Flight crew of large transport encountered turbulence at FL370. Lost 500' altitude.

Attributes
ACN	180398
Time
Date	199106
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sps
State Reference	TX
Altitude	msl bound lower : 36500 msl bound upper : 37000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 230 flight time total : 7000 flight time type : 230
ASRS Report	180398
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Around wichita falls, a line of thunderstorms were developing with 20-30 mi range between cells. We were circumnaving using our c-band black and white radar. Radar showed us transiting between cells when we were hit with heavy rain and severe turbulence. We were in the clouds at the time, altitude lost was 500'. The entire incident lasted about 20 seconds. We returned to 37000' in the clear. There were no injuries or damages.

Original NASA ASRS Text

Title: FLT CREW OF LGT ENCOUNTERED TURBULENCE AT FL370. LOST 500' ALT.

Narrative: AROUND WICHITA FALLS, A LINE OF TSTMS WERE DEVELOPING WITH 20-30 MI RANGE BTWN CELLS. WE WERE CIRCUMNAVING USING OUR C-BAND BLACK AND WHITE RADAR. RADAR SHOWED US TRANSITING BTWN CELLS WHEN WE WERE HIT WITH HEAVY RAIN AND SEVERE TURB. WE WERE IN THE CLOUDS AT THE TIME, ALT LOST WAS 500'. THE ENTIRE INCIDENT LASTED ABOUT 20 SECS. WE RETURNED TO 37000' IN THE CLR. THERE WERE NO INJURIES OR DAMAGES.

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.