Control of Flaps and Gear Across full range of movement

[mattford5]

Hello-

I'm guessing this is a flightsim limitation, but does anyone know if there is a way to control the gear and flaps across the entire range of movement. For instance, with flaps, I found that I can only move them via FSUIPC but only to their specfic detents, not move them in 16,383 increments. What I would like to do is to be able to set a flap postion of say 5000 and 5008 as opposed to only being able to set the flap detent values. The same goes for gear: has anyone found a way to address specfic landing gear position across the entire range of movement (ie, extend or partially extend only the nose gear). If anyone has found any workarounds for this sort of the thing, please let me know :-).

Thanks,

Matt Ford

http://www.737sim.com

[Pete Dowson]

... does anyone know if there is a way to control the gear and flaps across the entire range of movement.

Personally, I don't think it is possible.

With Flaps the detentes and their affect on the simulation are defined in the Aircraft.CFG file as you can easily check. I suspect FS uses those figures as they are and doesn't try interpolating between them.

With gear, whilst the motion up and down is tracked, I don't know of any way of stopping it in between.

If anyone has found any workarounds for this sort of the thing, please let me know :-).[\quote]

I suspect you'd need to design an aircraft specifically with these needs in mind, though I still doubt that you could get it actually continuous. The problem isn't so much the graphics -- I expect a clever FS aircraft designer could arrange for the graphic respresentation of some intermediate gear extension to become static, and likewise for flaps. I think the problem is likely to be the way FS is computing the flight model. If it is using pre-calculated tables it is likely to only do this for the known positions rather than take the longer route of computing the characteristics on-the-fly, as it were.

But I may be wrong -- we'd need an FS aircraft expert to confirm or deny.

Regards,

Pete

[mattford5]

Pete-

I suspected as much. I just wanted to confirm it :-). This is all for failure modelling in my 737 simulator. Thanks for the quick reply!

Thanks,

Matt

[Pete Dowson]

This is all for failure modelling in my 737 simulator.

As with many sub-systems and failures, I think the way to simulate such failures is by working out the affect they have and creating that, not the failure itself. For a real in-cockpit simulation, the external look of things (i.e. the aircraft body parts themselves) shouldn't really be the main consideration -- I rarely if ever get out and look -- the screen is outside the front cockpit windows and it seems 'wrong' to look at your own aircraft from there.

So, what you need to consider is what is the effect of such a failure, and cause that to happen. Interfere with the aircraft performance in some way, and so on. Likewise, the actual indications of where gear or flaps are, when shown by, say, Project Magenta, could presumably be interfered with too.

I've not got into really simulating failures much yet, just dabbling on the edge -- like the failure of reversers to deploy when there's a problem with hydraulics, or the possibility of a flame-out in heavy rain/snow unless the engine iginition is set to "continuous". Those things which Thomas and others have been adding to the pmSystems files for the 737NG.

I really don't know exactly what is possible that way, but it certainly seems a lot more likely that you'd get some results by going down that sort of path.

Regards,

Pete

[mattford5]

Pete-

Your suggested methodology is pretty much the course I've been proceeding on my sim (James Price and I co-write our version of PMSystems, called Sim Control). I've been overhauling our hydraulics code and depleted hydraulic resources result in different deployment times of the flaps and gear on the 737, which I was hoping to model. The other malfuction I've been hoping to model is partial gear extentions and gear collapses, hoping that the physics of such a failure (air and ground physics) would be correct in FS, if there would be a way to hack the failure.

One application in particular is the standby hydraulic deployment of the flaps. With normal hydraulics, full flaps deployment takes around 37 seconds. With the standby system, the flaps deploy fully at around 140 seconds, +/- 30 seconds. This is where I was hoping to slowly ramp up the flaps offset to gradually deploy them over time. I found a flaps timing variable in the aircraft.cfg file, but I'm guessing those values are loaded when the aircraft loads, and thus cannot be dynamically modified.

BTW, thanks for adding the reverse failure. There is no backup system on the 737 for that!

Thanks,

Matt

[Pete Dowson]

With normal hydraulics, full flaps deployment takes around 37 seconds. With the standby system, the flaps deploy fully at around 140 seconds, +/- 30 seconds. This is where I was hoping to slowly ramp up the flaps offset to gradually deploy them over time. I found a flaps timing variable in the aircraft.cfg file, but I'm guessing those values are loaded when the aircraft loads, and thus cannot be dynamically modified.

Well, it might be if it could be found. Back in FS2000 days the aircraft wizard Ian Donohoe found loads of stuff -- still mapped (the accelerations and velocities in all six axes, for example). I'm sure he'd know where to look if he was still doing this stuff. It may actually be easier to find in FS98 or FS2000 and then track through FS2002 and FS2004 in the hope that the changes each time are not wholesale. Starting at this end is almost impossible, because the data has become encapsulated in layers of C++ classes and hierarchies. It's all indirect pointers based on class pointers passed in registers, and gets almost impossible to follow. It's an enormously time consuming job, likely many hundreds of hours, and may be fruitless after all. I really can't undertake such things except in areas where I really have to (like the weather, which was a pig to sort out in FS2004).

For slowing flap deployment down, assuming you are simulating an aircraft where you can't hear the flap motors from the cockpit in any case, (as in my 737NG), and you don't need to actually see what they are doing, I guess one way to simulate a slow down would be to pulse the changes with short bursts of interleaved reverse movements. i.e. going from 25 to 30, say, set 30, then 25 briefly, then 30 again, and so on, ending with 30. Adjust the times of each change to increase the time in the proportion you want.

Sounds daft and looks daft, but in the cockpit you might only notice the longer time to deploy.

Regards,

Pete

[mattford5]

Hi Pete-

I completely understand. It's still a mystery to me why MS has to make this so difficult.

Interesting idea on the flaps deployment. Since i'm flying in a real 737 cockpit, I virtually never look via the "outside" view, so your suggestion would probably work. What I might do is simply add a time delay loop on the switch, so it might say wait 30 seconds before moving the flap lever to the next notch.

My hope is that perhaps the next version of FS will support more failures. Even if gear failures were modelled, I'd be a happy man!

Thanks again!

Matt

[Pete Dowson]

I completely understand. It's still a mystery to me why MS has to make this so difficult.

I'm not sure why they wouldn't -- their job is to make a simulator which works out of the box, not a kit of parts for the minority of "real cockpit" builders. They use the techniques which work best for what they need to do.

There are very few programs which one can get into and almost tear apart as much as FS, so at least we should be thankful about that. Look at the horrible monolithic design of CFS3 if you want something really unusable from this point of view -- unlike CFS1 and 2 it wasn't based on FS designs, and I got a real fright that FS2004 was going the same way!

My hope is that perhaps the next version of FS will support more failures. Even if gear failures were modelled, I'd be a happy man!

It may be too late to suggest things for the next version, but write to tell_fs@microsoft.com in any case. Each voice counts.

Regards,

Pete