Beech 36 N408P accident near Spring Branch, Texas

Probable cause

The pilot's inadequate preflight performance planning and his operation of the airplane outside of the manufacturer's specified weight and balance limitations, which resulted in a failure of the airplane to become airborne, an aborted takeoff, and subsequent runway excursion.

NTSB analysis

The pilot stated that, during takeoff, the engine sounded normal, but when he tried to rotate the airplane at a speed of about 80 knots, the airplane would not fly, and he felt it "shudder." He then reduced the engine power to abort the takeoff and maneuvered the airplane into the grass to slow it down, resulting in substantial damage to both wings.

The pilot stated that he was unaware of the density altitude at the time of departure and also stated that he used 2,100 lbs for the basic empty weight of the airplane when calculating the takeoff weight and did not think the airplane was close to its maximum gross weight. Review of the airplane's most recent weight and balance information revealed a basic empty weight of 2,623.34 lbs. When combined with the cargo weight, the weights of the pilot and four passengers, and the fuel load, the airplane was about 231 lbs over its maximum takeoff weight at the time of the accident.

A review of the manufacturer's supplied flaps-retracted takeoff distance chart located in the pilot's operating handbook revealed that the airplane's weight at the time of the accident exceeded the chart's performance parameters. Additionally, the data provided did not include penalties or enhancements for sloped runways (the runway had 1.4° upslope). The pilot's failure to obtain the correct weight and balance information for the airplane resulted in his operation of the airplane outside of its limitations and the airplane's inability to take off in the available runway and a subsequent runway excursion.

Text from the NTSB. Open the NTSB docket for CEN20TA031 for the full record.