Aircraft: Bellanca Viking. Injuries: 2 Fatal. Location: Rock Springs, Wyo. Aircraft damage: Destroyed.
What reportedly happened: The private pilot did not have an instrument rating. According to his logbook he had accumulated about 3,040 flying hours, including 1,330 hours in a Bellanca. The pilot’s initial plan was to make the cross-country flight on the day before the accident flight actually took place. The pilot decided to postpone the flight until the next day because of poor weather.
During the weather briefing the pilot interrupted the briefer, saying that he had a copy of the Terminal Area Forecast in front of him, and that he needed to learn to read it. Then, for about a minute and a half, the pilot asked the briefer questions about what specific numbers, letters, and abbreviations on the TAF meant.
The weather briefer advised the pilot that the adverse conditions would still be present along the route of flight the next day, including areas of clouds, low ceilings, precipitation, icing conditions, snow, and thunderstorms. There was no record of the pilot obtaining a briefing on the day of the flight.
Overlaying the airplane’s radar track on weather radar imagery indicated that, about 30 minutes after departure, the pilot encountered an area of precipitation where supercooled liquid droplets had been forecast. This most likely resulted in a very rapid accumulation of ice on the airplane. Soon thereafter, the airplane entered a steep uncontrolled descent, during which the outboard section of the right wing separated as it was stressed beyond the design limitations of the airplane. The airplane continued in a near vertical uncontrolled descent and impacted the terrain with a high amount of energy.
Post-accident examination of the airframe, flight controls, and the engine did not find any evidence of a pre-existing anomaly.
Probable cause: The pilot’s decision to continue flight into an area of known adverse weather, which resulted in an accumulation of structural ice that led to a loss of control and in-flight breakup. Also causal was the pilot’s inadequate preflight weather planning.
NTSB Identification: WPR11FA228
This May 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.