Flight crew of light transport aircraft encounters thunderstorm related turbulence while at cruise.

Attributes
ACN	436178
Time
Date	199905
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zkc.artcc
State Reference	KS
Altitude	msl bound lower : 38700 msl bound upper : 39600
Environment
Flight Conditions	IMC
Weather Elements	Turbulence Ice Windshear
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc.artcc
Operator	general aviation : corporate
Operating Under FAR Part	Part 119
Navigation In Use	Other
Flight Phase	cruise : level
Route In Use	enroute other
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : atp pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 3125 flight time type : 250
ASRS Report	436178
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : turbulence inflight encounter : weather inflight encounter other non adherence : published procedure
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : exited adverse environment
Supplementary
Problem Areas	Flight Crew Human Performance Weather
Primary Problem	Flight Crew Human Performance

Narrative:

While in cruise at FL390, we encountered severe turbulence. The entire episode lasted less than 1 min from start to finish. The captain determined with radar that we would top the large rain cell ahead. When she determined we had passed the cell, she gave a PIREP to ATC. About 2 mins later, the following things happened: airspeed increased from mach 0.80 to mach 0.86, temperature decreased from its previous reading of -20 degrees C, we encountered moderate icing, and altitude fluctuated from approximately FL396 to FL387. Positive aircraft control was maintained throughout the episode. After this, we reported what had happened to ATC. Our experience may have been avoided if we had altered course to avoid the cell and all of its associated adverse WX conditions.

Original NASA ASRS Text

Title: FLC OF LTT ACFT ENCOUNTERS TSTM RELATED TURB WHILE AT CRUISE.

Narrative: WHILE IN CRUISE AT FL390, WE ENCOUNTERED SEVERE TURB. THE ENTIRE EPISODE LASTED LESS THAN 1 MIN FROM START TO FINISH. THE CAPT DETERMINED WITH RADAR THAT WE WOULD TOP THE LARGE RAIN CELL AHEAD. WHEN SHE DETERMINED WE HAD PASSED THE CELL, SHE GAVE A PIREP TO ATC. ABOUT 2 MINS LATER, THE FOLLOWING THINGS HAPPENED: AIRSPD INCREASED FROM MACH 0.80 TO MACH 0.86, TEMP DECREASED FROM ITS PREVIOUS READING OF -20 DEGS C, WE ENCOUNTERED MODERATE ICING, AND ALT FLUCTUATED FROM APPROX FL396 TO FL387. POSITIVE ACFT CTL WAS MAINTAINED THROUGHOUT THE EPISODE. AFTER THIS, WE RPTED WHAT HAD HAPPENED TO ATC. OUR EXPERIENCE MAY HAVE BEEN AVOIDED IF WE HAD ALTERED COURSE TO AVOID THE CELL AND ALL OF ITS ASSOCIATED ADVERSE WX CONDITIONS.

Data retrieved from NASA's ASRS site as of July 2007 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.