This is the 3rd flight in the row since I installed the 1.0.4 patch and something is seriously screwed up. I takeoff VTOL, transition, cruise and descend just fine, but as soon as I start to transition the nacelles back to helicopter mode for landing suddenly the nose goes for the sky and I severely lose attitude control. The aircraft is retaining control of the cyclic vertical axis and despite having my real cyclic pushed all the way forward, the axis it at maximum in the opposite direction. I have not been able to complete a flight on 1.0.4 yet. These problems did not happen on 1.0.3.
Miltech Simulations @MiltechSimulationsTwo things that could be resulting in this problem (btw - I’ve been flying multiple times just fine and this issue has not been reported, based on that I would assume that the flight dynamics don’t have any bugs).
On v1.0.4, trimming on CONV has been improved. It could be that your aircraft is trimmed up and as soon as conversion starts, the change in thrust vector + trim inputted results in a severe nose up. Pitching down the aircraft should resolve the issue - I would also strongly suggest always start conversion with elevator pitch at 0, as pitch between APLN mode and CONV does not always translates well.
Verify that Autopilot is fully disengaged. Autopilot won’t work great during CONV as the change in thrust vector is not supported by MSFS Autopilot.
Finally, make sure that your flight model is set to “MODERN” and assistance settings are “VOLOCOPTER” (set by default). The new APLN aircraft model uses CFD simulation which requires Modern flight mode to be enabled.
- KIn reply tokawfeebassie⬆:@kawfeebassie
I have done dozens of flights in the Osprey since the initial release. The v1.0.3 patch was working very well for me and I was very satisfied with how the aircraft was behaving. The relationship between speed, power and the nacelle angles seemed to have been resolved, the autopilot was working very well... I flew a couple of dozen flights perfectly. As noted, the problems with v1.0.4 are severe. The aircraft has become unflyable for me. Given that the patch was only released yesterday, I suspect that other pilots who may also experience this issue have not had a chance to experience the problem yet. I have now experienced the exact same behavior on 3 separate flights.
I always disengage the autopilot before starting transition, so I am hand-flying the aircraft in stable flight with power and pitch set to maintain altitude and an airspeed below 200 kts. I start to transition the nacelles forward usually around 185 kts. Since v1.0.4 the behavior immediately after I start transition now is severe, the nose pushes straight up and there is nothing I can do to stop it.. Something other than me is altering the pitch, and the change is severe. I did notice that the Altitude Hold button LED remains lit, even after disengaging the autopilot. Clicking the button manually does not extinguish the LED. I tried engaging and disengaging the autopilot multiple times trying to reset while experiencing the pitch problem, but it did not help.
Miltech Simulations @MiltechSimulationsThe update was released on the 29th of November, this is the 1st report so far - yesterday’s update just edited a couple of textures (hotfix patch).
Very likely the issue is related to AP Alt Hold being engaged. I’ll investigate further.
- K@kawfeebassie
I realize how difficult it is to fix something you cannot reproduce. I just tested the v1.0.3 patch you sent me with the last approach I had problems on, and v1.0.3 flew fine for me. I will continue to to test v1.0.4 and see if I can help provide more information... maybe I can record a short video demonstrating the problem between the patches as well. Thank you, I appreciate the support and want to help as much as I can.
@nenenuiI did some 1.0.4 flights today and I did not run into this "nose up" problem so far … during those 5 fights (landings).
- Miltech Simulations @MiltechSimulations
I've done multiple tests on 1.0.4, these are my findings:
- I've been unable to replicate any pitch up problems transitioning from APLN to CONV. No matter what I did, the aircraft behaved as expected. The only time I had a severe pitch up was trimming the aircraft up before conversion, as expected.
- I've been unable to replicate ALT Hold LED remains on after deactivating the AP. I've tried both using the controller command and clicking on the cockpit button - both fully deactivate the AP for me.
- I tested transitioning to CONV with the AP fully activated (ALT HOLD). The aircraft loses some altitude, but the AP kicks in and corrects back to the selected altitude instantly. No Pitch up.
- I tested with the Legacy flight model (not recommended) - the aircraft behaves as expected.
- Tried APLN-CONV at different speeds, behavior as expected
- K@kawfeebassie
I don't have time to do it today, but tomorrow I will create you a video with v1.0.3 and then v1.0.4 demonstrating the issue.
- K@kawfeebassie
Just an update that I didn't have time to test this on Sunday. I did a short flight with a friend with v1.0.4 and did not reproduce the behavior on that flight, but I was flying VFR and did not make extensive use of the autopilot during that flight. Of the 3 flights where I had the problem, one was a visual approach into Atlanta, and two were an instrument arrival/approach to catch the ILS in Geneva.. All of them was making use of autopilot including speed mode, hdg mode, nav mode, VS and ALT hold. As soon as I can, I will try to test again into Geneva. I feel it has to be related to the use of the autopilot not deactivating either a speed or altitude related mode correctly and continuing to try to trim the aircraft while I am both trying to descend and slow down would both induce an attempt to trim the pitch up.
I appreciate that you tried to reproduce the problem. I realize at this point that unless I can provide steps to reproduce or at least demonstrate it with a video capture, that there is nothing you can do. If this had only happened once I would not have submitted it. It happened to me on 3 flights in a row... but as I mentioned, I did a short flight yesterday and did not experience the problem again. If I can gather more information, I will post more information when I can.
- DIn reply tokawfeebassie⬆:ADP @Daywalker03
I was experiencing the same issues with the aircraft going nose-up when transitioning from flight to VSTOL/STOL to land this afternoon. Updated to 1.40 and it appears to be working correctly,
- Miltech Simulations @MiltechSimulations
Interestingly, for the other customer who reported the issue, it only occurs on V1.0.4, while for you it occurred with previous versions. Still a mystery to me as I've been unable to replicate it (unless I trim the aircraft excessively)
- KIn reply tokawfeebassie⬆:@kawfeebassie
I have done a dozen flight now in v1.0.5 - no more issues.
- Progress
- K@kawfeebassie
So I was able to reproduce it again this morning, but I didn't capture a video. I will try again and record it now that I have a better idea of how to induce it by pushing the aircraft into a stall condition by rapidly decreasing the nacelles and speed of the aircraft at slow speeds.
I came across this note in the MSFS AAU beta release notes. I don't fly the AAU beta, but I was looking at with regard to upcoming avionics updates and noticed the item regarding loss of cyclic control. I don't know whether this could impact the Osprey or not but I wanted to identify it since it certainly reflects the behavior I am seeing.
- Miltech Simulations @MiltechSimulations
The Osprey doesn't use the Helicopter flight model (it's incompatible with thrust vectoring, wouldn't work with the Osprey). Instead, the Osprey is modeled as a "volocopter", which uses a custom flight model and assists are disabled by default.
This update shouldn't affect the Osprey, but hey, who knows.
This bug continues being a mystery to me. Seems to be isolated to your system - has not been reported by any other customer, and I've been unable to replicate after multiple flights.