Departure and Conditions
The aircraft departed for a cross-country flight in instrument meteorological conditions (IMC). During the climb to cruise altitude, the pilot experienced a loss of aircraft control, which was followed by an inflight separation of both wings and the empennage.
Investigation Findings
Subsequent investigation revealed that ice was blocking the pitot/static tube. Icing forecasts had been valid for the period covering the time of the flight, and the pilot had received a briefing regarding possible ice. The pitot heat system was tested during a post-accident examination and was found to be operational; however, the pitot heat switch was found in the off position after the accident.
Conclusions
The blockage of the pitot/static tube by ice, combined with the pitot heat being off, led to inaccurate airspeed indications. This likely caused the loss of control and subsequent structural failure.