Bucking Shorts 360

[SSI01]

I've installed the Virtualcol Shorts 360 and its companion aircraft and am finding it to be an enjoyable package. One small gripe about this bird is something it has in common with a number of turbo-prop powered aircraft - it either charges down the taxiway at 40-50 KIAS or sits still on the same taxiway - there is no happy medium with quite a few of these turboprop aircraft. On this bird, animation allows one to set the airplane down upon landing and then pull back a positioning lever on the throttle quadrant that moves the throttle setting back to "ground" position from "flight" position. I've also set the fuel condition levers to "idle" and the prop levers to "idle." The aircraft will come to a complete standstill on the runway. A slight - and I mean VERY slight - nudge of the throttles on the joystick results in a neck-snapping rise to the nose followed by a gallop down the taxiway. A stomp on the brakes stops the bird, sending its nose diving toward the pavement. Using "F2" and "F3" to slow and speed up the throttles has the same effect, there is no gentle way to set this thing up to taxi gently at from walking speed to, say, 10 KTS on the taxiway.

I remember having this problem with the KBT P-3 as well, but some editing of the aircraft's .cfg file was necessary and the problem disappeared. Does anyone know or remember if some numbers need to be changed in either something having to do with the propellers, or is it the throttle effectiveness?

I'm going to make a printed file of the fix and file it in my MS maintenance folder if that fix can be found.

Does anyone have any ideas?

[BendyFlyer]

Not sure about this bird but the FSX turboprop ground pitch issue is common to most and few have come up with a completely satisfactory fix or work around. The matter of the aircraft on the ground is two fold the gearing ratio of the engine fitted and the beta range of the propellers. In real turboprops the ground speed is handled by beta range which can be finessed back and forth (effectively moving the propeller blades from a thrust pitch to neutral and slightly negative, the other control is via the condition levers which should be adjustable from low idle to flight or high idle. Some engines for example had no reverse like the RR Dart so those aircraft relied completely on the braking systems. From my experience with another VirtualCol turbo, the Otter it took a lot of work both with the air file and the config file to get the engine and prop parameters correct but that was a PT-6 engine, you can have a look at the upload of the fixes I did for the TurboOtter I posted here at SOH to get some ideas.

The best ground control and speed control via the props I have seen in FSX was Milton Shupes Dash-7, just the occasional F2 to get the beta keeps it humming along nicely so you might want to have a look at the config and air data there. The reason I mention the air files is that you can only do so much with the config files but as it is a VirtualCol model you can guarantee a lot of the prop and engine values will be out of whack or incorrect for the aircraft type and engine. Chasing down this data from web sources and manuals can be a real pain.

Good Luck.

[SSI01]

Thanks BF. Looks like I'm off on my paper chase in the .cfg files.

[SSI01]

Bendy Flyer - what is the best program available to open an .air file with?

[narah]

i have used aam, aircraftairfilemanager, and fixed this issue with adjusting parameter 511 in .air file.
The first 3 blade pitch x values coresponds to negative y values. I have changed this to at least 0 y values.
Modified the CS C-130 and the AS TwinOtter that way and i am happy with the result.
Best regards







I've installed the Virtualcol Shorts 360 and its companion aircraft and am finding it to be an enjoyable package. One small gripe about this bird is something it has in common with a number of turbo-prop powered aircraft - it either charges down the taxiway at 40-50 KIAS or sits still on the same taxiway - there is no happy medium with quite a few of these turboprop aircraft. On this bird, animation allows one to set the airplane down upon landing and then pull back a positioning lever on the throttle quadrant that moves the throttle setting back to "ground" position from "flight" position. I've also set the fuel condition levers to "idle" and the prop levers to "idle." The aircraft will come to a complete standstill on the runway. A slight - and I mean VERY slight - nudge of the throttles on the joystick results in a neck-snapping rise to the nose followed by a gallop down the taxiway. A stomp on the brakes stops the bird, sending its nose diving toward the pavement. Using "F2" and "F3" to slow and speed up the throttles has the same effect, there is no gentle way to set this thing up to taxi gently at from walking speed to, say, 10 KTS on the taxiway.

I remember having this problem with the KBT P-3 as well, but some editing of the aircraft's .cfg file was necessary and the problem disappeared. Does anyone know or remember if some numbers need to be changed in either something having to do with the propellers, or is it the throttle effectiveness?

I'm going to make a printed file of the fix and file it in my MS maintenance folder if that fix can be found.

Does anyone have any ideas?

[BendyFlyer]

Bendy Flyer - what is the best program available to open an .air file with?

There is a great little program on the net called AirEdit152 the author is YahiaAlWajid (AirEdit152YahiaAlWajid.zip) and an update (aired152_update806.zip) it is simple and easy to use and there is a manual of sorts included. I cannot remember where I found it but if you cannot find a copy I could upload it here I guess.

[BendyFlyer]

SS101, you will need the type of propeller and turbine (turboprop) to get the correct values for blade length, section, pitch range etc. And the same for the engine itself. Usually you will find this information in documents relating to type certificates and or modifications submitted to or held by civil aviation regulatory authorities. Sometimes you cannot get completely accurate data so you may have to try various changes in the engine and propeller data to come up with a combination that works. This is because of the way the FSX engine processes the basic parameters of the air file and aircraft config files. For example the piston engined Otter was a variable pitch prop not a constant speed unit which MS FSX basically had not built into their program (because it is very rare), it took about a dozen changes to finally get the power and gearing parameters to the point where what was being indicated was correct to the real thing. With the turbine otter there were a lot of models about with PT-6s (Beech King Air, Dash 7, Twin Otter, Cessna 208 etc), so I had a good cross comparison plus the proper engine and prop data to work with. I have not checked what engine was in the S360 but it did have unusual propellers (lots of blades).

I think the thing with propellers is this, two blades will always produce the most power or thrust but they have to be bigger and bigger for bigger engines to the point where from an air frame design perspective it is not feasible or possible. More blades produced a heavier propeller assembly but allows you to use more and smaller blades and you also get a quieter prop/engine combination. Blade theory is a very arcane science and it is not widely appreciated that all blades are an airfoil section with a thick chord and thin tip and this aspect is not well understood in the simulation world but if you look at the SDK for FSX you can see that a lot of variables or parameters are catered for but just not used. Then again because of the FSX engine limitations a lot of designers can get the 3D hull wing shape right etc but overlook the engines. It is one of the reasons I have the greatest respect for sim model builders and developers doing this electronically is just like building the aircraft and powerplants from scratch it is an enormous amount of work.

And beware the net, there is a lot of data about which is incorrect and you need to reference official published data. I have found this problem with numerous types where somebody got it wrong and this error becomes transferred across multiple sites. I hope I have not dissuaded you but it is part of the bag but if you get it working right you will enjoy the effort.