Accident Overview
On September 5, 2015, about 1836 central daylight time, a Cessna TR182 airplane, registration N4707S, impacted terrain following a forced landing to a field near Midland, Texas. The pilot was seriously injured at the time of the accident and succumbed to his injuries on September 29, 2015. The three passengers aboard were not injured. The airplane sustained substantial damage. The flight was operated by the pilot under 14 CFR Part 91 as a personal cross-country flight. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated from Midland International Air & Space Port (MAF) and was en route to El Paso International Airport (ELP).
Flight and Circumstances
The airplane departed from runway 16R at MAF (elevation 2,872 ft msl) and proceeded south. GPS data indicated the airplane climbed to 2,910 ft about one minute after takeoff and leveled off with a groundspeed of approximately 58 kts. The airplane remained at that altitude for about 32 seconds before descending, with groundspeed around 60 kts during level flight and airspeed decreasing to about 50 kts during the descent.
Pilot and Passenger Statements
Passengers reported that immediately after takeoff, the pilot experienced difficulties: the airplane was not developing power and would not climb. The pilot chose to land in a field rather than return to MAF. Passengers stated the pilot handled the airplane well during the forced landing. The airplane struck a rock, causing the pilot to sustain a broken back. Passengers evacuated the airplane unassisted.
In a postaccident interview, the pilot told an FAA inspector that the wastegate might not have opened, a problem he experienced on a previous flight where manifold pressure overboosted. Three days before the accident, a repair station replaced the manifold pressure gauge and bypass valve. During the accident takeoff, the airplane was configured with 10 degrees of flaps and mixture full rich. Full power was applied, and airspeed increased to 80–100 kts. As the airplane crossed the departure end of the runway, the pilot noticed manifold pressure was high and rpm low. He decided to continue but later executed a wheels-up forced landing when the airplane could not maintain altitude.
Aircraft Examination
Examination at the scene revealed substantial damage to the engine mounts, firewall, lower cowling, nose gear doors, and fuselage. The main landing gear were crushed upward. The propeller exhibited torsional bending, chordwise scratches, leading-edge nicks, and one blade was bent and twisted aft with material missing at the tip. Flight control continuity was confirmed. A portable GPS unit and engine monitoring device were retained for data readout.
Maintenance and Engine Findings
Records showed an annual inspection on February 19, 2015 (airframe time 2,142.2 hours). Between July 29 and August 19, 2015, the turbocharger wastegate was checked; the pressure relief valve was not opening correctly and was replaced, after which it functioned properly during a ground run. Service bulletin Lycoming SB-643 had not been complied with.
During an engine examination in Lancaster, Texas on October 29–30, 2015, continuity was found throughout. The dual magneto timing was left 18° BTC and right 16° BTC (proper timing is 23° BTC). The turbocharger wastegate actuating cable was frayed and kinked at both ends, binding when the throttle was advanced. The actuator arm on the bypass valve was corroded, and the fastening bolt and nut were seized.
Engine run tests on a trailer: after replacing a fouled spark plug, the engine ran to full power (2,400 rpm). An ignition test at 1,800 rpm showed both magnetos dropped about 300 rpm (operating limit is a drop no lower than 150 rpm). The turbocharger operated normally, achieving 31.5 inches of mercury manifold pressure at full power. The magneto was removed and disassembled; points were excessively worn, but after reassembly, the magneto operated from 0 to 3,000 rpm with no defects.
Engine Monitor Data
The engine monitoring device recorded 15 sessions from May 23 to the accident flight. Data from the accident flight showed: at engine start, after about 420 seconds, EGT, manifold pressure (MAP), and rpm began to climb. At 540 seconds (around takeoff), EGT exceeded 1,400°F, MAP rose to 31 inches, and rpm reached 2,500. At 700 seconds, rpm dropped to zero and EGT decreased to about 1,000°F, with MAP around 30 inches. All data ended 20 seconds later.