Narrative:

During initial climb out of yip, we were cleared to FL240. I received a clearance to FL250, set FL250 in the altitude select, and read back that I was going to maintain FL250. (At this time the autoplt was engaged and I was working the radios due to the fact that the first officer was involved in putting away charts and verifying rtes and frequencys.) I received a frequency change from ATC. I checked in with ZOB and stated that I was passing FL180 for FL250. I was told I was still with the lower guy. I apologized and said I must have forgot to push the button. I then pressed the FLIP-flop switch and stated to ZOB that I was passing FL190 for FL250. Center acknowledged and stated nothing further. Shortly after the check on, the first officer was back to making the radio calls. We received a TA from TCASII and started searching for a visual on the traffic. As the first officer spotted the traffic we received an RA from TCASII telling us to 'decrease climb.' I stopped the climb at FL242, just as I heard the controller say that it looked like someone didn't level off. I asked the first officer to confirm our altitude cleared to, and ATC said it was FL240 and asked what we were last cleared to. The first officer relayed that I said it was FL250 and that I had stated so when checking in. ATC said no, it was FL240. By this time I was back down to FL240 and leveled off. To the best of my knowledge, the other traffic had not received any warning and was unaware of the situation until we asked center to verify our altitude clearance.

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Original NASA ASRS Text

Title: BAE125 CREW RECEIVED TCASII RA CLBING TO FL250.

Narrative: DURING INITIAL CLB OUT OF YIP, WE WERE CLRED TO FL240. I RECEIVED A CLRNC TO FL250, SET FL250 IN THE ALT SELECT, AND READ BACK THAT I WAS GOING TO MAINTAIN FL250. (AT THIS TIME THE AUTOPLT WAS ENGAGED AND I WAS WORKING THE RADIOS DUE TO THE FACT THAT THE FO WAS INVOLVED IN PUTTING AWAY CHARTS AND VERIFYING RTES AND FREQS.) I RECEIVED A FREQ CHANGE FROM ATC. I CHKED IN WITH ZOB AND STATED THAT I WAS PASSING FL180 FOR FL250. I WAS TOLD I WAS STILL WITH THE LOWER GUY. I APOLOGIZED AND SAID I MUST HAVE FORGOT TO PUSH THE BUTTON. I THEN PRESSED THE FLIP-FLOP SWITCH AND STATED TO ZOB THAT I WAS PASSING FL190 FOR FL250. CTR ACKNOWLEDGED AND STATED NOTHING FURTHER. SHORTLY AFTER THE CHK ON, THE FO WAS BACK TO MAKING THE RADIO CALLS. WE RECEIVED A TA FROM TCASII AND STARTED SEARCHING FOR A VISUAL ON THE TFC. AS THE FO SPOTTED THE TFC WE RECEIVED AN RA FROM TCASII TELLING US TO 'DECREASE CLB.' I STOPPED THE CLB AT FL242, JUST AS I HEARD THE CTLR SAY THAT IT LOOKED LIKE SOMEONE DIDN'T LEVEL OFF. I ASKED THE FO TO CONFIRM OUR ALT CLRED TO, AND ATC SAID IT WAS FL240 AND ASKED WHAT WE WERE LAST CLRED TO. THE FO RELAYED THAT I SAID IT WAS FL250 AND THAT I HAD STATED SO WHEN CHKING IN. ATC SAID NO, IT WAS FL240. BY THIS TIME I WAS BACK DOWN TO FL240 AND LEVELED OFF. TO THE BEST OF MY KNOWLEDGE, THE OTHER TFC HAD NOT RECEIVED ANY WARNING AND WAS UNAWARE OF THE SIT UNTIL WE ASKED CTR TO VERIFY OUR ALT CLRNC.

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.