Most (all) of DCS missiles are slow than defined in its script

[GumidekCZ]

I would like to report a BUG, which is connected almost to all missiles in DCS.

There is defined max speed for every missile in DCS (you can also read them in DCS Encyclopedia) which are for ideal perfect conditions, where missile fly without any none of un-neccesary maneuver and keep accelerating to less dense air. If missile stais in level flight at low alts, it will never reach its max speed.

in this example, missile has its peak around speed in TAS: 4890 km/h which gives us TAS 1358 m/s at altitude of 5247 m.

Climb angle of 19° is taken in account in TAS, its not speed vector paralel to Earth surface.

When we use NASA calculator in metric units:

https://www.grc.nasa.gov/WWW/K-12/rocket/machu.html

Result for that alt is than Mach 4.249, which is almost the same what Tacview says (Mach 4,24).

As we now, the missile have its max speed "Mach_max = 5," defined in missile script. So there si Mach 0.75 difference (15% less), and that is a lot. I know that some of you starts to argue with me about actual air pressure and temperature... but this will not bring us back that huge amount of extra speed, the missile should have.

Some of the missiles have more close speed to its defined max velocity, some of them are even worse than above mentioned 15%.

I can follow on with rest of DCS missiles, but it would take very long time to do so. So only one more example without track:

SA-6 3M9M missile measured in DCS with max speed Mach 1.9-2.0, in script it defined as Mach 2.2 - which it self is slow when compared to public data of M2.6~2.8 or 900m/s. That not good, really.

AIM-120C just quick check with M3.3 measured from M0.98 launched flyght - compare with max speed of Mach 4.0

Do we have is grey slowdown coeficient or am I missing something?

_DCS_SLOW_MISSILES.trk

Edited October 6, 2021 by GumidekCZ

[Raven (Elysian Angel)]

On 10/7/2021 at 12:46 AM, GumidekCZ said:

AIM-120C just quick check with M3.3 measured from M0.98 launched flyght - compare with max speed of Mach 4.0

Do we have is grey slowdown coeficient or am I missing something?

Try launching at M1.6+ or faster, at FL400+ and check again? As you stated above, they are *maximum* speeds attainable only under perfect conditions: high speed and high altitude.

[GumidekCZ]

38 minutes ago, Raven (Elysian Angel) said:

Try launching at M1.6+ or faster, at FL400+ and check again? As you stated above, they are *maximum* speeds attainable only under perfect conditions: high speed and high altitude.

Can be for A-A missiles, but what about SAMs? I can't grab SA-6 launcher or missile alone to 40k alt.

[GGTharos]

SAMs use a very old FM.  There's nothing for you to report, ED knows about this; even the AAMs aren't transitioning to the new FMs at any appreciable speed, SAMs will be last.

[GumidekCZ]

4 hours ago, GGTharos said:

SAMs use a very old FM.  There's nothing for you to report, ED knows about this; even the AAMs aren't transitioning to the new FMs at any appreciable speed, SAMs will be last.

Very old model indeed, but the max speed can be tuned by single script value "v_mid = (speed m/s)". I was able to set correct Mach # for example for SA-6 missile by adjusting this number in matter of minutes. For single skilled dev its a work for signle day to fix all SAMs and one extra for testing. After that fixed, we can wait for brand new FM.

Edited October 14, 2021 by GumidekCZ

[GGTharos]

Yes it's a single day for them to fix, maybe ... but that's a single day where they're scheduled to be working on something else.   Everyone believes their issue is easy to fix, and that may well be true.   It's just not a priority as you can see