User manual

PFPX - Professional Flight Planner X
Aerosoft GmbH 2013
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To fly to a planned destination usually requires a re-release by the airline
dispatcher.
If the short release destination airport is a point along the original route,
be-fore or after the redispatch fix, nearer to the redispatch fix than the
planned destination, then a decision to route back to the short release
destination airport or continue on to the planned destination airport
can be made be-fore reaching the redispatch fix. The decision can only
be made based on whether the fuel remaining at the redispatch fix will
ensure sufficient con-tingency fuel on board at the planned destination
airport.
Contingency fuel
With increasing flying distance, and therefore time, contingency fuel
(called international reserve fuel in the United States) requirements con-
sistently in-crease. At a redispatch fix, an agreement with dispatch that
the flight can be re-released to the planned destination airport effec-
tively resets the contin-gency fuel requirement to zero at that point.
The distance, and therefore time remaining between the redispatch fix
and the planned destination is much lower than the distance/time from
the de-parture airport to the planned destination airport.
Each calculation requires contingency fuel over its entire distance, but
each is less than the total that would be required for the entire flight to
the planned destination.
The actual flight must carry the greater of the contingency fuels for the
two scenarios. This results in a contingency fuel requirement at the re-
dispatch fix lower than at the departure airport without redispatch.
The reduction in contingency fuel between the released flight plan and
the redispatch flight plan can now be used to:
• reduce the release fuel, decreasing the take-off weight and lan-
ding weight (see the example of take-off weight decrease with
constant payload), and/or
• increase the payload (see the example of payload increase with
con-stant take-off weight).