A PC12 pilot inadvertently entered a building thunderstorm despite the use of weather radar and a di...

Attributes
ACN	945977
Time
Date	201104
Local Time Of Day	1201-1800
Place
Locale Reference	ZFW.ARTCC
State Reference	TX
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	PC-12
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 120 Flight Crew Total 3300 Flight Crew Type 12
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence

Narrative:

Enroute on a reposition flight the aircraft I was piloting flew into a building cumulonimbus. Weather radar was in use as was nexrad weather. Weather was building to the east of my position; and it was visible from the cockpit. The plan to avoid the weather was to continue on a direct course and then deviate west between cells to avoid the weather that was building; as the cell tops were clearly visible from the cockpit. The cells formed a solid line; and continued to build below the aircraft; which I could not see. After entering what I thought was a thin layer; it soon became apparent I was in the top of the building cell. I had been cleared to deviate left and right of course as needed. The aircraft immediately climbed almost 1;800 ft. In an effort to maintain positive flight attitude; I disengaged the autopilot during the turbulence. The aircraft banked hard right; and descended almost 3;400 ft. During the encounter; the aircraft continued a turn to the right until I eventually found a hole to exit the storm. I believe there was a gain of 1;800 ft above assigned altitude and a loss of nearly 1;600 ft below assigned altitude. At one point during the encounter; I was cleared to maintain whatever altitude I could. After exiting the weather; the flight continued to the destination airport without further problems.

Original NASA ASRS Text

Title: A PC12 pilot inadvertently entered a building thunderstorm despite the use of weather radar and a digital weather display system. Loss of control and extended altitude deviations ensued.

Narrative: Enroute on a reposition flight the aircraft I was piloting flew into a building cumulonimbus. Weather radar was in use as was nexrad weather. Weather was building to the east of my position; and it was visible from the cockpit. The plan to avoid the weather was to continue on a direct course and then deviate west between cells to avoid the weather that was building; as the cell tops were clearly visible from the cockpit. The cells formed a solid line; and continued to build below the aircraft; which I could not see. After entering what I thought was a thin layer; it soon became apparent I was in the top of the building cell. I had been cleared to deviate left and right of course as needed. The aircraft immediately climbed almost 1;800 FT. In an effort to maintain positive flight attitude; I disengaged the autopilot during the turbulence. The aircraft banked hard right; and descended almost 3;400 FT. During the encounter; the aircraft continued a turn to the right until I eventually found a hole to exit the storm. I believe there was a gain of 1;800 FT above assigned altitude and a loss of nearly 1;600 FT below assigned altitude. At one point during the encounter; I was cleared to maintain whatever altitude I could. After exiting the weather; the flight continued to the destination airport without further problems.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.