Fuel

Fuel units

In ATC-NG fuel consumption is constant per unit of space travelled. This means that a plane will consume the same amount of fuel regardless of its travelling speed.

To make possible to compare scores obtained on different maps/scenarios, fuel units are calculated based on the size of the aerospace, so that the maximum fuel capacity for any aeroplane in ATC-NG, is always 1000, which corresponds to the amount of fuel needed to travel [1] four times along the diagonal of the aerospace monitored on the radar screen. However each plane enters the game loaded with just enough fuel to fly four times between its entry and destination points [1].

The expedite flag

All commands that imply a change in either altitude, heading or speed can be issued in combination with the flag EXPEDITE: if a command is issued with such flag, the plane will consume twice as much during the time the manoeuvre will take to complete (on the other hand, the manoeuvre will be performed quicker).

Fuel emergency

A plane declares fuel emergency when its fuel will be less than twice the amount needed to fly the [1] distance between the current aeroplane position and its destination.

Running out of fuel

A plane that runs out of fuel doesn’t immediately crash. Its flying parameters get instead modified to simulate an unpowered glide:

• Given min the nominal minimum flying speed for the aeroplane, the speed range will be limited to min <= speed <= 2*min
• Given max the nominal maximum descent ratio for the aeroplane, the climb ratio will be limited to max/2 <= descent ratio <= max.

Example: an aeroplane whose normal flight speed range is between 200 and 900 kph, will be limited to 200 to 400 kph. Similarly, if its nominal climbing rate limits are -30 and +15 m/s, its new ones will be -30 and -15.

[1]	(1, 2, 3) These distances are calculated “as the crow flies”. The actual distance will be longer unless the aeroplane is already flying straight towards its destination.