Narrative:

We were on an initial climb out from airport which included departing runway 22, a right turn to 360 degrees, and climb and maintain 3000 ft. Departure gave a further right turn to a southeast heading and a further climb clearance to what we thought was 15000 ft. Captain read back heading and 15000 ft ('one five thousand') and set 15000 ft in the altitude alerter. Around 8000 ft, departure asked our altitude, which captain reported as 8000 ft. Controller replied we were only cleared to '5000 ft,' then he instructed us to maintain 8000 ft. Captain correctly informed controller that he read back 'one five thousand.' soon after we were handed off to ZOB. It appears this was a classic case of a readback/hearback error. Captain and I both firmly believe we heard a clearance to 15000 ft. Captain did read back 15000 ft. I think a solution would be to encourage all pilots and controllers to confirm altitude assignments in the teens very carefully. For example: 'climb and maintain one five thousand, fifteen thousand ft.' when I am acting as PNF, I strive to do this with every transmission.

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Original NASA ASRS Text

Title: CPRP MDT FLC HAS PROB WITH CLB CLRNC. BOTH PLTS BELIEVE ATC CLRED TO 15000 FT AND READ BACK THIS ALT. PASSING 8000 FT, CTLR SAYS HE CLRED TO ONLY TO 5000 FT.

Narrative: WE WERE ON AN INITIAL CLBOUT FROM ARPT WHICH INCLUDED DEPARTING RWY 22, A R TURN TO 360 DEGS, AND CLB AND MAINTAIN 3000 FT. DEP GAVE A FURTHER R TURN TO A SE HDG AND A FURTHER CLB CLRNC TO WHAT WE THOUGHT WAS 15000 FT. CAPT READ BACK HDG AND 15000 FT ('ONE FIVE THOUSAND') AND SET 15000 FT IN THE ALT ALERTER. AROUND 8000 FT, DEP ASKED OUR ALT, WHICH CAPT RPTED AS 8000 FT. CTLR REPLIED WE WERE ONLY CLRED TO '5000 FT,' THEN HE INSTRUCTED US TO MAINTAIN 8000 FT. CAPT CORRECTLY INFORMED CTLR THAT HE READ BACK 'ONE FIVE THOUSAND.' SOON AFTER WE WERE HANDED OFF TO ZOB. IT APPEARS THIS WAS A CLASSIC CASE OF A READBACK/HEARBACK ERROR. CAPT AND I BOTH FIRMLY BELIEVE WE HEARD A CLRNC TO 15000 FT. CAPT DID READ BACK 15000 FT. I THINK A SOLUTION WOULD BE TO ENCOURAGE ALL PLTS AND CTLRS TO CONFIRM ALT ASSIGNMENTS IN THE TEENS VERY CAREFULLY. FOR EXAMPLE: 'CLB AND MAINTAIN ONE FIVE THOUSAND, FIFTEEN THOUSAND FT.' WHEN I AM ACTING AS PNF, I STRIVE TO DO THIS WITH EVERY XMISSION.

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.