Tailwheel Lock

[Moses03]

I have added the tailwheel lock entry under the contact points section but the wheel still won't lock.

[contact_points]
static_pitch=10.492
static_cg_height=7.002
tailwheel_lock =1
max_number_of_points=9
point.0=1, -18.9741, 0, -3.4349, 2200.102, 0, 0.639, 70, 0.4, 2.6, 1.019, 0, 0, 0, 0, 0
point.1=1, 1.833, -4.9169, -7.6409, 1800.803, 1, 1.5, 0, 0.8, 2.5, 0.563, 0, 0, 2, 0, 0
point.2=1, 1.833, 4.917, -7.6409, 1800.803, 2, 1.5, 0, 0.8, 2.5, 0.563, 0, 0, 3, 0, 0
point.3=2, 0, -26.2606, 3.5335, 2500.803, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.4=2, 0, 26.2606, 3.5335, 2500.803, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.5=2.000, -22.333, 0.000, -1.333, 2500.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 9.000, 0.000, 0.000
point.6=2.000, 9.917, 0.000, -3.667, 2500.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 4.000, 0.000, 0.000
point.7=2.000, -16.333, 0.000, 6.833, 2500.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 7.000, 0.000, 0.000
point.8=2.000, -1.000, 0.000, -1.833, 2500.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 8.000, 0.000, 0.000


Do I have any other recourse to get it to work besides this? The plane in question is B. Gladden's Norseman which in real life did allow the wheel to be locked. Some models work just by adding this line others don't. Maybe something in the airfile?

Thanks-

[hairyspin]

AirWrench has a tick box on the Systems tab to make a tailwheel lock available. :gossip:

My limited experience with Airwrench suggests that if a setting can be done in aircraft.cfg without affecting the FM, it won't be found in AirWrench. Prop rotation being a case in point.

[Milton Shupe]

Try putting the statement in the Flaps section where the SDK defines it. That might help, not sure.

[Moses03]

No joy putting it in the flaps section.

Ticking off that box in Airwrench just adds the entry to the contact points section correct?

[fliger747]

Moz:

Looks to me like you have a 70 deg steerable tailwheel. I think if you make the 70 figure 180 (castoring) then it will lock with such key strokes as {Shift - G} or a button on the stick or whatever you assign. I think that the steerable TW function overides the ability to lock (unless they changed this).

Let me know if you find another functionality!

Cheers: T.

[Bradburger]

Try putting the statement in the Flaps section where the SDK defines it. That might help, not sure.

Milton,

I think that's a mistake in the FS2004 SDK!

IIRC, the the FS2002 SDK has it located in the Contact Points section, as in Moses03's example.

Below is an example from my FM for the WoP P-51D, where the tailwheel lock (should really be steering of course!) works with no problems: -

[contact_points]
max_number_of_points = 13
point.0 = 1, -13.76, 0, -3.401, 2650, 0, 0.55, 180, 0.2, 2.5, 0.85, 2.2, 1.8, 0, 220, 202.4
point.1 = 1, 1.5, -5.45, -7.181, 1650, 1, 1.168, 0, 0.5, 2.5, 0.85, 6.9, 4.6, 2, 220, 202.4
point.2 = 1, 1.5, 5.45, -7.181, 1650, 2, 1.168, 0, 0.5, 2.5, 0.85, 5.6, 3.8, 3, 220, 202.4
point.3 = 2, -0.5794, -18.517, -0.879, 3000, 0, 0, 0, 0, 0, 0, 0, 0, 5
point.4 = 2, -1.35, -17.5841, -1.5, 2200, 0, 0, 0, 0, 0, 0, 0, 0, 8
point.5 = 2, -0.5794, 18.517, -0.879, 3000, 0, 0, 0, 0, 0, 0, 0, 0, 6
point.6 = 2, -1.35, 17.5841, -1.5, 2200, 0, 0, 0, 0, 0, 0, 0, 0, 7
point.7 = 2, -16.4094, 0, -1.7409, 4500, 0, 0, 0, 0, 0, 0, 0, 0, 4
point.8 = 2, -20.328, 0, 0.2231, 2000, 0, 0, 0, 0, 0, 0, 0, 0, 9
point.9 = 2, -4.8201, 0, -4.1291, 3200, 0, 0, 0, 0, 0, 0, 0, 0, 4
point.10 = 2, 10.643, 0, 0, 4500, 0, 0, 0, 0, 0, 0, 0, 0, 4
point.11 = 2, 5.4799, 0, -2.7323, 2700, 0, 0, 0, 0, 0, 0, 0, 0, 4
point.12 = 2, 8.926, 0, -2.9198, 2000, 0, 0, 0, 0, 0, 0, 0, 0, 7

static_pitch= 11.776
static_cg_height= 6.071
gear_system_type = 1
tailwheel_lock = 1

Studying the CP entries Moses03 has posted, it would seem that Tom is correct about the 70 degree steering angle.

I'm sure if you change it to 180 (I'm sure Tom is correct about a steerable tailwheel disabling the lock), and make sure you have a key defined to turn it on or off in FS (Shift+G in my case), all should be fine!

Cheers

Paul

[Moses03]

I changed the entry to 180 but it didn't lock. Maybe it's something built in with the model that prevents it from working.

Thanks for your suggestions anyways.

[Milton Shupe]

Moses, is it likely that he used rudder steering? IOW, if you changed the contact point 0 from 70 degrees deflection to 180 but it did not castor, then he used the rudder tag to do the steering. In that case, there is no tailwheel to un/lock ... it is a rudder instead.

Bradburger, good point. I was referencing the FS2004 SDK but it is likely wrong as well. I have the tailwheel_lock = parameter in different places on different aircraft I noticed. I suspect as long as it appears after the correct section that it will work.

[Bradburger]

Moses, is it likely that he used rudder steering? IOW, if you changed the contact point 0 from 70 degrees deflection to 180 but it did not castor, then he used the rudder tag to do the steering. In that case, there is no tailwheel to un/lock ... it is a rudder instead.

Bradburger, good point. I was referencing the FS2004 SDK but it is likely wrong as well. I have the tailwheel_lock = parameter in different places on different aircraft I noticed. I suspect as long as it appears after the correct section that it will work.

Milton,

You know, I don't recall ever checking to see if the tailwheel_lock entry worked anywhere else other than under the contact points section, but from what you've said, I guess it might not matter! (I was always a bit puzzled by the FS2004 SDK having it moved to the FLAPS section). I know Sparks has followed the FS2004 SDK, and has it under the Flaps section in the current FDWB, although I think in AW, it's back under the contact points section.

And an interesting point about the rudder tag animation.

The thing is, I've added fully castoring tailwheels to the Aircraft CFG on MDL's that have the tailwheel animation move with the rudder (which I assume to be the rudder tag, but I could be wrong!) and still get the FM behaviour of a fully castoring tailwheel, although of course the animation only moves with the rudder!

Not being a modeller, exactly how many animation tags for tailwheel animations are there? I know there's the one which will animate it as steerable or fully castoring, depending if you define it as either one in the Aircraft CFG, and the rudder tag one you mention, but are there anymore?

If so, do they overide a fully castoring tailwheel that's been set in the Aircraft CFG file?

Cheers

Paul

[Bradburger]

OK, I've downloaded Brian's Norseman, norseman_v2.zip which I assume is the aircraft you are using.

I checked the Aircraft CFG, and the tailwheel was indeed set to steerable (70 degrees). So I changed it to fully castoring (180 Degrees), and added the tailwheel_lock = 1 entry under the Contact Points section. (I did a quick check of the CP's against the visual model in ACM, and whilst they could probably do with some tweaking, they were generally in the right place).

Now, initally I got the impression that the tailwheel lock was not working, as Moses03 had found, but a little more investigation showed that it actually was, albeit not as one would expect!

The problem was that there was too much prop blast on the rudder in the airfile, and this was meaning, despite the tailwheel being locked, that the rudder power was such that it made no real difference if it was locked or not! (Note my comments about not having a natural tendency to swing below also).

Therefore, I opened up the airfile in Aircraft Airfile Manager (AAM), and adjusted the prop blast on the rudder Cn_dT Yaw Moment -Thrust in the Primary Aerodynamics section (Rudder Control Due To Propwash in the FDWB) from 0.055 to 0.00425, and this now means that the rudder power from the propwash is much lower, and the tailwheel now feels more like it's locked.

However, with the tailwheel unlocked, there is no real tendency for it to swing or ground loop as you might expect, given that the real aircraft has a tailwheel lock (they don't normally fit them for show!), and I think maybe a new FM with correctly set up dimesions, CoG etc. (a good project for someone new to Air Wrench perhaps!), might be the best answer for more realistic ground handling, and of course improved flight dynamics.

Cheers

Paul

[Moses03]

Paul- Thanks for taking the time to look into the airfile. I see what you mean about the wheel feeling a little like it is locked having reduced the propwash. Like you said it does not want to groundloop readily so I can manage for now.

Moses