Narrative:

While climbing we were assigned FL210 by center. After climbing passt FL205, we were asked what altitude we were assigned. We told them FL210, and were told to descend to FL190. On TCASII we saw an aircraft 8 mi or so behind us at FL210, and assume that we were supposed to only be cleared to FL190, not FL210. No evasive action required (we are sure that we were cleared to FL210).

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Original NASA ASRS Text

Title: B727-200 HAD ACKNOWLEDGED CLB TO FL210. LEAVING FL205 CTLR QUESTIONED ALT AND ADVISED THE FLT TO DSND TO FL190. NOTED ON TCASII ACFT BEHIND MAINTAINING FL210.

Narrative: WHILE CLBING WE WERE ASSIGNED FL210 BY CTR. AFTER CLBING PASST FL205, WE WERE ASKED WHAT ALT WE WERE ASSIGNED. WE TOLD THEM FL210, AND WERE TOLD TO DSND TO FL190. ON TCASII WE SAW AN ACFT 8 MI OR SO BEHIND US AT FL210, AND ASSUME THAT WE WERE SUPPOSED TO ONLY BE CLRED TO FL190, NOT FL210. NO EVASIVE ACTION REQUIRED (WE ARE SURE THAT WE WERE CLRED TO FL210).

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.