Hummingbird Posted March 18, 2019 Author Posted March 18, 2019 The wings would slow down and ratchet under G. They are looking at it as we speak. For sure, I can imagine ratcheting would be worse the older the bird was.
Hummingbird Posted March 18, 2019 Author Posted March 18, 2019 Not really. Ok, I just figured a worn mechanism could be a little more rough so to speak than a fresh out of the factory one :)
HawkDCS Posted March 18, 2019 Posted March 18, 2019 I mean whether it's implemented correctly. Sorry for the confusion :) AFAIK our documentation says no wingsweep movement above 5G. I'll let the Engineering team chime in as soon as we double check we haven't misinterpreted something. Thanks for looking at it and responding Cobra! I would think they would have to move even at high g loadings. If they couldn’t swing and you accelerated under g you would end up being to fast for the stuck wing position and end up damaging something structural I imagine. If you accelerated from 200KIAS to 500KIAS and they were stuck full forward because u were pulling g I don’t see how the G limits would be higher then 5 since the wings couldn’t move. Only fly GA aircraft but if there’s speed limits on the wings they would have to retract. It was my understanding that them retracting back was to reduce the g taken by the wing and moving it more into the airframe and vortex type lift. Rig: 5960X @ 4.5GHZ 32GB 3000Mhz DDR4 Titan XP Dell 3415W 21:9 Thrustmaster Warthog
Hummingbird Posted March 18, 2019 Author Posted March 18, 2019 Based on the information available the wings should be able to sweep well past 7.5 G's. But at what G load the sweep rate would stall altogether I can't say, however if 4 deg/sec could be maintained at as high as 7.5 G's then it probably wouldn't stall until around 8.5 to 9 G's.
Hummingbird Posted March 19, 2019 Author Posted March 19, 2019 Only fly GA aircraft but if there’s speed limits on the wings they would have to retract. It was my understanding that them retracting back was to reduce the g taken by the wing and moving it more into the airframe and vortex type lift. Yeah that also seems to have been the initial impetus behind having the automatic system as the docs provided by FWind show:
Cobra847 Posted March 19, 2019 Posted March 19, 2019 Documentation can always (unfortunately) be wrong - so if we've used errant data in the implementation, we'll obviously revise. :) Overall though, this should be a pretty easy fix if we verify that it's incorrect. Nicholas Dackard Founder & Lead Artist Heatblur Simulations https://www.facebook.com/heatblur/
Hummingbird Posted March 19, 2019 Author Posted March 19, 2019 (edited) Sounds good Cobra :) With so many systems to keep track of it's completely understandable if an unintended error creeps in occasionally. It's the only beef I have with the FM atm, everything else is excellent. Looking forward to further word on this. Edited March 19, 2019 by Hummingbird
Hummingbird Posted March 19, 2019 Author Posted March 19, 2019 I don't think I've ever been as impatient for something as I am for this haha :D
Victory205 Posted March 19, 2019 Posted March 19, 2019 I don't think I've ever been as impatient for something as I am for this haha :D Hopefully, Heatblur will take their time to carefully research this phenomenon and engage in extensive testing to ensure that it is correct. At least six or seven months to make sure that it right. Fly Pretty, anyone can Fly Safe.
Hummingbird Posted March 19, 2019 Author Posted March 19, 2019 Hopefully, Heatblur will take their time to carefully research this phenomenon and engage in extensive testing to ensure that it is correct. At least six or seven months to make sure that it right.
Eldur Posted March 20, 2019 Posted March 20, 2019 (edited) I've also hd it that Bomb Mode commanded like 68° of sweep instead of 55 unless you got slow and the wings were swept forward of 55°, then bomb mode worked. I think this is not correct at the moment. It goes to 55° or more, depending on the CADC setting / speed - so if you activate Bomb Mode at .92, expect them to stay at 68°. But when they're swept more than 55°, they never come forward when slowing down. I understand they should though. As the aircraft accelerates and the auto wing-sweep schedule is intercepted, the wings will follow the auto schedule even though the switch remains in bomb mode. Upon decelerating, the wings will sweep forward to 55° and stop. Edited March 20, 2019 by Eldur
FWind Posted March 20, 2019 Posted March 20, 2019 Hopefully, Heatblur will take their time to carefully research this phenomenon and engage in extensive testing to ensure that it is correct. At least six or seven months to make sure that it right.
Hummingbird Posted March 20, 2019 Author Posted March 20, 2019 (edited) Edited March 20, 2019 by Hummingbird
Hummingbird Posted March 21, 2019 Author Posted March 21, 2019 Another place mentioning the same 7.5 deg/sec in level flight and 4 deg/sec at 7.5 G's: http://www.dept.aoe.vt.edu/~mason/Mason_f/VariableSweepS06.pdf
Hummingbird Posted March 21, 2019 Author Posted March 21, 2019 This paper (below) by one of the engineers who helped design the wing box and pivot section, also hints at the wing sweep being operable throughout maneuvering envelope of the aircraft: A great read through and through btw.
Curly Posted March 21, 2019 Posted March 21, 2019 The natops says, "Maximum wing-sweep rate (approximately 15 per second) is adequate for most transient flight conditions; however,wing-sweep rate can be significantly reduced or stalled by negative-g or large positive-g excursions. Sufficient capability has been provided in the system, consistent with the sustained performance capabilities of the aircraft.". https://books.google.com/books?id=J-8cAgAAQBAJ&lpg=PP1&pg=SA1-PA76#v=onepage&q&f=false The older version of the flight manual manual gets more detailed, noting. “Critical performance conditions occur at low linear deceleration/ acceleration of the aircraft under high g’s (split-s or loop maneuvers) and at high linear deceleration/acceleration under low g’s (steep climbs with low thrust or steep dives with maximum thrust). The rate of operation during unsweeping motion exceeds that during sweeping motion at elevated positive load factor conditions. Because of the attachment geometry of the wing sweep actuators, the rate of sweep progressively increases with the wings aft of 50 degrees. Failure of either the combined or flight hydraulic system permits the wings to move at a reduced rate (nominal 3 degrees per second under 1 g conditions).” https://www.avialogs.com/images/photos/docs/694/3368/preview/3368-p131-normal.jpg It seems the maximum sweep rate quoted in the slides, 7.5 deg/sec in level flight, is low. Also since the sustained turn performance of the craft is over 6 g it seems reasonable that the wings should continue to unsweep over 5 g. https://a.disquscdn.com/uploads/mediaembed/images/4046/6189/original.jpg
Hummingbird Posted March 21, 2019 Author Posted March 21, 2019 It seems the maximum sweep rate quoted in the slides, 7.5 deg/sec in level flight, is low. Also since the sustained turn performance of the craft is over 6 g it seems reasonable that the wings should continue to unsweep over 5 g. Perhaps 15 deg/sec only relates to manual operation?
FWind Posted March 21, 2019 Posted March 21, 2019 Perhaps 15 deg/sec only relates to manual operation? Have you remember it? https://forums.eagle.ru/showpost.php?p=3260515&postcount=61
Curly Posted March 21, 2019 Posted March 21, 2019 (edited) Have you remember it? https://forums.eagle.ru/showpost.php?p=3260515&postcount=61 Do you have figure 3, that’s mentioned in section 17 of that document? Perhaps 15 deg/sec only relates to manual operation? The 2-2-4 provided by Fwind is interesting, it’s the Flight Control Systems Principles of Operation manual from the Navy. What it says is that you can command a rate of 15 degrees a second but the most the system will give you is 7 degrees a second. “Although either command has a wing sweep rate of 7.5 or 15, the wing, due to the hydro mechanical system drive will only sweep at the rate of 7 per second.” It goes on, but I’ll paraphrase. The reason you can command a rate of 15 degreees per second is so that you don’t have to hold the button the entire time the wing sweeps. With this system you don’t have to have to hold the button for 4 seconds to command the wings to sweep 30 degrees, just 2 seconds. However it will still take at least 4 seconds for the wing to travel those 30 degrees, because at best it can only traverse at 7 degrees per second. Edited March 21, 2019 by Curly
Hummingbird Posted March 21, 2019 Author Posted March 21, 2019 Yes, I'm thinking that if the sweep rate wasn't even halfed at 7.5 G's, then the system was able to operate comfortably out to atleast 8 G's at most weights. But without specific figures like those provided by Mike Ciminera we can't say for sure. As he was one of the designers behind the aircraft I find it highly unlikely he would post incorrect information however.
FWind Posted March 22, 2019 Posted March 22, 2019 Do you have figure 3, that’s mentioned in section 17 of that document? The 2-2-4 provided by Fwind is interesting, it’s the Flight Control Systems Principles of Operation manual from the Navy. What it says is that you can command a rate of 15 degrees a second but the most the system will give you is 7 degrees a second. “Although either command has a wing sweep rate of 7.5 or 15, the wing, due to the hydro mechanical system drive will only sweep at the rate of 7 per second.” It goes on, but I’ll paraphrase. The reason you can command a rate of 15 degreees per second is so that you don’t have to hold the button the entire time the wing sweeps. With this system you don’t have to have to hold the button for 4 seconds to command the wings to sweep 30 degrees, just 2 seconds. However it will still take at least 4 seconds for the wing to travel those 30 degrees, because at best it can only traverse at 7 degrees per second. The figure 3 have nothing about sweep rate at high Gs.
Hummingbird Posted March 22, 2019 Author Posted March 22, 2019 I guess getting hard data on this is proving quite a task for the devs, otherwise we would've probably heard from them by now. I wonder if its possible to inquire Mike Ciminera about it, providing he's still alive. Might be worth a shot.
Cobra847 Posted March 23, 2019 Posted March 23, 2019 Wingsweep limits tweaked and will now sweep beyond 7.5G Thanks for raising this to our attention! Nicholas Dackard Founder & Lead Artist Heatblur Simulations https://www.facebook.com/heatblur/
Hummingbird Posted March 23, 2019 Author Posted March 23, 2019 (edited) Wingsweep limits tweaked and will now sweep beyond 7.5G Thanks for raising this to our attention! Thanks Cobra, was my pleasure :) PS: When can we expect this update to hit? PPS: You guys rock! Edited March 23, 2019 by Hummingbird
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