[TWEAK] B825.11 - AAM variable burnout speed calculations

[amizaur]

Hello,

I'd like to report something regarding the new "Variable AAM Burnout Velocity" option.

I was quite excited to check it , couldn't restist to make some testing. I checked maksimum performance, typical, nominal (1.5Ma) and low&slow scenarios. I find most of the results somewhat strange (debatable), but the region where the formula for variable missile burnout velocity really breaks down is at very low launching speeds.

For example when the launching platform is stationary (a hovering helo - I like to check edge cases ), then the resulting burnout velocity of AIM-9M is... 0kts. The missile hangs in the air When AIM-9M is launched at 1kts, it's burnout velocity is around 253kts. So you may want to check this .

I attached a simple scenario with a fast afterburning Su-24 as a target and a hovering AIM-9M armed AH-1Z as launching platform. (The fast target was needed to generate DLZ greater than missile minimum range).

Load the scenario and try to launch an AIM-9M from AH-1Z against Su-24. The missile after launch hangs in the air.
Then load the scenario again, change AH-1Z speed to 1kts, wait a second for it to actually start moving at 1kts and again launch AIM-9M at Su-24. The resulting missile burnout speed should be around 253kts.

There is also an AH-64E with Stingers to play with, and an Shahed as a second target (but it's to slow to generate useable DLZ form missiles).

P.S. BTW I noticed that AH-64 can't use it's 30mm gun against air targets, even as slow as Shahed. Also AH-64 probably can't use it's Stingers against "weapon" type targets (like a cruise missile), but fortunately can against Shahed drones. I may make another thread to report that.

Regards!

[Dimitris]

Good catch, thanks!

[Dimitris]

We did some significant tweaks to this for the next update. In this specific case, the burnout speed of the AIM-9M was increased to 475 knots, which is reasonable considering the stationary fire and low altitude.

[Dimitris]

@amizaur: Thanks for your further feedback and comments. The OP issue revolved around how the boost model made incorrect use of the DB-provided data (for example, and in particular, the "zero burnout speed from launch-at-hover" issue). This obviously unrealistic behavior has been fixed.

Your reply, and particularly this graphic:

...suggests that the model now works correctly, but the underlying data (provided from the DB) prevent it from more closely matching the RL curves you provided. This is a separate subject, and in order to have it discussed and investigated properly, I have moved your follow-up posts on this new dedicated thread: https://forums.matrixgames.com/viewtopic.php?t=416091

You have also made a worth-discussing wider point about other, long-ranged missiles and the different propulsion models that may be suitable for them. I have moved this to a separate thread, as again it's a different point: https://forums.matrixgames.com/viewtopic.php?t=416092

Feel free to continue the discussion on each of these threads. Thanks again!