ERA17FA017 · Piper PA28 161

The commercial pilot and two student pilot passengers were conducting an instrument flight rules (IFR) flight. The accident airplane was part of a group of several airplanes from the same flying club. About 2 hours 50 minutes after takeoff, the air traffic controller advised the accident pilot of areas of precipitation along the airplane's route of flight; the flight subsequently diverted west for about 6 minutes before re-establishing its northwesterly course.

Review of weather information indicated that the airplane subsequently passed through an area of light-to-heavy rain with severe turbulence, updrafts and downdrafts, and small hail; temperatures at the airplane's cruise altitude were above freezing. The airplane entered a right turn at its cruise altitude; shortly thereafter, the turn rate increased, and the airplane began to rapidly descend. Radar contact was lost, and the airplane was subsequently located in a heavily wooded area. Examination of the airplane revealed no evidence of preimpact failure or malfunction of the airframe, flight controls, or engine. The significant fragmentation of the wreckage was consistent with a high-energy impact following a loss of control.

Although components of the vacuum-operated attitude indicator and directional gyro exhibited rotational scoring, examination of the engine-driven vacuum pump could not determine whether it was operating at impact. The initial right turn, which was about standard rate, was likely the pilot's attempt to fly out of the adverse weather. The subsequent right turn, at greater than standard rate, was likely due to spatial disorientation in adverse instrument conditions and not the result of a vacuum system malfunction.

The weather encountered during the flight was forecast, but the extent to which the pilot had familiarized himself with the weather conditions before the flight could not be determined, because there was no record of the pilot receiving a weather briefing from an official, access-controlled source. Although the pilot had recently completed an instrument proficiency check (IPC), recovery from unusual attitudes was not a requirement of the IPC. None of his instrument flight experience was conducted in actual instrument conditions, and his most recent night flight experience was about 10 months before the accident.

While the pilot was expecting weather avoidance assistance from the pilot of another airplane based on their verbal agreement before departure, the two pilots did not communicate during the accident flight. Given that the accident airplane was not equipped with onboard weather information, it could not be determined why the pilot chose to deviate in the direction that he did, rather than asking the controller for more information regarding the weather or for assistance in deviating around it. If the pilot had requested assistance, the controller likely would have been able to provide him with vectors to avoid the adverse conditions.

Verbatim NTSB analysis and probable cause from the NTSB dataset