Tail wheel behaviour

[ilikepie]

just trying to get my head around the tail wheel behavior. Read in a few check lists that you should "taxi forward a few feet to straighten the tail" which makes sense, and have experimented/tried it a few times, coming to a full stop in a turn, then powering up again to see if the the AC travels straight.

 

When power is reapplied the AC continues in the turn that it was in and doesn't "straighten after a few feet"

 

the only way i can get it the AC on a straight path is to apply opposite rudder / brake to the yaw movement till its on an even keel.

 

Am i crazy or just doing something wrong? (first part is rhetorical) 

[razo+r]

Seems you just misinterpreted the instructions. You have to use brakes to straighten the tailwheel when you stop directly after a turn. It will not center itself. 

[Nealius]

10 minutes ago, razo+r said:

Seems you just misinterpreted the instructions. You have to use brakes to straighten the tailwheel when you stop directly after a turn. It will not center itself. 

 

As in, brakes held with rudder while applying power? While stationary?

 

I've been having the same problem. I use the brakes to straighten her out, roll forward a bit, then as I apply brakes with pedals neutral she will tilt off to one side during the stop, causing misalignment on takeoff.

Edited October 1, 2021 by Nealius

[Basco1]

You've got to taxi forward to straighten the tailwheel,but then hold the stick back to keep it locked,if taking off once you've reached about 34 Mph then bring the stick forward slightly before giving it the full beans 3000 RPM required for take off and bringing the stick to the neutral position.

[razo+r]

6 minutes ago, Nealius said:

 

As in, brakes held with rudder while applying power? While stationary?

 

I've been having the same problem. I use the brakes to straighten her out, roll forward a bit, then as I apply brakes with pedals neutral she will tilt off to one side during the stop, causing misalignment on takeoff.

 

As in, you align with the runway and instead of directly stopping, you keep rolling a bit to make sure the tailwheel is straight. 

7 minutes ago, Basco1 said:

You've got to taxi forward to straighten the tailwheel,but then hold the stick back to keep it locked,if taking off once you've reached about 34 Mph then bring the stick forward slightly before giving it the full beans 3000 RPM required for take off and bringing the stick to the neutral position.

There is no tailwheel lock. 

[Nealius]

19 minutes ago, razo+r said:

As in, you align with the runway and instead of directly stopping, you keep rolling a bit to make sure the tailwheel is straight. 

 

I do that, but as I stop she will always veer off to one side or another despite rudders neutral while braking. This is after rolling straight for some 10m before stopping.

Edited October 1, 2021 by Nealius

[Sarge55]

Try using the W key rather than your pedals after straightening it out. It should apply a perfectly neutral braking. See if the same side shift occurs. If it stops straight then you know the pedals are the issue. 

[grafspee]

So correct with rudder while coming to stop.

[Basco1]

59 minutes ago, razo+r said:

 

There is no tailwheel lock. 

Sorry...Yes correct...there is no tailwheel lock,I got that totally wrong.....so there is no requirement to hold the stick back at all.....thanks for the correction razo+r 

[ilikepie]

Probably me misinterpreting what has been written,

 

but to use the analogy of pushing or pulling a three wheeled pram (front wheel is free castoring), you can stop it with the wheel in a turn position but when you apply equal force   (push/pull) the wheel itself is pulled straight by the friction and weight and the pram moves in straight line rather than holding the turn.

 

for some reason, this is the logic my brain is expecting after executing a full stop and then reapplying thrust. hence the boggle

Edited October 1, 2021 by ilikepie

[Nealius]

1 hour ago, grafspee said:

So correct with rudder while coming to stop.

 

That's the thing: it won't. I'm giving my pedals the absolute minimum deflection physically possible and it's always overcorrecting. With a 20 curve......

[ilikepie]

Nealius, is that with full brake pressure? i saw some keybinds that were for increase decrease brake pressure and have found that using different amounts of brake pedal deflection  has an influence, if that makes sense?

Edited October 1, 2021 by ilikepie

[grafspee]

I saw ppl complain that brakes in mossie while using key, are applied too fast, not like in the spitfire that you can maintain low braking force by tapping.

[Nealius]

1 hour ago, ilikepie said:

Nealius, is that with full brake pressure? i saw some keybinds that were for increase decrease brake pressure and have found that using different amounts of brake pedal deflection  has an influence, if that makes sense?

 

 

This is with a toe brake axis. I think the brake axis itself is fine, but something's not right with Saitek Pro pedals. They often require millimeter precision that my feet are incapable of making.

[razo+r]

25 minutes ago, Nealius said:

 

This is with a toe brake axis. I think the brake axis itself is fine, but something's not right with Saitek Pro pedals. They often require millimeter precision that my feet are incapable of making.

 

I recommend you not to use a foot pedal for something operated by the hand in the first place. Rather use a key/button than the foot for this. 

[Nealius]

3 minutes ago, razo+r said:

 

I recommend you not to use a foot pedal for something operated by the hand in the first place. Rather use a key/button than the foot for this. 

 

Key/button is either 0% off or 100% on with no gradient, and thus mostly unusable. Same for the Spitfire and all the Russian aircraft. When I switched from key/button to axis my taxi and braking become much more controllable. The only exception is with the Mossie's takeoff lineup. The brake axis is irrelevant anyway, as I said the problem lies in the rudder axis. 

Edited October 1, 2021 by Nealius

[ilikepie]

tried more curve on the rudder axis? i think set mine at something like 30

Edited October 1, 2021 by ilikepie

[Nealius]

24 minutes ago, ilikepie said:

tried more curve on the rudder axis? i think set mine at something like 30

 

 

Currently at 20 but I can try higher. I don't think I've ever gone higher than 20 on any module, though the Mossie's rudder seems much more effective than other aircraft we have.

Edited October 1, 2021 by Nealius

[Art-J]

4 hours ago, Nealius said:

 

Key/button is either 0% off or 100% on with no gradient, and thus mostly unusable. 

 

Nah, it's not that bad - there is an artificial linear gradient implemented, sufficient enough to taxi quite smoothly in the Spit just by tapping the brake key/button shorter or longer.

 

It doesn't work very well in Mossie, though, where brake force "fills up" almost immediately, so it's indeed much more difficult to modulate by tapping. Eh... Lack of consistency across ED modules in how the same system is implemented gets on my nerves sometimes ;).

[Nealius]

It led to a lot of problems for me in the Spit. Very hard to taxi on curved taxiways, frequently tipping on my nose, etc. Once I switched to toe brake axis it was so much easier to maneuver and stop without tipping, and for some reason doesn't exhibit quite the same behavior as the Mossie when trying to straighten the tailwheel. In the Mossie it feels like the braking system "remembers" which pedal I previously pressed. So if I apply brakes to the left, then neutralize the pedals, apply brakes again, it's like the brakes get re-applied to the left instead of going to both wheels equally.

[Art-J]

You might be on to something. I often find it a bit tricky to stop all straight and in line with the runway, doing way too many minor corrections (and overcorrections  ) than in the Spit. I always though it might be a side effect of me not applying exactly the same power on both sides with my split throttles (about 50 RPM difference you mentioned in the other thread). Will have to do some taxiing tests with external cam to see what actually happens there.

[Nealius]

The assymetric thrust you mentioned is a good point. I'm not particularly paying attention to my throttle but I typically keep them at 1100~1200 all throughout taxi. I'll try cutting to idle before I stop and see if she straightens out a bit.