuel in the lines and filters. The engine was shipped to National Airmotive for testing. On October 5 and 6, the fuel control was tested. After being reattached, the engine was started and stabilized at idle. Shortly thereafter, TOT began to rise and oil pressure dropped slightly. The engine was shut down. Two other engine starts were aborted due to high TOT. The next two engine starts were normal but the gearbox pressure was high. The engine was again shut down. On October 7, two engine starts were made. The first ended in a premature shutdown when "test stand hysteresis" caused the test cell throttle linkage to move to the OFF position. The second start was successful and performance calibration was completed.