|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||airport : zzz.airport|
|Controlling Facilities||artcc : zzz.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||Commercial Fixed Wing|
|Operating Under FAR Part||Part 121|
|Flight Phase||cruise : level|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Independent Detector||other flight crewa|
|Resolutory Action||none taken : unable|
ATC Human Performance
Minimum fuel en route. Factors included being held down for a long length of time below filed cruising altitude and multiple ATC instructions to slow down then speed up over 20-30 KT ranges. WX/turbulence was a factor in the speed changes. Constant light; occasional moderate chop and turbulence was reported all across the region at most altitudes between FL200 and FL360. The third time we were told to speed up after a speed reduction I notified center we were unable due to being on the edge of a minimum fuel state. After a moment; the controller came back and notified me they would carry our flight as being 'minimum fuel.' a subsequent controller asked why we were minimum fuel and I explained about held down and speed changes. Aircraft are dispatched with a conservative fuel load and a small allowance for contingencies. En route factors exceeded the small allowance. We need some form of system to notify dispatchers of expected additional en route delays. On any other day our fuel would probably have been sufficient despite being held down; but the multiple speed changes; especially speeding back up; really hurt our fuel performance. If dispatchers were aware of additional delay factors on a certain segment of routing; then additional fuel could have been added. Airlines are trying to conserve fuel through better planning; but they need to have a realistic idea of any additional factors to consider. Simply adding 500-1000 pounds because ATC 'might' induce delays isn't the most effective way to plan.
Original NASA ASRS Text
Title: AN ACR CAPTAIN REPORTED FINDING HIMSELF IN A MIN FUEL STATE FOLLOWING MULTIPLE ATC SPEED AND ALTITUDE CHANGES.
Narrative: MINIMUM FUEL ENRTE. FACTORS INCLUDED BEING HELD DOWN FOR A LONG LENGTH OF TIME BELOW FILED CRUISING ALT AND MULTIPLE ATC INSTRUCTIONS TO SLOW DOWN THEN SPD UP OVER 20-30 KT RANGES. WX/TURB WAS A FACTOR IN THE SPD CHANGES. CONSTANT LIGHT; OCCASIONAL MODERATE CHOP AND TURB WAS RPTED ALL ACROSS THE REGION AT MOST ALTS BTWN FL200 AND FL360. THE THIRD TIME WE WERE TOLD TO SPD UP AFTER A SPD REDUCTION I NOTIFIED CTR WE WERE UNABLE DUE TO BEING ON THE EDGE OF A MINIMUM FUEL STATE. AFTER A MOMENT; THE CTLR CAME BACK AND NOTIFIED ME THEY WOULD CARRY OUR FLT AS BEING 'MINIMUM FUEL.' A SUBSEQUENT CTLR ASKED WHY WE WERE MINIMUM FUEL AND I EXPLAINED ABOUT HELD DOWN AND SPD CHANGES. ACFT ARE DISPATCHED WITH A CONSERVATIVE FUEL LOAD AND A SMALL ALLOWANCE FOR CONTINGENCIES. ENRTE FACTORS EXCEEDED THE SMALL ALLOWANCE. WE NEED SOME FORM OF SYS TO NOTIFY DISPATCHERS OF EXPECTED ADDITIONAL ENRTE DELAYS. ON ANY OTHER DAY OUR FUEL WOULD PROBABLY HAVE BEEN SUFFICIENT DESPITE BEING HELD DOWN; BUT THE MULTIPLE SPD CHANGES; ESPECIALLY SPEEDING BACK UP; REALLY HURT OUR FUEL PERFORMANCE. IF DISPATCHERS WERE AWARE OF ADDITIONAL DELAY FACTORS ON A CERTAIN SEGMENT OF ROUTING; THEN ADDITIONAL FUEL COULD HAVE BEEN ADDED. AIRLINES ARE TRYING TO CONSERVE FUEL THROUGH BETTER PLANNING; BUT THEY NEED TO HAVE A REALISTIC IDEA OF ANY ADDITIONAL FACTORS TO CONSIDER. SIMPLY ADDING 500-1000 LBS BECAUSE ATC 'MIGHT' INDUCE DELAYS ISN'T THE MOST EFFECTIVE WAY TO PLAN.
Data retrieved from NASA's ASRS site as of January 2009 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.