20040922029879A

(-23) The accident flight originated at flg after arriving from dvt. The aircraft was not refueled, however the pilot stated that he drained the sump and confirmed no contamination was present. The pilot stated that he could not get the engine started and requested technical assistance from wiseman aviation, who checked and cleaned battery and starter cables. After startup the pilot taxied to runway 21, and performed a run-up. The pilot was advised by the tower of a wind change and asked him if he would like a runway change, which he declined. The pilot stated that on the takeoff run he adjusted the mixture for peak performance, however he did not identify or reference the POH procedure, except to adjust for maximum RPM. The POH page 3-4 states that the high altitude power setting should be accomplished by adjusting the mixture for a fuel flow corresponding to the altitude markings on the fuel flow gage. The takeoff run of the accident aircraft was in excess of 5,500' after which the aircraft became airborne and would not climb above 20' AGL. The estimated takeoff distance should have been around 1500'. Witness statements indicate that the aircraft did not become airborne until an estimated 5,500'. Witness statements also indicate the engine was surging and made sounds of power changes throughout the takeoff run. The pilot's statement that the aircraft would not climb or accelerate above 20' AGL appears to confirm a power/performance interruption. The pilot aborted the flight and touched down 13' into the overrun of runway 21 at which point the aircraft slid off of the overrun into the dirt and down the embankment. Due to the rough terrain the nose gear strut collapsed aft and dug into the ground causing the aircraft to nose over completely to an inverted position. The propeller did not exhibit signatures of high power or numerous rotational signatures. The FAA inspector, and representatives from tcm and Cessna aircraft performed post accident inspection of the engine. Prior to the test run the spark plugs were examined for condition and all exhibited a dark carbon like appearance without lead fouling. The NTSB authorized a test run of the engine. The test run performed was unremarkable and the engine appeared to perform normally, in all power ranges, displaying normal fuel flows. After the test run the compressions were checked on all cylinders and were found to be within factory specifications. No power plant defects could be detected. The reason for the alleged power loss reported by the pilot could not be confirmed.