madrat wrote:sprstdlyscottsmn wrote:And from simulations I can tell you that isn't possible. Not the 50% increase from C-7 to D that is reported.

Due to drag or kinematics?

yes.

Okay, for the sake of discussion I will fire up my latest stable version of my missile guidance and performance simulator. For this discussion all shots will be head on at 36,000ft with shooter and target moving 0.9M.

I will start with the standard AIM-120C-5 Motor as I know it (135lb fuel, 265ISP) and give it an 8 second burn (gives 4,470lb thrust) and a 0 degree loft. (link to the atk site is a dead link, but with it having been referenced I will accept that it was true) I will check what launch ranges result in the missile still moving Mach 1+ at impact.

0 deg loft

a 41nm shot gives a final speed of 1.01M, peak speed of 4.85M, and a final distance of 28.4nm.

5 deg loft

a 44nm shot gives a final speed of 1.02M, peak speed of 4.87M, and a final distance of 31.5nm.

10 deg loft

a 53nm shot gives a final speed of 1.03M, peak speed of 4.85M, and a final distance of 38.2nm.

15 deg loft

a 71nm shot gives a final speed of 1.00M, peak speed of 4.84M, and a final distance of 51.0nm.

20 deg loft

a 95nm shot gives a final speed of 1.01M, peak speed of 4.81M, and a final distance of 68.7nm.

Well. I need to eat (my words/crow/humble pie).

The AIM-120D setup I was using was 150lb propellant, 3s boost (at 2.6:1 ratio) and 14 sec sustain with a 19deg loft. Using the above firing scenario gives a 124nm shot gives a final speed of 1.02M, peak speed of 4.92M, and a final distance of 92.5nm.

I was "calibrating" it with a 33,000ft shot from 1.02 to a 33,000ft 0.83M target (effectively the MINIZAP setup) which yielded a 111nm shot for a 1.0M finish (I was looking for a 1.2M finish in calibration).

Back to the drawing board. Thank you eloise for challenging my assertions and assumptions. Not only can max range drastically increase, but the range at which the missile still has high speed increases as well.