Accident Overview
On October 16, 2016, at 1205 central daylight time, a Bellanca 17-31A, registration N93668, experienced a loss of engine power while climbing from a touch-and-go landing on runway 20 at Mc Alester Regional Airport (MLC), Mc Alester, Oklahoma. The airplane sustained substantial damage. The flight instructor and a private pilot/airplane owner received serious injuries. The airplane was newly registered to and operated by the pilot under 14 CFR Part 91 as an instructional flight for an airplane checkout. Day visual meteorological conditions prevailed. The flight originated from Sundance Airport (HSD), Oklahoma City, Oklahoma, about 0930.
Flight Sequence
According to the flight instructor, the airplane was preflighted and fueled to capacity at HSD. Flight planning indicated 30 gallons of fuel would remain upon arrival at MLC. The flight departed at 0930, proceeded to Ponca City Regional Airport (PNC) for an instrument approach and touch-and-go landing, then to Tulsa International Airport (TUL) for another touch-and-go, and finally to MLC.
During a visual approach to MLC, the flight instructor selected the left fuel tank as it was the fullest. Upon arrival, fuel gauges indicated left tank less than half full, right tank above quarter full, and auxiliary tank full. After a touch-and-go on runway 20, the airplane lost engine power while climbing through 100 feet above ground level. The instructor directed the pilot to fly best glide speed, verified fuel selector on left tank, mixture full rich, propeller and throttle full forward. About two seconds elapsed from power loss to flaring for landing.
Post-Accident Examination
The airplane touched down in a field about 200 feet south of the departure end of runway 20, impacting upright and sliding 30-40 feet. Both wing spars sustained substantial damage; no post-impact fire occurred. Propeller blade damage was consistent with torsional rotation.
Examination revealed left and right main fuel tanks contained no usable fuel; the auxiliary tank was approximately full. The main fuel supply line from the firewall to the gascolator, engine-driven pump, fuel servo, and flow divider were disconnected; no or only several drops of liquid consistent with aviation fuel were present. These lines were intact and not broken open. The bottom fuselage area near the fuel selector sustained impact damage, and fuel lines were separated at the fuel selector valve fittings. The gascolator screen was debris-free, and its bowl contained a few drops of fuel-like liquid.
Post-accident examination of the fuel selector could not determine its position due to impact damage. The pilot reported he could not feel the fuel detent and used the position indicator light to move the selector to the left tank position.
Engine and Maintenance Findings
The airplane total time at the last annual inspection was 2,724.15 hours; the engine (Lycoming IO-540-K1E5, serial L-11719-48) had 2,489.15 hours since new. Tachometer reading at the accident site was 2,480.20 hours. The engine rotated, and air was drawn into and expelled from bottom spark plug holes after removal. Compression by hand was low. Engine and valve train continuity to the accessory section was confirmed. Both magnetos rotated with electrical continuity through the ignition harness.
Left and right turbochargers (Garrett Allied Signal and Rajay Industries) were hand-rotatable with no record of overhaul since original installation. Turbocharger exhaust bypass valves contained dirt and debris; exhaust pipes were corroded to an unairworthy thickness. Duct and packing tape secured a piece of engine baffle to the front of the engine. Safety wire was installed in place of required hardware such as cotter pins, nuts, bolts, and washers.
A post-accident calibration check of the fuel tank transmitters was not performed.
Instructor Statements
The flight instructor stated he trusted the airplane owner's maintenance. He did not use the electric auxiliary fuel pump during fuel tank selection from right to left main tank, nor after the power loss, citing insufficient time. He noted he now teaches to change fuel tank selection outside the airport traffic pattern due to higher fuel flow demand. The airplane operations manual states the electric auxiliary pump is for starting and engine-driven pump failure; the landing checklist specifies selecting the fullest tank.
Probable Cause
The National Transportation Safety Board did not state a probable cause in the available source.