Narrative:

The event occurred while climbing lear jet 35A out of reading, PA. We were handed off to new york center by harrisburg approach at 8000 ft. New york center climbed us to 10000 ft. They then gave us a heading of 360 degrees and a climb to 17000 ft expedite out of 12000 ft. We then were given 330. I understood it as an altitude and set 330 ft in altitude alerter instead of a heading change to 330 degrees. I did not realize there was a problem until center asked us to verify altitude. We replied FL210 climbing to FL330. He then notified us he had only cleared us to 17000 ft. He asked us to level at 220. No conflict arose that we know of. I am not sure whether I read back the 330 clearance as a heading or altitude clearance. I think a factor affecting performance was fatigue due to length of duty day. We made our 1ST departure at early local and had awakened at earlier for this. We were on our 4TH leg of the day at the time of the occurrence. We also were climbing at about 3000 FPM due to light weight, cold air, and expedite clearance. Supplemental information from acn 261923: we were given a climb to 17000 which the PIC in the right seat placed in the altitude select of the autoplt. Shortly thereafter, we were given a turn to a heading of 360 degrees. The next turn was given, again by new york center to 330 degrees. At this point I rotated the heading bug to 330 degrees and continued the climb -- with the rate of climb we had I looked to the altitude select controller and saw that FL330 had been selected in the window. I assumed I had misunderstood the command, and that we were cleared to FL330.

Related reports:

Google
 

Original NASA ASRS Text

Title: ALT BUST.

Narrative: THE EVENT OCCURRED WHILE CLBING LEAR JET 35A OUT OF READING, PA. WE WERE HANDED OFF TO NEW YORK CTR BY HARRISBURG APCH AT 8000 FT. NEW YORK CTR CLBED US TO 10000 FT. THEY THEN GAVE US A HDG OF 360 DEGS AND A CLB TO 17000 FT EXPEDITE OUT OF 12000 FT. WE THEN WERE GIVEN 330. I UNDERSTOOD IT AS AN ALT AND SET 330 FT IN ALT ALERTER INSTEAD OF A HDG CHANGE TO 330 DEGS. I DID NOT REALIZE THERE WAS A PROB UNTIL CTR ASKED US TO VERIFY ALT. WE REPLIED FL210 CLBING TO FL330. HE THEN NOTIFIED US HE HAD ONLY CLRED US TO 17000 FT. HE ASKED US TO LEVEL AT 220. NO CONFLICT AROSE THAT WE KNOW OF. I AM NOT SURE WHETHER I READ BACK THE 330 CLRNC AS A HEADING OR ALT CLRNC. I THINK A FACTOR AFFECTING PERFORMANCE WAS FATIGUE DUE TO LENGTH OF DUTY DAY. WE MADE OUR 1ST DEP AT EARLY LCL AND HAD AWAKENED AT EARLIER FOR THIS. WE WERE ON OUR 4TH LEG OF THE DAY AT THE TIME OF THE OCCURRENCE. WE ALSO WERE CLBING AT ABOUT 3000 FPM DUE TO LIGHT WT, COLD AIR, AND EXPEDITE CLRNC. SUPPLEMENTAL INFO FROM ACN 261923: WE WERE GIVEN A CLB TO 17000 WHICH THE PIC IN THE R SEAT PLACED IN THE ALT SELECT OF THE AUTOPLT. SHORTLY THEREAFTER, WE WERE GIVEN A TURN TO A HDG OF 360 DEGS. THE NEXT TURN WAS GIVEN, AGAIN BY NEW YORK CTR TO 330 DEGS. AT THIS POINT I ROTATED THE HDG BUG TO 330 DEGS AND CONTINUED THE CLB -- WITH THE RATE OF CLB WE HAD I LOOKED TO THE ALT SELECT CTLR AND SAW THAT FL330 HAD BEEN SELECTED IN THE WINDOW. I ASSUMED I HAD MISUNDERSTOOD THE COMMAND, AND THAT WE WERE CLRED TO FL330.

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.