Narrative:

While at FL370 between vixon and 50W, czqx cleared us to be at FL390 by AA12Z. We planned to begin our climb from FL370 at AA08Z. Because of radio calls, we missed our planned climb time of AA08Z and did not begin climb until AA10Z. Gander radio asked us to return to the previous frequency. Upon return, gander noted that we had missed our crossing time and to cross 50W at FL390. We informed them that we were now at FL390 (AA15Z) and gander advised us to contact gander radio again. We had based our climb time on the aircraft weight and turbulence we were encountering. However, due to the late start to climb and our weight we missed the crossing time of AA12 -- should have been more conservative in planning our time to begin climb. Supplemental information from acn 338010: I briefed to climb at AA08Z.

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Original NASA ASRS Text

Title: ALTDEV ALT XING RESTR NOT MET UNDERSHOT IN CLB. OVERWATER OP, WDB ACFT DELAYED CLB TO NEXT ALT. CTLR HAS SHORT TALK WITH CREW.

Narrative: WHILE AT FL370 BTWN VIXON AND 50W, CZQX CLRED US TO BE AT FL390 BY AA12Z. WE PLANNED TO BEGIN OUR CLB FROM FL370 AT AA08Z. BECAUSE OF RADIO CALLS, WE MISSED OUR PLANNED CLB TIME OF AA08Z AND DID NOT BEGIN CLB UNTIL AA10Z. GANDER RADIO ASKED US TO RETURN TO THE PREVIOUS FREQ. UPON RETURN, GANDER NOTED THAT WE HAD MISSED OUR XING TIME AND TO CROSS 50W AT FL390. WE INFORMED THEM THAT WE WERE NOW AT FL390 (AA15Z) AND GANDER ADVISED US TO CONTACT GANDER RADIO AGAIN. WE HAD BASED OUR CLB TIME ON THE ACFT WT AND TURB WE WERE ENCOUNTERING. HOWEVER, DUE TO THE LATE START TO CLB AND OUR WT WE MISSED THE XING TIME OF AA12 -- SHOULD HAVE BEEN MORE CONSERVATIVE IN PLANNING OUR TIME TO BEGIN CLB. SUPPLEMENTAL INFO FROM ACN 338010: I BRIEFED TO CLB AT AA08Z.

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.