Overweight and out of balance

Investigators determined that cargo loaded aboard a de Havilland DHC-3 Otter for an air taxi flight from Soldotna, Alaska, weighed about 418 pounds more than was listed on the load manifest, with fatal consequences.

The July 2013 crash of the Otter operated by Rediske Air has prompted lawsuits, including one filed by the widow of pilot Lyla Rediske against Bear Mountain Lodge, LLC, the flight’s destination, also naming two lodge employees. Families of the nine passengers who were also killed filed a similar suit.

The NTSB determined that the probable cause of the July 7, 2013, crash was “the operator’s failure to determine the actual cargo weight, leading to the loading and operation of the airplane outside of the weight and center of gravity limits … which resulted in an aerodynamic stall.” The board determined that the FAA’s failure to require weight-and-balance documentation for Part 135 single-engine operations was a contributing factor.

Investigators recovered video of the taxi and takeoff recorded by a passenger looking out a window on the left side, and determined that the airplane’s angle of attack increased continually and airspeed decayed after liftoff, dropping from about 68 mph to 44 mph over 8.5 seconds. The Otter stalled about 11 seconds after liftoff, rolled to the right, and struck the ground.

Investigators recovered cargo from the crash site and determined the weight of additional cargo destroyed in the post-crash fire to calculate the aircraft’s load, and found that the extra weight also put the airplane’s center of gravity beyond the aft limit. Investigators determined that the aircraft was uncontrollable, and while the flaps were set for landing (fully extended), rather than for takeoff, "the CG was so far aft of the limit that the airplane likely would have stalled even with the flaps in the correct position,” the report states.