Narrative:

On a revenue flight from nashville, tn, to orlando, fl, I was the PF, captain was handling radios. We were cruising at FL310. ZJX gave us clearance to valdosta VORTAC, then the lessee arrival to orlando international. Outside of valdosta, controller gave us a descent clearance to cross valdosta at FL240. Captain read back clearance and put FL240 into altitude box. I didn't hear the controller clearly enough, but the captain confirmed FL240 by pointing to altitude preselector, and I pointed to it (company procedure). I initiated the descent. Passing FL260 the controller said 'your clearance was to FL270.' I started to level off at approximately FL260 and captain told ZJX that he read back FL240. The controller said, 'no, your clearance was to FL270, if you want to descend to FL240 you can, but I gave you clearance to FL270.' I continued descent to FL240. Because I didn't hear the clearance clearly when initially given, I'm 90 percent sure the captain read back FL240 and therefore almost certain the controller gave us FL240. No evasive action was taken, and we continued the arrival, but the controller seemed adamant that he gave us FL270. Had I questioned the initial clearance to the captain or ZJX (because I didn't hear it clearly to begin with), maybe we could have cleared up the confusion.

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Original NASA ASRS Text

Title: CAPT OF AN MDT MISINTERPRETED THE DSCNT XING ALT AND CONSEQUENTLY OVERSHOT IT CAUSING ATC TO INTERVENE AND AMEND THE CLRNC.

Narrative: ON A REVENUE FLT FROM NASHVILLE, TN, TO ORLANDO, FL, I WAS THE PF, CAPT WAS HANDLING RADIOS. WE WERE CRUISING AT FL310. ZJX GAVE US CLRNC TO VALDOSTA VORTAC, THEN THE LESSEE ARR TO ORLANDO INTL. OUTSIDE OF VALDOSTA, CTLR GAVE US A DSCNT CLRNC TO CROSS VALDOSTA AT FL240. CAPT READ BACK CLRNC AND PUT FL240 INTO ALT BOX. I DIDN'T HEAR THE CTLR CLRLY ENOUGH, BUT THE CAPT CONFIRMED FL240 BY POINTING TO ALT PRESELECTOR, AND I POINTED TO IT (COMPANY PROC). I INITIATED THE DSCNT. PASSING FL260 THE CTLR SAID 'YOUR CLRNC WAS TO FL270.' I STARTED TO LEVEL OFF AT APPROX FL260 AND CAPT TOLD ZJX THAT HE READ BACK FL240. THE CTLR SAID, 'NO, YOUR CLRNC WAS TO FL270, IF YOU WANT TO DSND TO FL240 YOU CAN, BUT I GAVE YOU CLRNC TO FL270.' I CONTINUED DSCNT TO FL240. BECAUSE I DIDN'T HEAR THE CLRNC CLRLY WHEN INITIALLY GIVEN, I'M 90 PERCENT SURE THE CAPT READ BACK FL240 AND THEREFORE ALMOST CERTAIN THE CTLR GAVE US FL240. NO EVASIVE ACTION WAS TAKEN, AND WE CONTINUED THE ARR, BUT THE CTLR SEEMED ADAMANT THAT HE GAVE US FL270. HAD I QUESTIONED THE INITIAL CLRNC TO THE CAPT OR ZJX (BECAUSE I DIDN'T HEAR IT CLRLY TO BEGIN WITH), MAYBE WE COULD HAVE CLRED UP THE CONFUSION.

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.