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Super Grover

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Posts posted by Super Grover

    How to win at BFM in the Mighty F-4E Phantom

    in DCS: F-4E Phantom

    Posted · Edited by Super Grover

    Sadly, there's no simple answer to this. First of all, with all the information I have, I wouldn't call the linked picture a reliable source. Then, the question is what alpha are you interested in - is it wing or fuselage (different F-4 sources use different references for that)? Then there's that constant issue of the conversion between the AoA in units and degrees - and this is probably the most challenging question we had to answer to properly use the resources when working on the FM of the F-4E. Finally, there are very significant differences between wind tunnel data and flight tests, and the in-flight calibration of the production AoA measurements was probably one of the issues. Finally, the problem is the definition of the stall point and how the stall is approached, which significantly impacts how the aircraft behaves. It was easier to test and collect the point when the aircraft departed.

    Back for a moment to the attached plot - according to McDonnell, 1G departures for the base wing F-4E could happen as low as at 19° of wing AoA - so lower than what is presented in that graphics.

    And after this too long introduction 😆, when I drew all the uncertainties and how one should take all those numbers with a grain of salt, I can write that the slatted wing stalls/departs around 3°+ later than the non-slatted wing.

    • Like 2

    Force Feedback Settings Discussion

    in DCS: F-4E Phantom

    Posted

    On 5/19/2025 at 10:03 AM, Bog9y said:

    Hi Super Grover, did you get a Rhino in the end? 

    Yes, but I haven't yet finished the FFB review pass, as other items were prioritised. However, I'll probably return to this after the next update is published.

    • Like 2
    • Thanks 3

    Stick pitch reaction slow

    in DCS: F-4E Phantom

    Posted

    Quite possibly, yes. The bellows-bobweight stick forces would be just a bit higher than the friction forces and relatively small to other flight regimes.

    The figure below comes from a publicly available document: VALIDATION OF THE FLYING QUALITIES REQUIREMENTS OF MIL-F-008785A (USAF)

    nullimage.png

    It's for the B version, but the changes between the systems were minimal and shouldn't impact the bellows behaviour at this speed. Higher speeds are not visible here, but you can extrapolate and roughly get the idea of how much they would increase at high speeds.

     

    Note that the takeoff pitch controls will change in the next update as we added a more detailed stabilator simulation close to the ground, significantly improving and simplifying handling and making it more realistic.

    • Like 5
    • Thanks 2

    Stick pitch reaction slow

    in DCS: F-4E Phantom

    Posted

    The topic is slightly more complex. The stick behaviour on the ground, including the animations, is in a special mode due to the system's physical properties, which otherwise would cause confusion and unrealistic visuals. Based on feedback from our testers, we introduced this mode before the release. The most crucial difference is the lack of friction forces (or no direct control over them from DCS for FFB sticks), while friction is the most prominent force on the ground.

    We simulate the non-friction for FFB sticks on the ground; it's just that they are very small compared with those in flight. On the ground, the difference in force between the most forward and the most aft stick position is less than 5 lbf. At 220 kts, it should be close to 18 lbf. For 350+ kts, that difference can easily reach 80-100 lbf. So we assume that 40-50 lbf in each direction corresponds to the max force from the FFB and scale all forces proportionally. It means that on the ground, the commanded force may be below the threshold for your FFB stick to react. You may want to set a nonlinear function for the force in your FFB driver, but we may also add a slider for fine-tuning of the FFB linearity as a quality of life feature in one of the future updates.

    • Like 1
    • Thanks 1

    Crash/Hang spawning into the Phantom

    in Bugs & Problems

    Posted

    The log file suggests a problem initialising Jester sound samples, which indicates that the whole directory with the samples was missing. I assume it works now, so we won't investigate it, but if the problem reappears, please let us know, and we will check what could cause it. For the time being, have fun with the F-4E 🙂 

    WSO lag and Pilot getting full desync errors on touching anything in the back

    in Bugs & Problems

    Posted

    I identified one - and hopefully the only - source of such desyncs. As a temporary workaround, please ensure that both clients (the pilot and the WSO) use the same settings for the special option "Use Radar Antenna Hand Control also for Radar Cursor Control Panel" - unchecked (default) for both; or checked for both. Also, please let me know if you keep getting the desyncs despite the same options for both clients.

    • Thanks 2

    2.9.5.55918 (MT) Flaps airspeed switch set incorrectly

    in Bugs & Problems

    Posted

    Is your observation based on a single flight or multiple attempts? Did you fly a worn-out aircraft or maybe a reference aircraft? As you noted, the value isn't precise so you might have gotten into an airfame which had those values lower. Poor quality and wear and tear also change the threshold values of the blow-up switches.

    I checked the code, and the mean values are 237 kt for accelerating and 222 kt for decelerating. So, at least, we can confirm that the code should work as in the manual. If it does not, we will make sure to find out why and fix it.

    • Like 1

    Hydraulic System Not Fully Modeled?

    in DCS: F-4E Phantom

    Posted · Edited by Super Grover

    Thank you for your message, @Ludl0w.

    Yes. Some aspects of the hydraulic systems simulation haven't been enabled yet as they are among the most complex systems and influence multiple other components. A potential bug could render the entire aircraft unflyable, so we decided to play it safe for the release. There are also other aspects of the hydraulic system modelling that need to be finished, and proper hydraulic leaks are in that group. They aren't on the shortlist for the next update, but it won't be long before those features are released.

    • Like 4
    • Thanks 2

    Elevator trim too aggressive

    in Bugs & Problems

    Posted

    17 minutes ago, kablamoman said:

    How is it trollish to point out that the behavior of the aircraft is obviously showing that the stab and the stick are not under direct control of the pilot in the non-FFB implementation? The virtual pilot releases grip strength and allows the stick/stab, and thus the entire aircraft to oscillate freely about the neutral point in pitch.

    You guys keep asserting that the effect is only a visual artifact of the stick animation, but it is clearly not.

    I believe it is a pretty severe oversight. I paid for the module just like everybody else posting in the bug forum with feedback and suggestions.

     

     

    I'm sorry you are disappointed with the module. However, that disappointment can't justify spreading misinformation. If you believe that we did anything incorrectly, please get in touch with our customer support with your order number to check what options are available for you.

    • Like 8

    Elevator trim too aggressive

    in Bugs & Problems

    Posted

    2 minutes ago, kablamoman said:

    I suppose it's just coincidence that the stab and aircraft attitude bounce around and oscillate along with it then.

    I don't know. I was taught that false implies everything and anything. IMO, it's just a waste of everyone's time to conclude on incorrect assumptions.

    Elevator trim too aggressive

    in Bugs & Problems

    Posted

    1 hour ago, Hunter2.1 said:

    I think the no comments from developers about this graph, even on 2 threads, says a lot) it's revolution, Johnny 🤣

    I wrote in the other channel that the animation arguments are NOT directly related to the actual stick position and shouldn't be used for any aircraft behaviour comparison. The chart above was created after my post, but the animation arguments were still used to plot it. I can't forbid anyone from having an opinion about that plot, but the methodology of analysing the controls presented is incorrect. As promised, I'll prepare an in-depth explanation of what we do and how we do it, but the queue of more urgent tasks is long, so that it may take a bit longer.

    • Like 8
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