Executive/Corporate/Business

The pilot's spatial disorientation resulting in a loss of control and collision with the ground. Additional factors included the pilot operating the airplane with known deficiencies and the instrument flight conditions.

The pilot's mismanagement of fuel, which resulted in a total loss of engine power due to fuel starvation. Contributing factors were the pilot's failure to follow the checklist to feather the propellers in order to reduce drag.

The pilot's failure to maintain control of the airplane, due to spatial disorientation, while performing a missed approach, resulting in an uncontrolled descent, and subsequent impact with a tree and a house. Factors in this accident were dark night, fog, drizzle, the pilot's lack of total instrument time, and his lack of total experience in this type of aircraft.

The pilot's failure to discontinue the approach after encountering instrument meteorological conditions, which resulted in controlled flight into terrain. Contributing factors were the dark night light condition, low ceiling, and reduced visibility due to fog.

The inadequate planning/decision and the exceeded crosswind component by the pilot. The gusts were a contributing factor.

The pilot's failure to refuel the airplane, which resulted in fuel exhaustion and subsequent loss of dual engine power while on approach.

While in cruising altitude, the crew encountered severe updrafts while flying in thunderstorm activity. Following a possible abrupt and abnormal manoeuvre, the crew lost control of the airplane that entered a spiral dive, resulting in an in-flight break up due to aerodynamic overload, leading to a total loss of control followed with a heavy impact with the ground.

Findings as to Causes and Contributing Factors:
1. The pilot abandoned his attempt to fly through the pass because of unsuitable weather conditions. He flew into a confined area that required him to manoeuvre the aircraft aggressively to avoid the rising terrain, causing the aircraft to stall.
2. The aircraft weight exceeded the certificated MAUW, and the CG was outside the floatplane aft limit. The out-of-limit weight and balance aggravated aerodynamic stall and produced rapid and
uncontrolled aircraft attitudes from which the pilot could not recover before striking the trees.
3. Basic weight and balance of the aircraft was incorrectly recorded in several aircraft documents, leading to remarkable discrepancies in take-off weight and CG calculations. As a result, a pilot could not calculate an accurate weight and balance. In certain conditions, calculations erroneously showed that the aircraft was below maximum allowable gross weight.
Findings as to Risk:
1. The practice of using a non-standard passenger weight led to inaccurate take-off weight calculations and provided an estimated total passenger weight that was 185 pounds less than actual.
2. Weight and balance calculations performed using inaccurate figures would not have revealed that the aircraft was overloaded until it was approximately 450 pounds beyond the maximum limit.
3. Aircraft weight exceeded the maximum allowable gross weight, and the CG was outside the aft CG limit. This weight and balance combination placed the aircraft outside the manufacturer’s
original design envelope, to where slow speed and stall handling characteristics are neither proven nor certificated.
4. Cargo was not secured by the available cargo restraint and might have shifted during aircraft manoeuvring. Such cargo movement would have exacerbated the effects of the existing aft CG and likely increased the level of injury to the occupants.
Other Findings:
1. The pilot chose to fly above cloud in accordance with the visual flight rules and could not descend through the cloud at his intended landing site.
2. The Alaska cargo door installation increases the volume of the cargo compartment. The installation is thereby conducive to larger loads being stowed farther aft and possible overloading of the cargo compartment.
3. The DHC-2 Beaver is not equipped with an aural or visual stall warning system, nor is it required by regulation. Warning of an impending stall is dependent on juddering or some other aerodynamic indication.

The right main tire blowing out in flight, which resulted in a loss of directional control during landing.

The pilot-in command's failure to maintain airspeed during the approach, resulting in an inadvertent stall and in-flight collision with the terrain during an uncontrollable descent.