Additional features
Over and above the various cost-reduction measures mentioned above, flight planning
systems may offer extra features to help attract and retain customers:
•
Other routes
While a flight plan is produced for a specific route, flight dispatchers may wish to consider
alternative routes. A flight planning system may produce summaries for, say, the next 4 best
routes, showing zero fuel weight and total fuel for each possibility.
•
Reclear selection
There may be several possible reclear fixes and initial destinations, and which one is best
depends on the weather and the zero fuel weight. A flight planning system can analyse each
possibility and select whichever is best for this particular flight.
•
What-if summaries
On congested routes, air traffic control may require that an aircraft fly lower or higher than
optimum. The total weight of passengers and cargo might not be known at the time the flight
plan is prepared. To allow for these situations a flight planning system may produce
summaries showing how much fuel would be needed if the aircraft is a little lighter or heavier,
or if it is flying higher or lower than planned. These summaries allow flight dispatchers and
pilots to check if there is enough reserve fuel to cope with a different scenario.
•
Fuel tank distribution
Most commercial aircraft have more than one fuel tank, and an aircraft manufacturer may
provide rules as to how much fuel to load into each tank so as to avoid affecting the aircraft
centre of gravity. The rules depend on how much fuel is to be loaded, and there may be
different sets of rules for different total amounts of fuel. A flight planning system may follow
these rules and produce a report showing how much fuel is to be loaded into each tank.
•
Tankering fuel
When fuel prices differ between airports, it might be worth putting in more fuel where it is
cheap, even taking into account the cost of extra trip fuel needed to carry the extra weight. A
flight planning system can work out how much extra fuel can profitably be carried. Note that
discontinuities due to changes in flight levels can mean that a difference of as little as 100 kg
(one passenger with luggage) in zero fuel weight or tankering fuel can make the difference
between profit and loss.
A - Z of Flight
July 2017
www.alliance-airways.net
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