AIM-7M battery power / range?

What is the AIM-7M battery lifetime?

Was watching a replay and noticed the F-15C launch AIM-7M at 15 000 metres (49000 ft) with a lofting profile against a 2 square meter target (AIM-7F/M launch range to MiG-21Bis was 63 kilometres / 34 nm, that is over 12 nmi longer than specification says at best case scenario) that gets interrupted early in the guidance flight and lead to missile have over 175 kilometre flight (94,4 nmi) that lasted 8 min 15 seconds (aerodynamic range said to be 98 km for 40 k/ft launch in F model)

After 4 minutes from the launch the missile speed was Mach 0.9 and it has traveled little over 120 km. After 8 minutes of launch it just passes 170 km range with Mach 0.48, and still performed corrections in flight path to keep perfect glide slope, denying "nose-down" dive.

Raero is 53nm at alt, you said the shot was 34nm so kinematically this is well within range. The issue is the seeker which should cap it to around 25nm in this secnario (DCS MiG-21 has an RCS of 3m^2), but dcs doesnt model SARH seeker limits afaik. As for the battery life, thats really odd, in the files its supposed to be 75 sec.

The seeker range limit is part of the new model as far as I can tell whether or not it currently works is well unknown. But keep in mind for the seeker range is for a 2m^2 target from a CW transmiter from an F4 (F15?) but the F and up can home in on a PD signal which will substantially increase the seeker range. The missile battery was set too 75 sec as well iirc.

Raero is 53nm at alt, you said the shot was 34nm so kinematically this is well within range.

It is still wonderful seeker as you can get a lock further distances than a larger fighter radars with more power and/or more effective processing.

The issue is the seeker which should cap it to around 25nm in this secnario (DCS MiG-21 has an RCS of 3m^2), but dcs doesnt model SARH seeker limits afaik.

What is a big downside if seeker features doesn't seem to be modeled.

Going from a F-15C to F-4E changes the launch range to 28 km (15 nmi) why it can't be used as launching platform. It turns AIM-7F/M to a AIM-7E by the specs.

As for the battery life, thats really odd, in the files its supposed to be 75 sec.

I recalled it was around 90-120 seconds for AIM-7M, but at 75 seconds it is still magical missile.

Edit: At 75 seconds the missile has traveled only about a 60 km, that is 32 nmi.

It is 75 seconds by documentation and it has to do with available hydraulic fluid in this particular case - and that is a maximum based on specific conditions that the missile sort of takes care of on its own (dogfight vs. long range mode).

After this time, the missile should no longer be able to move the fins even if it has electrical power because the hydraulic is open-loop, ie the fluid is thrown over-board. The power available is set to 75 seconds in-game, so you may well be looking at a bug here.

As for the DSR, again according to documentation, it goes from 22nm to 38nm (or 32, I'm going by memory so the exact number is fuzzy) vs that 2m^2 target when using PD illumination.

After this time, the missile should no longer be able to move the fins even if it has electrical power because the hydraulic is open-loop, ie the fluid is thrown over-board. The power available is set to 75 seconds in-game, so you may well be looking at a bug here.

Is it possible that after the hydraulics are gone, that the control surfaces are "stuck" to optimal aerodynamic position (aerodynamic center should be slightly rear in control surfaces axis) so the missile would simply keep gliding at the given direction unless any external force is changing it?

It is just odd that the missile receives a slight corrections upwards to just keep it up, instead getting "nose heavy" and start drooping downwards.

I could see a bug in a safety mechanism that there is no self-destruct in the last moments when the battery is to run out, so it will blow the missile instead let it just fall from the skies?

As for the DSR, again according to documentation, it goes from 22nm to 38nm (or 32, I'm going by memory so the exact number is fuzzy) vs that 2m^2 target when using PD illumination.

Please publish the documentation for all to see.

Is it possible that after the hydraulics are gone, that the control surfaces are "stuck" to optimal aerodynamic position (aerodynamic center should be slightly rear in control surfaces axis) so the missile would simply keep gliding at the given direction unless any external force is changing it?

I don't know. With the hydraulics gone they just might be freewheeling.

It is just odd that the missile receives a slight corrections upwards to just keep it up, instead getting "nose heavy" and start drooping downwards.

I would consider this a bug. It's also possible that the missile is still a point mass in the simulation despite all the other stuff.

I could see a bug in a safety mechanism that there is no self-destruct in the last moments when the battery is to run out, so it will blow the missile instead let it just fall from the skies?

Maybe, maybe not. That's more like a decision. I haven't checked anything regarding self-destruct systems. The impact fuze, once armed, may be enough to destroy the missile once it lands. Either way, this would hide other issues if implemented.

Please publish the documentation for all to see.

I'm not allowed to do that. I did however verify the following data of the AIM-7F:

For a 5m^2 target, CW range is 29nm, PD is 38nm. This tracks with the 2M^2 figure, which doesn't really apply to DCS anyway.

With PD you'll be hard pressed to exceed the DSR cue range aerodynamically in almost any scenario WRT F-15.

I don't know. With the hydraulics gone they just might be freewheeling.

 

 

I would consider this a bug. It's also possible that the missile is still a point mass in the simulation despite all the other stuff.

 

 

 

Maybe, maybe not. That's more like a decision. I haven't checked anything regarding self-destruct systems. The impact fuze, once armed, may be enough to destroy the missile once it lands. Either way, this would hide other issues if implemented.

 

 

 

 

I'm not allowed to do that. I did however verify the following data of the AIM-7F:

For a 5m^2 target, CW range is 29nm, PD is 38nm. This tracks with the 2M^2 figure, which doesn't really apply to DCS anyway.

With PD you'll be hard pressed to exceed the DSR cue range aerodynamically in almost any scenario WRT F-15.

Good find. All the evidences are here. I think this post could be moved into the bugs sections now.

Good find. All the evidences are here. I think this post could be moved into the bugs sections now.

I don't have the track file, only the ACMI file from the Tacview. I don't believe it is enough for bug report.

I did however verify the following data of the AIM-7F:

For a 5m^2 target, CW range is 29nm, PD is 38nm. This tracks with the 2M^2 figure, which doesn't really apply to DCS anyway.

With PD you'll be hard pressed to exceed the DSR cue range aerodynamically in almost any scenario WRT F-15.

I have never been able to make a supersonic launch on any fighter at less than 18 nm head-on at 22 kft or lower. Not sure if I'm doing something wrong, but the same data shown as posted by OP (full source here) shows the AIM-7F locking on a 2 m^2 target at 20 nm, both at Mach 0.9 at SL so it's pretty close. Testing also shows that at 42 kft, I could hit a hot, passive, non-defending, Mach 0.9 co-alt F-15 with the AIM-7F/M/MH launched at Mach ~1.25 at 22 nm or so, which means that matches the data closely... Except the detection range is a actually a bit underpowered because I doubt a head-on F-15 with no jamming would show up as something tiny like 2 m^2. Was this long launch that you saw done by an AI F-15, Fri13?

But it doesn't matter right now because you can dodge an AIM-7 while rolling hot at 5 G at short range and at ranges where it runs out of fuel, you can lazily pull 4 G (don't even need to roll) while hot on the launching aircraft and the AIM-7 will just miss. Hoping this gets fixed soon.

I don't have the track file, only the ACMI file from the Tacview. I don't believe it is enough for bug report.

We don't work for ED. The evidence is there, now it's ED's responsibility to investigate with or without further documentation.