Narrative:

While flying eastbound at FL330, we encountered light turbulence which became occasional moderate. We inquired about ride reports at FL370 and were told it was reported smooth at that altitude. We requested FL370. The controller said he had our request and would 'work it out.' a short time later we were given a frequency change to 135.32 and told the next controller had our request for FL370. Because the turbulence was increasing in intensity, I checked in and requested FL370. A short time later we were given a heading change for 'traffic in your climb' and I thought cleared to FL370. It is possible that we were cleared to FL350 and that I read back FL350 along with the new heading. I just don't know. The fact is I set FL370 in the altitude alerter and verbally coordinated a climb to FL370 with the PF. In the climb while approaching FL360, the controller asked 'do you know you were cleared to FL350?' the PF had just begun a correction to FL350 when the controller said 'climb and maintain FL370 I may have to give you another heading change for traffic.' we climbed to FL370 and shortly after level off were given another heading change. The rest of the flight proceeded without incident. Such things as fatigue or workload were not factors in this situation. If the incident was our fault, it was because we had 'FL370 on the brain' and we were anxious to exit the turbulence. FL350 was not a consideration in our request because it was the wrong altitude for direction of flight. In any case we have both reemphasized to ourselves to listen closely to clrncs especially during turbulence or other abnormal flight conditions.

Related reports:

Google
 

Original NASA ASRS Text

Title: ALTDEV ALT OVERSHOT IN CLB.

Narrative: WHILE FLYING EBOUND AT FL330, WE ENCOUNTERED LIGHT TURB WHICH BECAME OCCASIONAL MODERATE. WE INQUIRED ABOUT RIDE RPTS AT FL370 AND WERE TOLD IT WAS RPTED SMOOTH AT THAT ALT. WE REQUESTED FL370. THE CTLR SAID HE HAD OUR REQUEST AND WOULD 'WORK IT OUT.' A SHORT TIME LATER WE WERE GIVEN A FREQ CHANGE TO 135.32 AND TOLD THE NEXT CTLR HAD OUR REQUEST FOR FL370. BECAUSE THE TURB WAS INCREASING IN INTENSITY, I CHKED IN AND REQUESTED FL370. A SHORT TIME LATER WE WERE GIVEN A HDG CHANGE FOR 'TFC IN YOUR CLB' AND I THOUGHT CLRED TO FL370. IT IS POSSIBLE THAT WE WERE CLRED TO FL350 AND THAT I READ BACK FL350 ALONG WITH THE NEW HDG. I JUST DON'T KNOW. THE FACT IS I SET FL370 IN THE ALT ALERTER AND VERBALLY COORDINATED A CLB TO FL370 WITH THE PF. IN THE CLB WHILE APCHING FL360, THE CTLR ASKED 'DO YOU KNOW YOU WERE CLRED TO FL350?' THE PF HAD JUST BEGUN A CORRECTION TO FL350 WHEN THE CTLR SAID 'CLB AND MAINTAIN FL370 I MAY HAVE TO GIVE YOU ANOTHER HDG CHANGE FOR TFC.' WE CLBED TO FL370 AND SHORTLY AFTER LEVEL OFF WERE GIVEN ANOTHER HDG CHANGE. THE REST OF THE FLT PROCEEDED WITHOUT INCIDENT. SUCH THINGS AS FATIGUE OR WORKLOAD WERE NOT FACTORS IN THIS SIT. IF THE INCIDENT WAS OUR FAULT, IT WAS BECAUSE WE HAD 'FL370 ON THE BRAIN' AND WE WERE ANXIOUS TO EXIT THE TURB. FL350 WAS NOT A CONSIDERATION IN OUR REQUEST BECAUSE IT WAS THE WRONG ALT FOR DIRECTION OF FLT. IN ANY CASE WE HAVE BOTH REEMPHASIZED TO OURSELVES TO LISTEN CLOSELY TO CLRNCS ESPECIALLY DURING TURB OR OTHER ABNORMAL FLT 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.