ah64a WIP..Please use the release version

You can attach weapons and missiles to your aircraft, this is not against the rules. You could also fire them but at some point you'll have to put a caution message on the download to make children and their parents aware that this may not be a product for them. I'm not sure where the line is drawn here and different countries have different rules, too. But this is your aircraft we're not stopping you from putting some external things on it.

Pretty sure that this has to do with the performance savings related to the EC 135 helicopter on mobile. Previously we used a higher internal physics update rate. Now that has been reduced to the same as the airplane update rate. Physical connections that are really stiff and barely worked before will now blow up to infinity within milliseconds and the sim detects that resets the aircraft. This death loop is what's causing the black screen as the graphics doesn't get valid data for rendering the aircraft.

If this is the case during aircraft development you have to decrease the joint stiffness (K and D values) of all connections until the issue goes away. The reason behind this is that the combination of high K and D values and very low masses (e.g. K>100000N/m and Mass < 1kg) causes oscillations of very high frequency which cannot be resolved by the physical time steps.

If you're using our new turboengine simulation that too can blow up to infinity if the "Rho" values are set too high. In that case the engine computes a very quick pressure increase and the pressure starts oscillating eventually blowing up to infinity.

I'll take a look at the chopper. Over the years you kinda get a gut feeling to detect the trouble making joint or engine parts.

Alright, it's back in the air again.

The issues were caused by two multibody_joint for the left and right gear leg.

I changed this:

            <[multibody_joint][JointFuselageRightGearLeg][]
                <[string8][Body0][Fuselage]>
                <[string8][Body1][RightGearLeg]>
                <[tmvector3d][X0][0.0 1.0 0.0]>
                <[tmvector3d][R0][2.2155 -0.5678 -1.1931]>
                <[float64][Kp][550000.0]>
                <[float64][Kd][11000.0]>
                <[uint32][Type][0]>
            >

To that:

            <[multibody_joint][JointFuselageRightGearLeg][]
                <[string8][Body0][Fuselage]>
                <[string8][Body1][RightGearLeg]>
                <[tmvector3d][X0][0.0 1.0 0.0]>
                <[tmvector3d][R0][2.2155 -0.5678 -1.1931]>
                <[float64][Kp][550000.0]>
                <[float64][Kd][1100.0]>
                <[uint32][Type][0]>
            >

Just decreasing the Kd value by a factor of 10.

And with that it works already.

I also changed some of the other joints where there is no flexibility needed.

E.g. on the vertical tail:

            <[multibody_joint][JointFuselageVerticalTail][]
                <[string8][Body0][Fuselage]>
                <[string8][Body1][VerticalTail]>
                <[tmvector3d][X0][1.0 0.0 0.0]>
                <[tmvector3d][R0][ -9.42614 0.0 -0.39688 ]>
                <[float64][Kp][3000000.0]>
                <[float64][Kd][120000.0]>
                <[uint32][Type][1]>
            >

I changed it to

            <[multibody_joint][JointFuselageVerticalTail][]
                <[string8][Body0][Fuselage]>
                <[string8][Body1][VerticalTail]>
                <[tmvector3d][X0][1.0 0.0 0.0]>
                <[tmvector3d][R0][ -9.42614 0.0 -0.39688 ]>
                <[float64][Kp][0.0]>
                <[float64][Kd][0.0]>
                <[uint32][Type][1]>
                <[string8][InputLock][1.0]>
            >

Which locks the joints which lowers the computation requirements and makes it pretty much impossible for the joint to ever explode. Not something you can do on the gear, where you need it to move. But any other component, even a trimmable horizontal stabilizer can be set up in that way. And it makes it much easier because you don't have to find good K and D values

Quote from delfinpm

Hola Steve

I wonder if the result I have obtained will be of any use to you. This has happened:

1) .- If I load Apache, the screen appears completely black.

2) .- If I have any other aircraft at a certain height flying, I go out, select the Apacho and load it, it is loaded, but it remains completely immobile at that same height. No key has any effect on it, except the Esc key, which I return to the initial screen to shit.

Kind regards: Delfin

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Yes that is what happens when the physics constantly reset. Thanks.

I've done some more work on the Apache and Steve now has the files to evaluate them. I think it flies alright now but I'm waiting on his feedback, being the actual helicopter pilot here

Quote from larrylynx

To put not to fine a point on it

The master has given me loads of homework

But as always, we all need to thank Jan for all he does

Thank you apprentice Larry Lynx.

The Apache is a great helicopter, looks really good already