Originally Posted by
roadrabbit
Actually,there is more to it than that. If you are flying a commercial flight you will come under the FAA, CAA, or whatever legislative body controls aviation in the countries in which you fly, all in accordance with the minimum rules as laid down by ICAO. [ICAO Annex 6 part 1, para 4.3.6.3] They determine in law the minimum fuel to be loaded onto an aircraft. They typically use the parameters I stated in my opening question. What I am trying to find out is the content of those legal parameters. It appears that now the SID and runway used at departure, destination and alternate airfields can be that which would be used in line with the weather and the forecast for the expected time of departure and arrival.
What airlines actually do is work to those minimum parameters, even if they phrase them slightly differently. They may also choose to carry more fuel then that specified in the legal criteria. They cannot legally carry less.
Ok. But just as a quick example, you say 5% contingency, my company uses 2%, previous company used 10%. Current company and previous company flight planning software didn't allow for a STAR or SID so departure and arrival allowances were added. The question can't be answered without getting into specifics of who and where.