Bristol F2B Turn While Taxiing Problem

#1
First off, I apologize if this is the incorrect place to post this, but I don't know where this question would be better posed.

One of the Virtual Airlines I belong to is going to have an event commerating the end of hostilities in "The Great War", World War I. We are going to do a fly-in/fly-over with vintage WWI aircraft. I have found working models, with virtual cockpits for FS2004, FSX, and some that say they will work in P3D; a Fokker DRI, a Fokker DVII, an Albatross DIII, a Pfalz DIIIA, a Sopwith Camel, a Vought VE-7, a Spad, and a Bristol F2B. I have been testing these in FSX SP2. Several had taxiing problems since the majority used skids and not tail wheels, but I have fixed them slowly one by one.

The Bristol F2B is giving me fits, though. No matter what changes I make to the aircraft.cfg file she will only taxi in a straight line, so you have to slew to the runway to takeoff. I have checked to make sure there is no tail_wheel_lock parameter set to "1". Of all the aircraft, this one did have a rudimentary braking system, so I have tried setting differential braking. The contact point for the tail skid has the number 8 position set to 60 degrees, so she should turn...but she doesn't.

I downloaded her from Simviation here, https://simviation.com/1/search?submit=1&keywords=F2BPROJ.zip&x=22&y=11

Any ideas on what I have done wrong...or what the modeler did wrong?

Randy
 

Heretic

Resource contributor
#2
First off, I apologize if this is the incorrect place to post this, but I don't know where this question would be better posed.
Avsim, Flightsim, Simviation, Sim-Outhouse...honestly, the way your're asking puts this a bit too much in the "product support" domain, something which absolutely do not want in a developer forum. We don't really want to look under other aircraft's cowlings other than out own.

The modeler has absolutely nothing to do with the flight dynamics.

Here's the contact point reference. The issue has to be in there somewhere.
https://msdn.microsoft.com/en-us/library/cc526949.aspx#mozTocId836373
 
#3
You are absolutely correct, Bjoern. My apologies. I did post this identical query over at AVSIM to get more "visibility" for my question. I'll follow any replies over there. Please forgive me.

Randy
 

Heretic

Resource contributor
#4
It wasn't meant personally, but I'd rather break out the hammer sooner than later (to discourage others to follow the samer example) to avoid getting flooded with inquiries about commercial products that none of us owns.

And I did point out the SDK document. Use it as a reference to sanity check the contact points.
 
#5
I knew that, and completely understood and agreed. No worries. I did check the contact points. Although I appreciate the link to the SDK ESP I have had that as a "Bookmark" for years, but thank you.

Yes, I did look at the contact points. That's how I knew parameter position 8 was set to 60 degrees. Here is the full contact point entry...

point.0 = 3, -13.1, 0, -3.17, 1200, 0,0, 60, 0.2, 2.5, 0.7, 0, 0, 0, 0, 0
"3" at PP1 means it's a skid, not a wheel. The zero at PP 6 means no brakes and the one at PP7 is zero because it's a skid with no diameter (although I did try changing it to a wheel with a 6 inch diameter to no avail). PP8 we know and the rest are really not relevant in my mind to the issue, but who knows. My mind sometimes leads me astray. Let's see what happens over at AVSIM.

Randy
 

Roy Holmes

Resource contributor
#6
A tail skid provides some measure of directional stability when taxying on grass, but no steering. To steer you have to use rudder and a blast of prop thrust.
Roy
 
#8
I solved it by cheating...somewhat... Roy's method worked, albeit the turns were rather "large" by that method. I simply renamed the tail skid contact point to a wheel with a diameter of 6" and she turns on a dime now with rudder deflection, even though in sim the "wheel" looks remarkably like a skid... ;) I had tried the "wheel" method before...as noted above...but only in giving the "skid" a diameter, not actually changing PP1 from "3" to "1".

All is good in Vintage-ville. Thanks for all the advice and help. This can be closed and locked by a moderator if you choose...or deleted entirely since it is really a wandering outside the intent of FSDeveloper.

Randy
 

Heretic

Resource contributor
#9
Deleting the thread would also delete my very educational rant about product support.

Glab you solved it.
 
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