LJQCN101

Calculating FPM position can be a function of AOA and sideslip only. I'm actually displaying FPM using sideslip and AOA in a module, which is also the way to do I believe in DCS A10C, DCS F15C or DCS M2000 whichever has a FPM indicator. (Although they will build the function into the dll.) You just don't need the vertical velocity to be involved in the calculation. tex_poly.element_params = { "HUD_AOA","HUD_SIDESLIP" } tex_poly.controllers = { {"move_up_down_using_parameter", 0 ,*calculation here*},{"move_left_right_using_parameter", 1 , *calculation here*} }

Thanks. The AOA is basically the angle between the velocity vector and the X-axis (or nose) of the aircraft on the longitudinal axis, so it may be useful when judging ascend or descend. By displaying FPM you can see where you will fly into. Also displayed in an Apache.

Great work! Is it possible to have a FPM on the HUD too? For example, simply calculate the FPM position based on AOA and Sideslip using: sensor_data.getAngleOfAttack() sensor_data.getAngleOfSlide()

Great, sounds promising. Thanks for the update.

Hi. Sorry to bring back the thread but, after an update somewhere before, we got this problem back? Looks like the flaperon still deflects considerably when turning at low speeds & high AOA.

Classically you would need wind tunnel test data to determine whether you've got a reverse control. To determine the effect of rudder in a variety of AoA & sideslip regions, you would need Cl, Cn tables of the aircraft itself which reflects lateral and directional static stability, and the Cl-rudder and Cn-rudder table to evaluate the additional roll and yaw momentum generated by rudder alone. In a F-16 for example, lateral and directional static stability seems to be symmetrical between -20 and 30deg AoA. And from Cl-rudder and Cn-rudder table, reverse control can be observed the following regions: So somewhere between -5 and -10 AoA, with sideslip larger than 6 degs, Cl generated by rudder and by the aircraft itself have a chance to compensate each other, resulting in little roll or opposite roll. Yaw direction will not be changed under negative AoA.

The F-16 do have one, while it simply adds 19.32 * Ay to its yaw FLCS.

Real life video of a F-16 kicking rudder to the left: Being a 3-axis FBW, it does compensate uncommanded roll to a degree, but not that much. (Just one example.)

Cheers. Just my experience in a F15C. I think my stick helped me a lot since I'm using a 22-pound-force X65F and it's wonderful when making small corrections.

For many times, I held the plane at a perfect position for like 10 sec, all lights are in the middle, and I can even plug the refuelling door into the boom myself. And the boom operator just refuses to make a contact. EDIT: Tried one just now. Here the track: LJQCN101 F15C refuel.trk. Took a long time to make a contact.

Roughly stated in the RL manual. Normal main wheel off the ground speed: kg - km/h 23000 - 270 24000 - 275 27000 - 285 to 290 28000 - 295 There's also a chart which you can use gross weight, field pressure, ambient temperature, wind speed to check the exact take-off speed, but I don't think you would need that.

Well, in the RL manual, Operational Limits part, it reads: ACS operation is prohibited at M > 2.0. Reason: Mild oscillation occur.

I beg to differ. Rolling the aircraft at high AOA will create large sideslip due to kinematic coupling between AOA and sideslip, hence should be countered by rudder. But without deflecting the ailerons, you won't have much sideslip buildup, and you create sideslip with the rudder alone? You know that sideslip at high AOA is bad for stabs nose-down ability and departure resistance of the aircraft. So basically you don't want to use either of them alone. eg. Rudder input signal at high AOA is nulled out in a F-16, and is crossfeeded to roll axis in a F-18 (the rudder pedal-to-rolling surface). Currently the DCS Su-27 presents a very strong lateral-directional dynamic stability and you won't even enter into a spin. The aircraft will not punish if exceeding AOA limit or creating large sideslip at high AOA. For ailerons, you want to use it as much as possible to the extent that the rudder is enable to counter all the adverse sideslip. FCS limiting roll rate is largely due to inertia-coupling considerations and the rudder's insufficiency to counter adverse sideslip. The effect of inertia-coupling in real life Su-27SK/J-11A according to the manual (chinese version): Regarding the lateral stick limiter: Actually, lateral stick movement limiter will limit stick travel to 1/3 full range only above 25 AOA, which opposes the current DCS simulation of KF-5 FBW system (which is the same as J-11A). In addition to that, one division of PLAAF who still operates the real Su-27SK (the oldest original Russian version) actually tried DCS Su-27, and reported a lack of roll manoeuvrability at high alpha regions in the simulation.

Just took a look at the DCS manual, the Su-27 roll-yaw crossfeed system do take AOA into consideration: It seems to do the same as the F16's ARI system as both of the systems run as a function of AOA, dynamic pressure and static pressure, since you want different rudder deflection at different AOA/Speed/Altitudes, which is a common sense in flight control design. (More deflection at high AOA, low speeds and high alts.)

I think the Su-27 do have aileron-rudder interconnect system as per described in the manual, but is doing its job ineffectively? In a F-16 for example (which is also equipped with ARI), rudder will deflect much more than aileron to eliminate any side slip build up:

Highly doubted the source. Even with a powerful GE-129 F-16C Block50 with a clean configuration and 34% fuel at SL, it can only do a near 22 STR and 25 ITR, as shown in: https://forums.eagle.ru/showthread.php?t=133922. Also in a MIG-29, it does come with an AOA limiter which allows a maximum of 26 degs, at least in the G model: A clean MIG-29G with 50% fuel at SL can be concluded from the performance chart of GAF T.O.1MIG-29: Max Inst. G: 0.7Mach - 9G 0.6Mach - 9G 0.5Mach - 7.3G 0.4Mach - 4.7G 0.3Mach - 2.6G Max Sust. G: 0.7Mach - 9G 0.6Mach - 7.6G 0.5Mach - 5.8G 0.4Mach - 4.2G 0.3Mach - 2.5G One thing to mention is that in the 0.6-0.7 Mach region, Max Sust. performance of a 50% fuel MIG-29G is even on par with a 34% fuel F-16C Block50 (up to 22deg/s max), both clean and on SL. PS: When reading or drawing an E-M chart for inst. / sust. performance, you basically should go for the G's, not the deg/sec, which is especially unreliable at low speeds.

Or a chart with the same config as Hummingbird's data.

Source: CCTV China. Pretty much resembles the F-18 HUD. Also shows a good glide slope on approach. The speed was 232 km/h maybe?

Yes, that 38 works for both external model and internal model. I've resolved all the animation and key-binding problems of that tech demo BTW. Your code was 100% right. Just something to do with lua and model edm.

Yes. I've just updated it to be compatible with DCS 1.5.2. You can try that again.

Updated to DCS 1.5.2. Please use Github link to download. (https://github.com/uboats/F-16A-Demo-CDMW) CAUTION: Do not directly click on "Download ZIP" in main page. Click on "Latest commit 69ab176"-->Browse Files-->Download ZIP instead to download the latest version.

Hi. What's the AOA value when you have that issue? In CAT III mode, AOA is limited to 15~16deg so you may not have much nose up authority in that mode.

Maybe you can try removing all the files under "F-16A-Demo-CDMW-master\Input" folder and then reassign all the axis in the game.

Hmm...Let me think. So a bit of checklist: 1. downloaded the latest commit, which is 855c288a77134ecdfa225e9c6d88a7f716a9e0d4 2. MOD files are at their proper location. The directory should look like "DCS World OpenBeta\Mods\aircraft\F-16A-Demo-CDMW-855c288a77134ecdfa225e9c6d88a7f716a9e0d4\" if you haven't changed the folder name. 3. Aero Desktop Enabled 4. Fullscreen Disabled (optional if you cannot see the overlay. In most times fullscreen will be OK.) 5. Open the game and notice a "HMCS OFF" displayed on the upper-left corner of the screen.

Try flying at 780~900km/h and trim for that speed where the airspeed trimming law doesn't interfere with the stabilizer anymore and also the aircraft is well before supersonic. At that point you'll feel as if you won't go pitch up and down even with rapid throttle input or accel/decel.