WesWorld

Hi!

I have one simple question:

When a data sheet of a planes says it has a range of 500km - what does that mean?

a) 500km is the maximum distance between two points before it needs to land

or

b) 500km is the maximum distance from point A to point B from which the plane can safely return to A

Of course parameters like wind, rotation of the earth etc. could also factor in but should be ignored here.

My answer would be... A.

Radius is B.

If in a serious book then A if on the internet it can be A,B & C (being combat radius)

It depends a lot, but it would most commonly be range. Still, its not the absolute range. Probably -10% or 20%.

For combat radius, the typical profile for fighters is 10min combat at full power with around 15min for take off and climb. The fuel remaining takes into account the radius of action. From looking at a few figures you need around 120% fuel to take into account the things above.

As a secondary consideration, theres usually a limit on how much internal volume is free for fuel tanks. This leads to drop tanks usually. Still, theres usually a fair amount of room internally. A long range Spitfire when having all the internal tankage fitted to the various versions comes as having a radius of around 1000m.