Stinson SR-10-C accident at Clarksburg, West Virginia, 11 May 1949

Accident narrative

On May 11, 1949, All American Airways Trip 1, a Stinson SR-10-C, crashed and burned following a takeoff from Benedum Airport in Clarksburg, West Virginia. The aircraft was destroyed and both occupants were killed.

**The flight** The air mail pickup flight departed Pittsburgh, Pennsylvania, at approximately 0630 for Huntington, West Virginia, operating under Visual Flight Rules. The crew consisted of Captain William Bruce Burkhart, who had 3,058 flying hours, and Flight Mechanic William John Steinbrenner.

After picking up and dropping mail in flight at several stations, the aircraft landed at Clarksburg to discharge cargo. The cargo was unloaded without stopping the engine, and the captain remained in the pilot's seat. No new cargo was loaded, leaving the aircraft's gross weight upon departure at 3,982 pounds, which was 168 pounds below the maximum allowable and properly distributed.

**The takeoff and crash** The Stinson taxied to the end of the 3,800-foot Runway 5 and waited long enough to accomplish a pre-takeoff engine check, though it is unknown if an engine run-up was made. The takeoff run began at about 0730. Witnesses stated that the aircraft took a longer than normal run before becoming airborne, and that they did not hear the characteristic engine noise normally heard when the propeller is set in the low pitch position for takeoff. They described the engine as not sounding as if it was developing full takeoff power.

After traveling approximately 2,500 feet down the runway and becoming airborne, the aircraft began a shallow climbing turn to the right toward rising terrain. At an altitude of approximately 200 feet, the turn was observed to steepen to an approximately 45-degree bank. The pilot then lost control, and the aircraft crashed in a near-vertical attitude on the side of a small hill. Fire consumed all inflammable parts of the aircraft.

Weather at the time included high broken clouds, an estimated 5,000-foot ceiling, and five miles visibility in haze and smoke. The Board did not consider weather a contributing factor.

**What the investigation found** The wreckage was located approximately 1,900 feet east of the northeast end of Runway 5, at an elevation about 100 feet above the runway. The airframe remained virtually intact despite intense heat, and examination indicated all flight controls were capable of normal operation.

In the cockpit, the throttle was open, the mixture full rich, and carburetor heat off. The fuel control valve was found in the off position. To investigate this, tests were conducted on an identical All American Airways Stinson. The tests showed that an engine at takeoff settings (2,240 r.p.m.) would stop eleven seconds after the fuel valve was closed, and sixteen seconds under cruise conditions (2,000 r.p.m.). Because the accident occurred approximately two minutes after takeoff, and damage to the crankshaft indicated the engine was producing appreciable power at impact, the Board concluded the fuel valve's position was changed by impact forces.

Examination of the propeller governor revealed it was set at 2,000 r.p.m., the setting normally used for cruising and mail pickups. The Board noted that climb performance would be reduced with the propeller at cruise r.p.m. rather than the low pitch takeoff position, and concluded the pilot neglected to change the setting prior to takeoff.

The Board also examined the flight path. Clarksburg Airport is located in hilly country, with hills rising 273 feet above the runway to the east. To the left of the takeoff direction lies a valley with no obstructions higher than fifty feet for two miles. The company's Operational Manual required a left turn or a straight course when taking off from Runway 5. No waiver had been requested from the Civil Aeronautics Administration to deviate from this procedure, and other pilots stated a right turn from this runway would be extremely hazardous due to the rapidly rising terrain.

**Probable cause** The Board determines that the probable cause of this accident was "the pilot's action in making a takeoff with the propeller set in the cruise position, which precipitated a stall and loss of control of the aircraft while executing a steep right turn to avoid high terrain."