L1011 crew experiences turbulence and deviates from assigned altitude in ZME airspace.

Attributes
ACN	428155
Time
Date	199902
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zme.artcc
State Reference	TN
Altitude	msl bound lower : 32600 msl bound upper : 33400
Environment
Flight Conditions	IMC
Weather Elements	Thunderstorm Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme.artcc tower : sus.tower
Operator	common carrier : air carrier
Make Model Name	L-1011 Tri-Star All Series
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : multi engine pilot : atp pilot : commercial
Experience	flight time last 90 days : 180 flight time total : 26000 flight time type : 6000
ASRS Report	428155
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather inflight encounter : turbulence non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : exited adverse environment flight crew : regained aircraft control
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Weather
Air Traffic Incident	other

Narrative:

Approaching a well defined front, asked ATC to climb above cloud tops (FL370). Asked for turbulence report, and center reported 'light turbulence.' after entering scattered line of cumulo nimbus in IMC, encountered mountain wave, causing aircraft to lose and gain 400 ft from assigned altitude. Severity caused autoplt to disengage and we recovered back to assigned altitude. Center questioned altitude deviation and that there was conflicting traffic. ATC was so busy we could not get meaningful information or transmit a PIREP until well after the event. I believe controller was overloaded in his sector and unable to be more flexible with altitudes considering WX conditions.

Original NASA ASRS Text

Title: L1011 CREW EXPERIENCES TURB AND DEVIATES FROM ASSIGNED ALT IN ZME AIRSPACE.

Narrative: APCHING A WELL DEFINED FRONT, ASKED ATC TO CLB ABOVE CLOUD TOPS (FL370). ASKED FOR TURB RPT, AND CTR RPTED 'LIGHT TURB.' AFTER ENTERING SCATTERED LINE OF CUMULO NIMBUS IN IMC, ENCOUNTERED MOUNTAIN WAVE, CAUSING ACFT TO LOSE AND GAIN 400 FT FROM ASSIGNED ALT. SEVERITY CAUSED AUTOPLT TO DISENGAGE AND WE RECOVERED BACK TO ASSIGNED ALT. CTR QUESTIONED ALTDEV AND THAT THERE WAS CONFLICTING TFC. ATC WAS SO BUSY WE COULD NOT GET MEANINGFUL INFO OR XMIT A PIREP UNTIL WELL AFTER THE EVENT. I BELIEVE CTLR WAS OVERLOADED IN HIS SECTOR AND UNABLE TO BE MORE FLEXIBLE WITH ALTS CONSIDERING 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.