NTSB Factual Report

HISTORY OF FLIGHT

On August 27, 1994, at 1805 Pacific daylight time, a Beech D95A, N4835J, operated by Diamond K. Aviation, Inc., collided with terrain and was destroyed by a postimpact fire during a go-around at the Oakdale (uncontrolled) Airport, Oakdale, California. Visual meteorological conditions prevailed and no flight plan was filed. The flight instructor (CFI) possessed a commercial pilot certificate and was seriously injured. The second pilot possessed a commercial pilot certificate and was receiving multiengine flight training. She sustained fatal injuries. The instructional flight originated from Oakdale at 1643.

Another CFI, who was standing on the ground at the airport, witnessed the accident flight. This CFI was also a multiengine flight instructor and was familiar with the accident airplane. According to this CFI/witness, prior to the crash the accident airplane had performed three full stop landings at Oakdale. Then, the airplane departed the pattern. After several minutes, the airplane returned to the pattern. The witness heard the CFI transmit the airplane position. In the background of the transmission, the witness recalled hearing the sound of a gear warning horn. According to the witness, this indicated a throttle had been retarded and a single-engine approach may have been the intended maneuver which was in progress.

The witness further reported that as the accident airplane flew in the downwind leg, he heard a popping sound from one of the engines. The witness attributed this sound to a low engine power setting. The witness saw the airplane on the base and final legs, and nothing unusual was noted. The airplane overflew the landing threshold and descended to about 30 feet above the runway, but it did not land. According to the witness, he then heard the sound of engine power increasing, saw the airplane initiate a shallow climb, and saw the landing gear being retracted. The airplane then began turning left and flying nearly perpendicular to the runway. At the same time, its left bank angle gradually steepened until reaching over 90 degrees. The airplane's nose lowered, and it collided into a field next to the airport. Within seconds, a fire was observed at the impact site.

WRECKAGE INFORMATION

The airframe and engines were examined under the supervision of Federal Aviation Administration (FAA) personnel. The cockpit examination revealed the cowl flap switch for the left engine was in a position corresponding to the CLOSED position. The corresponding right engine cowl flap switch was found in the OPEN position. According to the witness, during simulated engine out operations, the cowl flaps are normally open on the engine developing power, and they are closed on the engine which is in the simulated zero thrust mode.

The fuel selector for the left engine was found in the OFF position. The fuel selector for the right engine was found in the MAIN tank position.

The right engine's propeller blades appeared to be in a high rpm (low-pitch) position, and the blades were bent and twisted. The left engine's propeller blades appeared to be in a feathered position, and the blades were not bent or twisted. No evidence of any preimpact mechanical failure was observed to any engine rotating or reciprocating components.

Regarding airframe structure, all airframe components were accounted for at the accident site. The continuity of the flight control system was established.

CREW INFORMATION

On September 9, 1994, the husband of the deceased student pilot was interviewed via telephone by the National Transportation Safety Board. In pertinent part, he reported that on the day of the accident, his wife had commenced her multiengine flight training. She had been in good health, did not smoke or drink, and was not using medication. The evening before the accident flight she had received her customary amount of sleep.

As of April 17, 1995, the Safety Board has not received any written statement from the surviving CFI. The FAA reported that a designated pilot examiner had issued the CFI a flight instructor certificate for multiengine land airplanes on August 9, 1994. Prior to the day of the accident, the CFI had provided multiengine flight training to one other student. The CFI's total experience as a multiengine instructor was between 7 and 8 hours of flight time.

NTSB Probable Cause

IMPROPER IN-FLIGHT PLANNING/DECISION BY THE FLIGHT INSTRUCTOR (CFI), AND THE CFI'S INADEQUATE SUPERVISION BY NOT ASSURING THAT THE MINIMUM CONTROL SPEED (VMC) WAS MAINTAINED. A FACTOR RELATED TO THE ACCIDENT WAS: THE CFI'S LACK OF EXPERIENCE IN MULTI-ENGINE INSTRUCTIONAL TRAINING.