CEN10FA021

The pilot reported that during the initial climb he retarded the power lever and the engine did not respond and remained at full power. He attempted to cycle the power level and only experienced a change in power output when the control was at the flight idle position and at the full-power position. While preparing to land, the pilot cycled the power between flight idle and full power in an effort to maintain airspeed and attain the proper glide path. During final approach, the pilot attempted to increase power again but the engine did not respond and remained at flight idle. The airplane landed short of the approach end of the runway and came to rest inverted. A postaccident examination of the engine and associated components revealed no mechanical malfunctions or failures that would have precluded normal operation. The investigative team and an independent certificated flight instructor duplicated the engine power anomalies described by the pilot by manipulating the propeller condition lever in place of the power lever, which is likely what the pilot did prior to the accident.

HISTORY OF FLIGHT On October 18, 2009, about 1330 mountain daylight time, a Cessna P210N, Silver Eagle conversion airplane, N7217S, impacted terrain following a loss of engine power during an emergency approach to Garfield County Regional Airport (RIL), Rifle, Colorado. The airplane was substantially damaged and the commercial pilot received minor injuries. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. Visual meteorological conditions prevailed for the local flight which had just departed RIL. The pilot reported that during departure from Runway 26, about one minute after takeoff, he attempted to retard the power lever to a lower power setting. The engine did not respond to his attempts until he reached the flight idle position. At that time the engine power immediately decreased to flight idle. He then pushed the power lever forward to increase power, but the engine did not respond until the power lever reached the full forward position. The pilot made a turn to downwind in preparation for an emergency landing. While preparing to land the pilot cycled the power between flight idle and full power an undetermined number of times in order to maintain airspeed. While on final the pilot attempted to increase power, but the engine did not respond. He stated he thought he saw the propeller in a feathered position prior to impact. The airplane landed short of the approach end of the runway and flipped onto its back. The airplane came to rest about 300 feet east of the Runway 26 approach end and about 100 feet south of the extended runway centerline. The initial impact marks began 110 feet east of the airplane wreckage and were consistent with the airplane hitting with the landing gear extended. The airplane was inverted and the Hartzell three-blade propeller was separated from the airplane and found in a feathered position about three feet from the main wreckage. The right wing was partially buckled at the mid-point. The tail cone was bent approximately 20 degrees midway between the aft cabin and the leading edge of the horizontal stabilizer. The vertical stabilizer and rudder exhibited crush damage consistent with impact damage. The left wing was buckled at the midpoint. Flight control cable continuity was verified from the cockpit controls to each flight control surface. PERSONNEL INFORMATION The pilot, age 71, held a Commercial Pilot certificate with instrument airplane, single-engine land, single-engine sea, and multiengine land ratings. The pilot indicated on the Safety Board Form 6120.1, Accident/Incident Report 1,423 total flight hours, 169 hours in type, 36 hours in the last 90 days, four hours in the last 30 days, and one hour in the last 24 hours. The pilot’s last flight review was March 31, 2009. His last Class 3 medical was issued October 22, 2008, with the limitation “Glasses.” AIRCRAFT INFORMATION The airplane had been converted by O & N AircraftModifications, Inc, to their Silver Eagle conversion on May 9, 2008. This conversion involved replacing the Teledyne Continental Motor Company (TCM) TSIO-520-P with a Rolls-Royce (RR) model 250-B17F2 turbine engine. The original RR 250 engine, serial number (S/N) CAE-881359 was replaced by O & N Aircraft Modifications, Inc, with a new engine, S/N CAE-881371, on January 28, 2009, after the airplane experienced a nose gear collapse on landing. That incident occurred on June 5, 2008, at Prince George (CYXS), British Columbia, Canada. The last airplane inspection was an annual type, conducted on March 1, 2009. The airplane had accumulated 3,780 total hours at the time of the accident. RESEARCH AND TESTING Engine power control continuity could not be verified between the engine and cockpit. The power lever and condition lever control cables were found separated from the coordinator unit in the engine compartment. Both cables and associated attachment points with the coordinator unit were removed and sent to the Safety Board metallurgical laboratory for examination. Both cables were found to have separated due to overload forces. The engine was examined by investigators at the Rolls-Royce facility at Indianapolis, Indiana. Examination of the compressor revealed no evidence of foreign object damage or failure. Witness marks made by the compressor blades were consistent with little or no rotation at the time of impact. The accessory gearbox was undamaged and exhibited no evidence of failure or malfunction. The turbine section was not damaged and examination revealed no evidence of failure. No condition was noted during the examination which would have precluded normal engine operation. The Honeywell fuel control unit was removed and examined by investigators at the Honeywell facility in South Bend, Indiana. The unit was bench tested and its performance did not indicate any condition that would have prevented it from operating normally. The power turbine governor and the propeller governor, each produced by Woodward Governor Company, were removed and examined at the manufacture’s facility. Both units were functionally tested and no evidence of any pre-accident malfunctions was found with either unit. ADDITIONAL INFORMATION A C-210 Silver Eagle pilot, with approximately 3,700 hours in type, spoke to the accident pilot after the accident and provided the following statement. “In questioning [the pilot] regarding the operation and subsequent crash, he informed me that after takeoff he experienced [an] unexplained situation. He stated that after he reduced power and the engine went to flight idle, then upon applying power the engine went to full power. I have thought about this and the only example of this situation I can come up with is the possibility of movement of the wrong throttle quadrant lever. The reason for my thought of this possibility is that I do about 45 demonstrations of this particular aircraft per year. On more than one occasion, I have hada novice (in the Eagle or Turbine experience) reach over without looking and grab the conditioning lever, thinking it was the throttle. On every occasion, I have corrected the client. I pay particular attention when demonstrating no matter what the skill level of the so called pilots I fly with, even the experienced ones make mistakes. To [further my suspicion], I took one of the (non-enhanced) Silver Eagles and tried an experiment with the conditioning lever in different positions. In flight, I reduced the conditioning lever to a position of about 1,450 on the propeller. In this position by bringing back the throttle, engine went to flight idle (flight idle being 1,250 rpm and full in this position 1,450). [Advancing] the throttle the engine went to immediate high power (max torque). Next, I moved the conditioning lever to a higher prop rpm, and the same scenario played out, except this time the advance to full power was a little less rapid (yet very rapid). In both situations there was not any intermediate throttle position, just flight idle to full power.” The investigation team operationally ground tested an engine’s response to having the propeller condition lever manipulated. During the operational test the power lever was limited to an intermediate power setting between idle and takeoff power. Manipulation of the propeller condition lever during the engine run resulted in the propeller revolutions dropping to a power level similar to flight idle. During one reduction of the condition lever the engine quit.