Summary
An airplane carrying 10 sport parachutists and one pilot crashed after experiencing engine misfire during takeoff. Investigators determined that the aircraft's maximum gross weight was exceeded by 149.6 pounds, and the center of gravity was 2.87 inches aft of the aft limit. The cabin door had been removed without proper FAA authorization, relying on an altered Flight Manual Supplement. Fueling irregularities were noted, and a right engine shutdown occurred prior to impact. One person in a residence was killed.
Sequence of Events
Before takeoff, samples of fuel were drained from the airplane's fuel sumps. During takeoff, witnesses reported hearing an engine misfiring. The airplane leveled off during initial climb and began a shallow right turn. The bank angle increased progressively from shallow to steep as the nose dropped and the airplane descended. Other witnesses observed the airplane in a steep dive moments before it crashed into the rear of a residence. A postaccident fire destroyed the accessory sections of both engines.
Weight and Balance
Examination of the loading revealed that the maximum gross weight was exceeded by 149.6 pounds, and the center of gravity was 2.87 inches aft of the aft limit. Additionally, the cabin door had been removed for parachuting operations, but the airplane was not on the FAA-approved eligible list for door removal. An altered Flight Manual Supplement was used as authority for the removal.
Fueling
The airplane required refueling prior to flight. However, the fuel quantity in the airport's underground storage tank was below the electric cutoff level. Fuel was manually pumped from the storage tank into plastic jugs, which were then used to refuel the aircraft. A sample of excess fuel obtained from the tank used showed no observable quantity of water or contamination.
Engine Examination
Examination of the airplane disclosed evidence that the right engine had been shut down and the right propeller feathered. No preimpact mechanical failure was found in either engine. The cause of the right engine power loss was not determined.
Probable Cause (Official Findings)
The pilot's inadequate preflight/preparation, his failure to ensure proper weight and balance of the airplane, and his failure to obtain/maintain minimum control speed, which resulted in a loss of aircraft control after loss of power in one engine. A factor relating to the accident was: loss of power in the right engine for undetermined reason(s).