On December 3, 2006, a Piper PA 46-350P (registration N46PT) was involved in an aviation accident near Atlanta, GA. Investigators recorded the probable cause as: The exceedance of airplane design stress limits when the pilot did not maintain aircraft control after his attention was diverted to the right side attitude indicator during cruise flight. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported a loud whistling noise at FL220 and a tilted attitude indicator, realizing the aircraft was in a dive. After recovery at FL190, the flight continued. Post-flight inspection revealed an open baggage door and wing skin damage.
Incident Description
During a flight at flight level (FL) 220, the pilot reported hearing a loud whistling noise. The right side attitude indicator appeared tilted. While the pilot leaned over to adjust the instrument, he noticed the aircraft was in a dive. He leveled the wings and pulled out of the dive at FL 190. The autopilot was re-engaged, and the flight proceeded to its intended destination without further incident.
Post-Flight Inspection
A visual examination after the descent revealed that the left front baggage door was open and buckled. Both the left and right wings exhibited skin damage and wrinkling approximately 54 inches from the wing roots.
System Tests
Subsequent testing showed that the autopilot and flight director performed within test specifications, with only minor deviations. Both vacuum pumps were also within test specifications. The right side attitude indicator continued to show a three-degree turn even after a kink in the vacuum supply to that indicator was removed. The normal static system leaked in excess of allowable limits, but the valve was found in the alternate position before testing. An active noise-canceling headset was found connected to the pilot's side of the cockpit. The autopilot disconnect tone operated normally at idle power, though it was noted as difficult to hear while wearing the headset.