Date: 201204
Local time of day: 1801-2400
Location: SFO.Airport, CA
Flight conditions: IMC
Aircraft: B767-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Landing
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Company Policy; Weather
Primary problem: Weather

Narrative: Flight planned for good weather at arrival and arrival fuel of 11;200 pounds. Due to enroute turbulence we spent a good amount of time at lower than flight planned altitude; but had a better than planned ground speed which counterbalanced the extra fuel burn. However; within about 50 miles of destination; due to deteriorating weather we received extensive vectors during approach sequencing; mostly at 180 KTS and below 15;000 FT in icing conditions. Fuel burn rate throughout the traffic pattern was averaging 8;000 to 8;500 pounds per hour. Due to the vectoring and icing conditions we burned 4;000 pounds more than flight planned fuel and landed with about 7;000 pounds. Even though this is legal; it is not an acceptable margin for the 767.We need to recognize that the flight environment is unpredictable and we need to stop flight planning for fuel margins that are at the limits of legality because in many cases they are below the limits of prudence; and do not contain acceptable margins of safety. Weather and traffic can change drastically without notice. Pilots should not be placed in the position of having to ask for extra fuel on every flight in order to have an acceptable reserve because this creates an implicit pressure to lower the margins of safety in the interest of cost savings. In the long run this will not save any money because it will lead to more fuel stops; diversions; and ultimately may lead to an accident. Our flight planning system needs to be changed in order to reflect this.


Second narrative: Flight planned for good weather at SFO with arrival fuel of 11;200 pounds. Due to enroute turbulence we spent time lower than our planned altitude. We also climbed and decended multiple times in search of good air. When in ZOA airspace we where continually vectored and slowed further increasing fuel burn. Upon entering NorCal airspace we encountered extensive vectoring and slowed to 180 KTS with flaps 5 for extended period. During this time period engine and wing ice systems were on. All these factors caused us to burn an additional 4;000 pounds of fuel. The factors we encountered were not flight planned for. We landed with approximately 7;000 pounds of fuel. This was not an acceptable margin for a 767-200.We need to recognize that there are conditions during the actual flight that can not be accounted for in the planning stage by either Dispatch or flight crew. Fuel loads should not be planned to legal minimums and first officers should be integrated to a greater extent in the process.


Synopsis: B767-200 flight crew reports burning significantly more fuel than planned during arrival to SFO due to weather.