A300 airbus flight crew encounters severe turbulence during climb and has an altitude deviation.

Attributes
ACN	717924
Time
Date	200611
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : roc.airport
State Reference	OH
Altitude	msl single value : 23000
Environment
Flight Conditions	IMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc tower : zzz.tower
Operator	common carrier : air carrier
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 100 flight time total : 9000 flight time type : 450
ASRS Report	717924
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : turbulence non adherence : clearance
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Weather Flight Crew Human Performance
Primary Problem	Weather

Narrative:

Departed roc; cleared from 10000 ft to FL230. Passing 15000 ft began experiencing moderate turbulence. Slowed aircraft to 280 KIAS. As we were leveling at FL230 we hit severe turbulence. Reduced airspeed further and came out of profile mode to altitude hold. First officer immediately requested higher altitude. ZOB gave us climb to FL260 and asked current altitude as they showed we had momentarily hit 23600 ft. We could not read the instrument panel so we did not know what altitude we hit. Climbed to FL260 where ride smoothed out. About 2 mins later we were cleared to FL300 and entered severe turbulence again. Before we started climb aircraft lost almost 400 ft within 1 second. Center did not question us on that deviation. I am sure we were not holding altitude during the severe turbulence. Have not been in turbulence quite that severe and don't want to again. It was impossible to hold or to read altitude.

Original NASA ASRS Text

Title: A300 AIRBUS FLT CREW ENCOUNTERS SEVERE TURB DURING CLB AND HAS AN ALTDEV.

Narrative: DEPARTED ROC; CLRED FROM 10000 FT TO FL230. PASSING 15000 FT BEGAN EXPERIENCING MODERATE TURB. SLOWED ACFT TO 280 KIAS. AS WE WERE LEVELING AT FL230 WE HIT SEVERE TURB. REDUCED AIRSPD FURTHER AND CAME OUT OF PROFILE MODE TO ALT HOLD. FO IMMEDIATELY REQUESTED HIGHER ALT. ZOB GAVE US CLB TO FL260 AND ASKED CURRENT ALT AS THEY SHOWED WE HAD MOMENTARILY HIT 23600 FT. WE COULD NOT READ THE INST PANEL SO WE DID NOT KNOW WHAT ALT WE HIT. CLBED TO FL260 WHERE RIDE SMOOTHED OUT. ABOUT 2 MINS LATER WE WERE CLRED TO FL300 AND ENTERED SEVERE TURB AGAIN. BEFORE WE STARTED CLB ACFT LOST ALMOST 400 FT WITHIN 1 SECOND. CTR DID NOT QUESTION US ON THAT DEV. I AM SURE WE WERE NOT HOLDING ALT DURING THE SEVERE TURB. HAVE NOT BEEN IN TURB QUITE THAT SEVERE AND DON'T WANT TO AGAIN. IT WAS IMPOSSIBLE TO HOLD OR TO READ ALT.

Data retrieved from NASA's ASRS site as of January 2009 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.