Flight Planning - Additional Features

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.

• Inflight diversion

While en route, an aircraft may be diverted to some airport other than the planned alternate. A flight planning system can produce a new flight plan for the new route from the diversion point and transmit it to the aircraft, including a check that there will be enough fuel for the revised flight.

• Inflight refuelling

Military aircraft may refuel in mid-air. Such refuelling is a gradual process rather than instantaneous. Some flight planning systems can allow for the change in fuel and show the effect on each aircraft involved.