Narrative:

Initial route filed to las was for best wind; 'direct requests discouraged.' this route was a southwesterly track from sax to bwg; then along a southerly route through arg to tul to las; to avoid jet stream winds. Departing clearance delivery issued a full-route clearance which tracked across the northern portion of the united states to approximately rod; then southwest to vhp; stl; bum and west to las. I knew we had significant winds aloft from WX packet review; but had not mentally plotted the original flight plan or the revision. I was overseeing a new-hire's efforts (first trip off IOE; inexperienced with airline operations); and making sure he read back and loaded new clearance into FMC. I phoned dispatch to advise of reroute; to have them produce new burn/time numbers; asked them to ACARS results. While waiting for their response; departing city's clearance advised of second reroute. New route was across top of united states to gij; then southwesterly to las; it was the XXX/las 01 route (again; I didn't map this out and compare against original route; or against the winds aloft diagram). Dispatch sent ACARS note to advise this second route was the '01' route; and included new burn/time numbers. We were past push time; and had to deice prior to push. I looked at the new burn and time numbers. Original en route burn was 27.6; arrival fuel 6.7 (1 hour contingency; no alternate required). New burn was 28.7 (+1.1; +15 mins); new arrival fuel 5.6. I decided this was acceptable. We pushed and departed. Once en route; I began to check the original route against the new route; to check fuel burn at en route points. It was then that I discovered the new route was significantly further north than the original; and that we had no accurate means of tracking fuel burn; given the significantly different wind conditions aloft for the 2 rtes. I had not requested a new release be printed prior to push. Now I had to estimate winds at en route points based on the 35000 ft wind depiction provided with the WX packet; plug them into the FMC; and then manually calculate fuel estimates for each point. I requested dispatch calculate our new fuel/time data as well; using their forecast winds and current fuel state; with the flight planning computer. They sent via ACARS a flight log similar to page 2 of release. Their plan showed us arriving sino with the same fuel as the originally issued flight dispatch release (the southerly route); but now arriving with 5.3. My own estimates initially showed arrival with 5.9. However; by lnc; we were about 1.4 below my estimate. I advised dispatch; included winds; requested updated arrival fuel estimate; and consider fuel stop den. Dispatch provided new arrival fuel of 5.0; advised winds would drop off after den (they remained above 100 KTS headwind until well into the descent west of dvc); advised against den divert. We pressed on; but further updates tracked with earlier observation: running 1.4 behind my original burn estimates; now arriving las 4.5. Told first officer that I would fly the arrival and landing. Checked las ATIS again. Now strong winds from north; arrs on runways 25L; 01L/right. Checking in with las approach; advised to expect vectors runway 1L. I requested runway 25L; told not available unless fuel a problem. I declared 'minimum fuel;' was vectored to final runway 25L. Touched down with 4.3. Classic example of too many things competing for my attention close to departure; losing track of priorities (although I thought that having dispatch crunch the new burn/time numbers and wiring me with results was a good use of resources). As a minimum; I should have had another dispatch release generated to better track the new route on this flight. I should have sketched the original and revised route tracks; compared against the winds aloft depiction; and then spoken in more detail with dispatch. I could easily have loaded additional fuel; to at least retain the full 1:00 contingency pad; although arrival fuel would still have been significantly below original plan. In short; the original burn calculation provided by dispatch was inaccurate. By their original estimate; we should have arrived with 5.6; vice the 4.3 actual. The winds aloft appeared to be stronger than forecasted; as well. If the wind forecast has a significant error margin; then more contingency fuel should be loaded for these long-haul; winter time segments. Also; the far reserve number for this flight seems unusually low: 2.8 for 00:45. I was very uncomfortable with our fuel situation for the last 2 hours of the trip; and regret not having diverted to den for fuel. Possible action by dispatch to review such flts against accuracy of wind and fuel burn data would be warranted.

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Original NASA ASRS Text

Title: A B737-700 WAS REROUTED TWICE BEFORE TKOF. THE FINAL RTE WAS INTO THE JET STREAM AND WITH THE FUEL BURN INCREASE THE FLT LANDED WITH 4300 LBS OF FUEL.

Narrative: INITIAL RTE FILED TO LAS WAS FOR BEST WIND; 'DIRECT REQUESTS DISCOURAGED.' THIS RTE WAS A SOUTHWESTERLY TRACK FROM SAX TO BWG; THEN ALONG A SOUTHERLY RTE THROUGH ARG TO TUL TO LAS; TO AVOID JET STREAM WINDS. DEPARTING CLRNC DELIVERY ISSUED A FULL-RTE CLRNC WHICH TRACKED ACROSS THE NORTHERN PORTION OF THE UNITED STATES TO APPROX ROD; THEN SW TO VHP; STL; BUM AND W TO LAS. I KNEW WE HAD SIGNIFICANT WINDS ALOFT FROM WX PACKET REVIEW; BUT HAD NOT MENTALLY PLOTTED THE ORIGINAL FLT PLAN OR THE REVISION. I WAS OVERSEEING A NEW-HIRE'S EFFORTS (FIRST TRIP OFF IOE; INEXPERIENCED WITH AIRLINE OPS); AND MAKING SURE HE READ BACK AND LOADED NEW CLRNC INTO FMC. I PHONED DISPATCH TO ADVISE OF REROUTE; TO HAVE THEM PRODUCE NEW BURN/TIME NUMBERS; ASKED THEM TO ACARS RESULTS. WHILE WAITING FOR THEIR RESPONSE; DEPARTING CITY'S CLRNC ADVISED OF SECOND REROUTE. NEW RTE WAS ACROSS TOP OF UNITED STATES TO GIJ; THEN SOUTHWESTERLY TO LAS; IT WAS THE XXX/LAS 01 RTE (AGAIN; I DIDN'T MAP THIS OUT AND COMPARE AGAINST ORIGINAL RTE; OR AGAINST THE WINDS ALOFT DIAGRAM). DISPATCH SENT ACARS NOTE TO ADVISE THIS SECOND RTE WAS THE '01' RTE; AND INCLUDED NEW BURN/TIME NUMBERS. WE WERE PAST PUSH TIME; AND HAD TO DEICE PRIOR TO PUSH. I LOOKED AT THE NEW BURN AND TIME NUMBERS. ORIGINAL ENRTE BURN WAS 27.6; ARR FUEL 6.7 (1 HR CONTINGENCY; NO ALTERNATE REQUIRED). NEW BURN WAS 28.7 (+1.1; +15 MINS); NEW ARR FUEL 5.6. I DECIDED THIS WAS ACCEPTABLE. WE PUSHED AND DEPARTED. ONCE ENRTE; I BEGAN TO CHK THE ORIGINAL RTE AGAINST THE NEW RTE; TO CHK FUEL BURN AT ENRTE POINTS. IT WAS THEN THAT I DISCOVERED THE NEW RTE WAS SIGNIFICANTLY FURTHER N THAN THE ORIGINAL; AND THAT WE HAD NO ACCURATE MEANS OF TRACKING FUEL BURN; GIVEN THE SIGNIFICANTLY DIFFERENT WIND CONDITIONS ALOFT FOR THE 2 RTES. I HAD NOT REQUESTED A NEW RELEASE BE PRINTED PRIOR TO PUSH. NOW I HAD TO ESTIMATE WINDS AT ENRTE POINTS BASED ON THE 35000 FT WIND DEPICTION PROVIDED WITH THE WX PACKET; PLUG THEM INTO THE FMC; AND THEN MANUALLY CALCULATE FUEL ESTIMATES FOR EACH POINT. I REQUESTED DISPATCH CALCULATE OUR NEW FUEL/TIME DATA AS WELL; USING THEIR FORECAST WINDS AND CURRENT FUEL STATE; WITH THE FLT PLANNING COMPUTER. THEY SENT VIA ACARS A FLT LOG SIMILAR TO PAGE 2 OF RELEASE. THEIR PLAN SHOWED US ARRIVING SINO WITH THE SAME FUEL AS THE ORIGINALLY ISSUED FLT DISPATCH RELEASE (THE SOUTHERLY RTE); BUT NOW ARRIVING WITH 5.3. MY OWN ESTIMATES INITIALLY SHOWED ARR WITH 5.9. HOWEVER; BY LNC; WE WERE ABOUT 1.4 BELOW MY ESTIMATE. I ADVISED DISPATCH; INCLUDED WINDS; REQUESTED UPDATED ARR FUEL ESTIMATE; AND CONSIDER FUEL STOP DEN. DISPATCH PROVIDED NEW ARR FUEL OF 5.0; ADVISED WINDS WOULD DROP OFF AFTER DEN (THEY REMAINED ABOVE 100 KTS HEADWIND UNTIL WELL INTO THE DSCNT W OF DVC); ADVISED AGAINST DEN DIVERT. WE PRESSED ON; BUT FURTHER UPDATES TRACKED WITH EARLIER OBSERVATION: RUNNING 1.4 BEHIND MY ORIGINAL BURN ESTIMATES; NOW ARRIVING LAS 4.5. TOLD FO THAT I WOULD FLY THE ARR AND LNDG. CHKED LAS ATIS AGAIN. NOW STRONG WINDS FROM N; ARRS ON RWYS 25L; 01L/R. CHKING IN WITH LAS APCH; ADVISED TO EXPECT VECTORS RWY 1L. I REQUESTED RWY 25L; TOLD NOT AVAILABLE UNLESS FUEL A PROB. I DECLARED 'MINIMUM FUEL;' WAS VECTORED TO FINAL RWY 25L. TOUCHED DOWN WITH 4.3. CLASSIC EXAMPLE OF TOO MANY THINGS COMPETING FOR MY ATTN CLOSE TO DEP; LOSING TRACK OF PRIORITIES (ALTHOUGH I THOUGHT THAT HAVING DISPATCH CRUNCH THE NEW BURN/TIME NUMBERS AND WIRING ME WITH RESULTS WAS A GOOD USE OF RESOURCES). AS A MINIMUM; I SHOULD HAVE HAD ANOTHER DISPATCH RELEASE GENERATED TO BETTER TRACK THE NEW RTE ON THIS FLT. I SHOULD HAVE SKETCHED THE ORIGINAL AND REVISED RTE TRACKS; COMPARED AGAINST THE WINDS ALOFT DEPICTION; AND THEN SPOKEN IN MORE DETAIL WITH DISPATCH. I COULD EASILY HAVE LOADED ADDITIONAL FUEL; TO AT LEAST RETAIN THE FULL 1:00 CONTINGENCY PAD; ALTHOUGH ARR FUEL WOULD STILL HAVE BEEN SIGNIFICANTLY BELOW ORIGINAL PLAN. IN SHORT; THE ORIGINAL BURN CALCULATION PROVIDED BY DISPATCH WAS INACCURATE. BY THEIR ORIGINAL ESTIMATE; WE SHOULD HAVE ARRIVED WITH 5.6; VICE THE 4.3 ACTUAL. THE WINDS ALOFT APPEARED TO BE STRONGER THAN FORECASTED; AS WELL. IF THE WIND FORECAST HAS A SIGNIFICANT ERROR MARGIN; THEN MORE CONTINGENCY FUEL SHOULD BE LOADED FOR THESE LONG-HAUL; WINTER TIME SEGMENTS. ALSO; THE FAR RESERVE NUMBER FOR THIS FLT SEEMS UNUSUALLY LOW: 2.8 FOR 00:45. I WAS VERY UNCOMFORTABLE WITH OUR FUEL SITUATION FOR THE LAST 2 HRS OF THE TRIP; AND REGRET NOT HAVING DIVERTED TO DEN FOR FUEL. POSSIBLE ACTION BY DISPATCH TO REVIEW SUCH FLTS AGAINST ACCURACY OF WIND AND FUEL BURN DATA WOULD BE WARRANTED.

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.