Missiles and Fighter Kinematics

[Tempest II]

I have been thinking of missile ranges and speeds and how these factor into a fight and realising how speed/energy means survival. I have tried some rough calculations using a PL-9 as an example. I am not claiming this to be correct but this is my logic and seeking discussion.

The low energy target can be engaged more than 4km further than the high energy target. The high energy guy has a better chance of escaping especially if he climbs, making the missile work against gravity and hence loose energy faster.

I did a similar rough calculation and with BVR missiles and realised that a Mach 4, 100km range MRAAM, launched 60km to a fleeing fighter will very unlikely catch and kill it. Depending on the energy state of the target, it has time to make a U-turn and escape.

 

[Anas Ali]

very very interesting thread and i hope that everyone shares his point of view

 

[Anas Ali]

this is the amraam launch envelope it said that the lower the target the shorter the range of the missile so this needs some explaining too

 

[Tempest II]

this is the amraam launch envelope it said that the lower the target the shorter the range of the missile so this needs some explaining too

I think it is more of "the lower the launch aircraft, the shorter the range" ... ... Also is the launch aircraft is at 10,000ft and the target is at 10,000 ft, the range would be greater than the launch plane at 10k ft and the target at 5k ft. By the same logic, the range would be shorter if the launch plane is at 10k ft and the target is at 15k ft.

 

[Tempest II]

Further to illustrate the effect of launch altitude and speed, consider the SD-10 in its AAM and SAM. The SAM has a lot less range while I suspect it will have a more powerful motor. The same is true for the AIM-120 in its air-launched and SAM versions. You can also check the data for some cruise missiles that come in a surface-launched and air-launched version.
The reason for the longer range for air-launched is that even before the missiles fires its motor, it already has kinetic and potential energy from the plane. You could theoretically launch it and hit an non-evading target a few kilometers away without even firing it motors.
The energy imparted by the plane to the missile is one factor the likes of Typhoon and F-22 are designed to work at high altitude and high speed. This high energy state improves the range of their weapons and reduces the range of yours.

 

[Anas Ali]

thanks . its true the range of the amraam is much bigger than the slamraam for this reason you talked about
but there is some info that indicates that even if the launch platform is at the same altitude the range will be effected by that altitude for example (AIM-7C)
at 16 km alt with head on target range will be 4.5 - 12 km / tail chase range 3-8 km
at 10 km alt with head on target range will be 3 - 11 km / tail chase range 1.6-6 km
sea level alt with head on target range will be 3 - 6.5 km / tail chase range 0.6-1.9 km

here is the source it also had some good and reasonable expected ranges of missiles
Air-to-air missile non-comparison table