Narrative:

Cruising at FL430 to stay above numerous thunderstorms en route, we were approaching phx from the east. Copilot flying asked captain to obtain descent clearance. We were off arwys at the time, deviating WX, and getting close to phx. When center finally gave us descent clearance they gave us about 25 mi to get down to FL240. Now one thing the widebody transport doesn't do well is come down in a hurry. Knowing the amount of time it takes the computer to figure out a descent profile, and that we were way behind anyway, the copilot disengaged the autoplt and autothrottles and began a descent with full speed brakes and up to barber pole speed, while telling the captain we weren't going to make our altitude restriction. When it finally became obvious, the captain told ATC that it was going to be doubtful if we made our altitude. Center replied with the classic, 'do the best you can,' to which I replied to the captain, 'that's not a change in the clearance, we still have to make it.' the captain replied to me that we were relieved of the mandatory crossing restriction, to which I replied, 'no we're not.' I don't know if the captain receives the ASRS 'callback' or not, but I think this subject needs addressing again. We were at least 3000' high at our crossing position. I hate that. Also, if a controller issues a ridiculous clearance he should be prepared to modify it. I'm sure he was well intentioned when he said, 'do your best, ' but we both know that doesn't cut it in the courtroom.

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Original NASA ASRS Text

Title: ACR WDB ALT DEVIATION UNDERSHOT CROSSING RESTRICTION BECAUSE ARTCC RADAR CTLR GAVE CLRNC TOO LATE FOR ACFT PERFORMANCE.

Narrative: CRUISING AT FL430 TO STAY ABOVE NUMEROUS TSTMS ENRTE, WE WERE APCHING PHX FROM THE E. COPLT FLYING ASKED CAPT TO OBTAIN DSCNT CLRNC. WE WERE OFF ARWYS AT THE TIME, DEVIATING WX, AND GETTING CLOSE TO PHX. WHEN CENTER FINALLY GAVE US DSCNT CLRNC THEY GAVE US ABOUT 25 MI TO GET DOWN TO FL240. NOW ONE THING THE WDB DOESN'T DO WELL IS COME DOWN IN A HURRY. KNOWING THE AMOUNT OF TIME IT TAKES THE COMPUTER TO FIGURE OUT A DSCNT PROFILE, AND THAT WE WERE WAY BEHIND ANYWAY, THE COPLT DISENGAGED THE AUTOPLT AND AUTOTHROTTLES AND BEGAN A DSCNT WITH FULL SPD BRAKES AND UP TO BARBER POLE SPD, WHILE TELLING THE CAPT WE WEREN'T GOING TO MAKE OUR ALT RESTRICTION. WHEN IT FINALLY BECAME OBVIOUS, THE CAPT TOLD ATC THAT IT WAS GOING TO BE DOUBTFUL IF WE MADE OUR ALT. CENTER REPLIED WITH THE CLASSIC, 'DO THE BEST YOU CAN,' TO WHICH I REPLIED TO THE CAPT, 'THAT'S NOT A CHANGE IN THE CLRNC, WE STILL HAVE TO MAKE IT.' THE CAPT REPLIED TO ME THAT WE WERE RELIEVED OF THE MANDATORY XING RESTRICTION, TO WHICH I REPLIED, 'NO WE'RE NOT.' I DON'T KNOW IF THE CAPT RECEIVES THE ASRS 'CALLBACK' OR NOT, BUT I THINK THIS SUBJECT NEEDS ADDRESSING AGAIN. WE WERE AT LEAST 3000' HIGH AT OUR XING POS. I HATE THAT. ALSO, IF A CTLR ISSUES A RIDICULOUS CLRNC HE SHOULD BE PREPARED TO MODIFY IT. I'M SURE HE WAS WELL INTENTIONED WHEN HE SAID, 'DO YOUR BEST, ' BUT WE BOTH KNOW THAT DOESN'T CUT IT IN THE COURTROOM.

Data retrieved from NASA's ASRS site as of August 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.