Narrative:

I opted to add 1500 pounds of fuel for this flight. Some of the factors leading to that decision were: soft tarmac at ZZZ and high gross takeoff weight made single-engine taxi impractical. Although dispatch reported to me an average of 20 mins of taxi time for recent departures; my experience for our time-frame was closer to 45 mins. Finally; having never flown to ZZZZ; I decided to add a bit of fuel for possible inefficiencies on my part; owing to conservative (early) dscnts and early flap and landing gear extension. In fact; taxi breakaway thrust was high with 2-ENGS (at or near 70%); and would have been dangerous; if not impossible with one. Our taxi time was over 40 mins. The flight itself went as planned; at mach .80/FL370; on the filed track. Still; the en route burn was 1500 pounds over the flight plan. On the approach to ZZZZ; level 1 rain showers and thunderstorms were scattered around the airport. We were given a 5 min hold at an IAP; at 200 KTS assigned. We needed flaps 5 degrees and engine anti-ice during the entire approach. Upon arrival; our fuel was 14700 pounds. This is adequate; owing to the added fuel. In total; our fuel burn exceeded the planned burn by 2700 pounds. As usual; the automated flight plan's fuel burn starts out very accurate; and diverges in a more or less linear fashion; owing to ATC delays; WX variances and the general age and condition of the airframes and powerplants of our less than new fleet. The flight crew determined that this flight; just like every other flight would include external factors which would render the fuel burn/flight time calculations useful; but far from perfect. I added an appropriate amount of fuel for the conditions; thereby perfecting the already very good computerized flight plan calculations; as we all usually do. In this way; we (daily) keep the operation safer and provide ourselves and our passenger a better chance of completing our flts to the originally intended destination; on time and with safety. Experience and training averted a potentially compromised in-flight situation; while we were still safely on the ground; the very job description of 'PIC.' no big deal; when the system is allowed to work as it has for over 100 yrs. In general; 'events' such as this one occur daily; especially with the international operation. As are most decisions; this fuel situation was handled professionally and cordially between the dispatcher and myself; with the consultation and consent of the first officer and so. The point of this report is to illustrate a couple of things: factors which do not appear on the flight plan affect fuel planning and must be taken into account by the PIC. Secondly; the threat that decisions of the kind described herein might lead to extra-contractual and ill-conceived 'training' will not affect the ultimate decision for safety; made by the PIC; however it is a distraction and possible impediment to safety; as well as being completely counter-productive. Let the pilots and dispatchers plan and execute the flying. Let training manager and the flight training department train; rather than be an arm of enforcement. Let training manager remain safely in his office; thinking back to a time when he would have dearly loved to have a bit more fuel.

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Original NASA ASRS Text

Title: A B767 PILOT JUSTIFIES AN ADDITIONAL 1500 LBS OF FUEL ADDED ON AN INTL FLT WITH WX AND FLT DELAYS.

Narrative: I OPTED TO ADD 1500 LBS OF FUEL FOR THIS FLT. SOME OF THE FACTORS LEADING TO THAT DECISION WERE: SOFT TARMAC AT ZZZ AND HIGH GROSS TKOF WT MADE SINGLE-ENG TAXI IMPRACTICAL. ALTHOUGH DISPATCH RPTED TO ME AN AVERAGE OF 20 MINS OF TAXI TIME FOR RECENT DEPS; MY EXPERIENCE FOR OUR TIME-FRAME WAS CLOSER TO 45 MINS. FINALLY; HAVING NEVER FLOWN TO ZZZZ; I DECIDED TO ADD A BIT OF FUEL FOR POSSIBLE INEFFICIENCIES ON MY PART; OWING TO CONSERVATIVE (EARLY) DSCNTS AND EARLY FLAP AND LNDG GEAR EXTENSION. IN FACT; TAXI BREAKAWAY THRUST WAS HIGH WITH 2-ENGS (AT OR NEAR 70%); AND WOULD HAVE BEEN DANGEROUS; IF NOT IMPOSSIBLE WITH ONE. OUR TAXI TIME WAS OVER 40 MINS. THE FLT ITSELF WENT AS PLANNED; AT MACH .80/FL370; ON THE FILED TRACK. STILL; THE ENRTE BURN WAS 1500 LBS OVER THE FLT PLAN. ON THE APCH TO ZZZZ; LEVEL 1 RAIN SHOWERS AND TSTMS WERE SCATTERED AROUND THE ARPT. WE WERE GIVEN A 5 MIN HOLD AT AN IAP; AT 200 KTS ASSIGNED. WE NEEDED FLAPS 5 DEGS AND ENG ANTI-ICE DURING THE ENTIRE APCH. UPON ARR; OUR FUEL WAS 14700 LBS. THIS IS ADEQUATE; OWING TO THE ADDED FUEL. IN TOTAL; OUR FUEL BURN EXCEEDED THE PLANNED BURN BY 2700 LBS. AS USUAL; THE AUTOMATED FLT PLAN'S FUEL BURN STARTS OUT VERY ACCURATE; AND DIVERGES IN A MORE OR LESS LINEAR FASHION; OWING TO ATC DELAYS; WX VARIANCES AND THE GENERAL AGE AND CONDITION OF THE AIRFRAMES AND POWERPLANTS OF OUR LESS THAN NEW FLEET. THE FLT CREW DETERMINED THAT THIS FLT; JUST LIKE EVERY OTHER FLT WOULD INCLUDE EXTERNAL FACTORS WHICH WOULD RENDER THE FUEL BURN/FLT TIME CALCULATIONS USEFUL; BUT FAR FROM PERFECT. I ADDED AN APPROPRIATE AMOUNT OF FUEL FOR THE CONDITIONS; THEREBY PERFECTING THE ALREADY VERY GOOD COMPUTERIZED FLT PLAN CALCULATIONS; AS WE ALL USUALLY DO. IN THIS WAY; WE (DAILY) KEEP THE OP SAFER AND PROVIDE OURSELVES AND OUR PAX A BETTER CHANCE OF COMPLETING OUR FLTS TO THE ORIGINALLY INTENDED DEST; ON TIME AND WITH SAFETY. EXPERIENCE AND TRAINING AVERTED A POTENTIALLY COMPROMISED INFLT SITUATION; WHILE WE WERE STILL SAFELY ON THE GND; THE VERY JOB DESCRIPTION OF 'PIC.' NO BIG DEAL; WHEN THE SYS IS ALLOWED TO WORK AS IT HAS FOR OVER 100 YRS. IN GENERAL; 'EVENTS' SUCH AS THIS ONE OCCUR DAILY; ESPECIALLY WITH THE INTL OP. AS ARE MOST DECISIONS; THIS FUEL SITUATION WAS HANDLED PROFESSIONALLY AND CORDIALLY BTWN THE DISPATCHER AND MYSELF; WITH THE CONSULTATION AND CONSENT OF THE FO AND SO. THE POINT OF THIS REPORT IS TO ILLUSTRATE A COUPLE OF THINGS: FACTORS WHICH DO NOT APPEAR ON THE FLT PLAN AFFECT FUEL PLANNING AND MUST BE TAKEN INTO ACCOUNT BY THE PIC. SECONDLY; THE THREAT THAT DECISIONS OF THE KIND DESCRIBED HEREIN MIGHT LEAD TO EXTRA-CONTRACTUAL AND ILL-CONCEIVED 'TRAINING' WILL NOT AFFECT THE ULTIMATE DECISION FOR SAFETY; MADE BY THE PIC; HOWEVER IT IS A DISTR AND POSSIBLE IMPEDIMENT TO SAFETY; AS WELL AS BEING COMPLETELY COUNTER-PRODUCTIVE. LET THE PLTS AND DISPATCHERS PLAN AND EXECUTE THE FLYING. LET TRAINING MGR AND THE FLT TRAINING DEPT TRAIN; RATHER THAN BE AN ARM OF ENFORCEMENT. LET TRAINING MGR REMAIN SAFELY IN HIS OFFICE; THINKING BACK TO A TIME WHEN HE WOULD HAVE DEARLY LOVED TO HAVE A BIT MORE FUEL.

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