NTSB Identification: CHI07LA035.
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Accident occurred Sunday, December 03, 2006 in Atlanta, GA
Probable Cause Approval Date: 01/31/2008
Aircraft: Piper PA 46-350P, registration: N46PT
Injuries: 2 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot reported that he heard a loud whistling noise while in level cruise at flight level (FL) 220 and noticed that the right side attitude indicator was "tilted." While he was leaning over adjusting the instrument, he realized that the airplane was in a dive. He leveled the wings and pulled out of the dive at FL 190. The autopilot (A/P) was re-engaged and the flight was completed to its intended destination without further incident. A visual examination after the descent revealed the left front baggage door open and buckled, and the left and right wings showed skin damage and wrinkling approximately 54 inches from the wing roots. When tested, the autopilot and flight director performed within test specifications with only "minor" deviations. Both vacuum pumps tested within test specifications. The right side attitude indicator continued to show a three degree turn even after a kink in the vacuum supply to the right side attitude indicator was removed. The "normal" static system leaked in excess of allowable limits; however, the valve was found to be in the "alternate" position before it was tested. An active noise-canceling set of headphones was found connected to the pilot's side of the cockpit. The A/P disconnect tone was found to be operating normally while the engine was at idle power. During the test, it was noted that the tone was difficult to hear while wearing the headset.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

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. An additional cause was the aural detection for the autopilot disconnect was difficult to hear with the noise canceling headset. A contributing factor was the disengaged autopilot/flight director.

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