Narrative:

Cruising at FL330, we requested a climb to FL370 for better fuel efficiency and tailwind component. Controller asked if we could be at FL370 in 2 mins and we said 'yes.' we started our climb with 2500+ FPM through at least FL355, and then climb performance started to taper off. We continued our climb with full power and best rate of climb airspeed, but did not reach our required altitude within the 2 min time period. We had opposite direction traffic, and to the best I can recall, we had over 1200+ ft vertical separation when other aircraft was 10 mi horizontal with 'traffic in sight.' in retrospect, we should not have accepted a clearance to climb 4000 ft in 2 mins at that altitude. It was a bit aggressive for the ATC controller to offer, and aggressive for us as well to accept it. Although the B757 has excellent performance, we could not guarantee sufficient climb performance to comply with ATC clearance. In the future, I will not accept such a clearance, and will be more assertive in speaking up when unable to comply, or at the first sign of doubt that a restr will not be met. Supplemental information from acn 472769: by recognizing that the 'level by' clearance would require a relatively high performance climb, and that the opposite direction traffic at the intermediate cruising altitude held a fairly high probability of potential conflict, the controller could have issued an 'off course' vector for the climb, thus obtaining the required horizontal separation for our climb, or he could simply have waited 5 or so mins to issue the straight ahead climb after the opposite direction traffic had passed astern. I should have taken more time to evaluate the performance capability of the aircraft before accepting a clearance that, in retrospect, was marginal. WX and turbulence were not factors in my request to climb, only fuel efficiency and schedule compliance. I believe that the decision making processes here were subtly influenced by my desire to save fuel in light of the recent steep increases in fuel prices and their impact on the financial health of my company. I also think the general desire by pilots and controllers to 'make things work' or the 'can do' attitude may have contributed as well. None of this relieves pilots and controllers from critical analysis of the human and mechanical performance which is being required in each ATC situation, and taking the more prudent course of action whenever the outcome is in doubt. Complying with even arbitrary rules of aircraft separation, ensures the integrity and safety of the entire ATC system.

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Original NASA ASRS Text

Title: B757 CREW ACCEPTS A TIME RESTR FOR CLB TO FL370 AND IS UNABLE TO COMPLY. ARTCC VECTORS 2 ACFT TO PROVIDE SEPARATION.

Narrative: CRUISING AT FL330, WE REQUESTED A CLB TO FL370 FOR BETTER FUEL EFFICIENCY AND TAILWIND COMPONENT. CTLR ASKED IF WE COULD BE AT FL370 IN 2 MINS AND WE SAID 'YES.' WE STARTED OUR CLB WITH 2500+ FPM THROUGH AT LEAST FL355, AND THEN CLB PERFORMANCE STARTED TO TAPER OFF. WE CONTINUED OUR CLB WITH FULL PWR AND BEST RATE OF CLB AIRSPD, BUT DID NOT REACH OUR REQUIRED ALT WITHIN THE 2 MIN TIME PERIOD. WE HAD OPPOSITE DIRECTION TFC, AND TO THE BEST I CAN RECALL, WE HAD OVER 1200+ FT VERT SEPARATION WHEN OTHER ACFT WAS 10 MI HORIZ WITH 'TFC IN SIGHT.' IN RETROSPECT, WE SHOULD NOT HAVE ACCEPTED A CLRNC TO CLB 4000 FT IN 2 MINS AT THAT ALT. IT WAS A BIT AGGRESSIVE FOR THE ATC CTLR TO OFFER, AND AGGRESSIVE FOR US AS WELL TO ACCEPT IT. ALTHOUGH THE B757 HAS EXCELLENT PERFORMANCE, WE COULD NOT GUARANTEE SUFFICIENT CLB PERFORMANCE TO COMPLY WITH ATC CLRNC. IN THE FUTURE, I WILL NOT ACCEPT SUCH A CLRNC, AND WILL BE MORE ASSERTIVE IN SPEAKING UP WHEN UNABLE TO COMPLY, OR AT THE FIRST SIGN OF DOUBT THAT A RESTR WILL NOT BE MET. SUPPLEMENTAL INFO FROM ACN 472769: BY RECOGNIZING THAT THE 'LEVEL BY' CLRNC WOULD REQUIRE A RELATIVELY HIGH PERFORMANCE CLB, AND THAT THE OPPOSITE DIRECTION TFC AT THE INTERMEDIATE CRUISING ALT HELD A FAIRLY HIGH PROBABILITY OF POTENTIAL CONFLICT, THE CTLR COULD HAVE ISSUED AN 'OFF COURSE' VECTOR FOR THE CLB, THUS OBTAINING THE REQUIRED HORIZ SEPARATION FOR OUR CLB, OR HE COULD SIMPLY HAVE WAITED 5 OR SO MINS TO ISSUE THE STRAIGHT AHEAD CLB AFTER THE OPPOSITE DIRECTION TFC HAD PASSED ASTERN. I SHOULD HAVE TAKEN MORE TIME TO EVALUATE THE PERFORMANCE CAPABILITY OF THE ACFT BEFORE ACCEPTING A CLRNC THAT, IN RETROSPECT, WAS MARGINAL. WX AND TURB WERE NOT FACTORS IN MY REQUEST TO CLB, ONLY FUEL EFFICIENCY AND SCHEDULE COMPLIANCE. I BELIEVE THAT THE DECISION MAKING PROCESSES HERE WERE SUBTLY INFLUENCED BY MY DESIRE TO SAVE FUEL IN LIGHT OF THE RECENT STEEP INCREASES IN FUEL PRICES AND THEIR IMPACT ON THE FINANCIAL HEALTH OF MY COMPANY. I ALSO THINK THE GENERAL DESIRE BY PLTS AND CTLRS TO 'MAKE THINGS WORK' OR THE 'CAN DO' ATTITUDE MAY HAVE CONTRIBUTED AS WELL. NONE OF THIS RELIEVES PLTS AND CTLRS FROM CRITICAL ANALYSIS OF THE HUMAN AND MECHANICAL PERFORMANCE WHICH IS BEING REQUIRED IN EACH ATC SIT, AND TAKING THE MORE PRUDENT COURSE OF ACTION WHENEVER THE OUTCOME IS IN DOUBT. COMPLYING WITH EVEN ARBITRARY RULES OF ACFT SEPARATION, ENSURES THE INTEGRITY AND SAFETY OF THE ENTIRE ATC SYS.

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.