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Pulling to the Right on TakeOff Roll Out


Weegie

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Follwing up on the takeoff thread

 

It's been a while since I flew the 109 and I'm guessing that it's the new tyre physics that's to blame.

 

On the rollout at takeoff it pulls hard to the right then engine torque takes over and it's hard to the left. A large brake input to the left on the rollout will send it careering off from right to left.

 

As I've hardly ever flown as a pilot and obviously never a warbird I cannot say if this is realistic, however it seems wrong to me. I find I have to trail the brakes to keep it straight up to around 100 kph, that just seems wrong. A brake input on rollout start of a take off run yes, but up to these speeds?

 

The landings are equally as bad now trying to keep it straight

 

My point is I've also been flying the Dora and Spit and these don't seem to be affected at all (or very little), if, it is the new physics that are to blame. This bird makes the Spit look like a walk in the park to takeoff and land

 

If my car behaved like this I'd be getting the tracking seen to :music_whistling:

 

I'm just baffled as it why it appears to have this pull to the one side, it's not engine torque so it must be something gear related.

 

I'm full nose down trim, manual prop pitch at 12 O'Clock, takeoff assistance is 0 and Auto rudder is disabled

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You're good with the T/O setup, just check the tail wheel to be locked. You can take off without it being locked, some pilots prefer it that way, but I wouldn't recommend it unless you're really accustomed to it.

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Yep, with the general new-physics reduction of lateral tyre grip, tailwheel lock effectiveness is a fraction of what it used to be and that indeed seems to be the culprit of the issue discussed here.

 

On one hand, maybe the lock was too good before - every idiot could takeoff and land the 109 blindfolded as long as he used the lock and kept the stick pulled while the wheels were rolling on the ground. On the other hand, perhaps ED went later too far in the other direction with the new "butter-tyres"...

 

In either case, for me the best way to deal with takeoffs nowadays is slow and smooth throttle operation and using mild power settings. If I throttle up slowly, letting the airplane accelerate somewhat to get a bit of an airflow over the stab, and then go up to 1.35-1.4 ATA of boost, I hardly have to use the right brake, maybe one short dab or two. And that's with auto-mode (which loads the prop heavily and thus increases adverse prop effects). In manual mode at 12:30 it's even easier, I don't have to use the brakes at all.

 

On landings I just throttle down smoothly instead of cutting it, pay closer attention to being lined up as straight as possible and do more rudder dance after touchdown.

 

Crosswinds are obviosuly different matter, but I struggle with them no matter what plane i fly ;).

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

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Trim Stab 0.5-1 foward, put your Flaps on 20 Degrees, will shift the COG Foward, and you will Take-Off absolute smooth even with full Power..

Once you have tasted Flight, you will forever walk the Earth with your Eyes turned Skyward.

 

[sIGPIC][/sIGPIC]

9./JG27

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I have flown the Bf-109 for a long time, and I do not see the take-off behaviour changed. I begin the take-off run with tailwheel locked, full right rudder, max. nose-down trim, flaps about 20% out, full power, engine governor ON.

 

Shortly after she starts rolling, I have to reduce rudder input to keep her straight, and I never use the wheel brakes during take-off.

I have a mod that allows me to use the original flight model, and I have tried with and without the mod, but for me it makes no difference in the take-off run.

LeCuvier

Windows 10 Pro 64Bit | i7-4790 CPU |16 GB RAM|SSD System Disk|SSD Gaming Disk| MSI GTX-1080 Gaming 8 GB| Acer XB270HU | TM Warthog HOTAS | VKB Gladiator Pro | MongoosT-50 | MFG Crosswind Pedals | TrackIR 5

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Ok Le Cuvier, perhaps it's me but I am experiencing a definite pull to the right that was not there before, I made some videos of in cockpit footage and there was no initial swing (at least nowhere near as vicious). Could it be that you're original model is still integrating the new tyre physics?

 

Anyway I'm not here to argue with anybody real or imagined it's what my mind is telling me.

 

Art-J I wasn't pulling back on the stick and using your recommended method has helped a lot. Perhaps one or 2 dabs of the brakes with the prop at 12:30 and a more gradual opening of the throttle is definately the way to go, Thank You

 

Mad-MM I'll certainlly give that a shot sounds interesting, thanks

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...Could it be that you're original model is still integrating the new tyre physics?...

The changed "tyre physics" is just friction coefficients. As both tyres have the same friction value, that factor cannot create a pull to the right. If I didn't give rudder right input I would veer to the left, badly.

LeCuvier

Windows 10 Pro 64Bit | i7-4790 CPU |16 GB RAM|SSD System Disk|SSD Gaming Disk| MSI GTX-1080 Gaming 8 GB| Acer XB270HU | TM Warthog HOTAS | VKB Gladiator Pro | MongoosT-50 | MFG Crosswind Pedals | TrackIR 5

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If I understand what you call "rollout" I guess what you're experiencing is just the usual tyres P factor as you push the stick forward, maybe that? If you push the stick instead of awaiting it to raise the tail by itself you get a "negative" torque effect, even harder due to the short wheels' legs wide. It's quite usual and happens in every taildragger just depending on how much and how soon you push the stick.

 

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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Trim Stab 0.5-1 foward, put your Flaps on 20 Degrees, will shift the COG Foward..

Don't know what makes you think flaps position and/or trim would will alter the CG, but it definitely doesn't.

i7-7700K 4.2GHz, 16GB, GTX 1070 

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Don't know what makes you think flaps position and/or trim would will alter the CG, but it definitely doesn't.

 

It will because pilot have to lean forward to adjust trim or flaps.

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I'm going to experiment some more and see how I get on

 

I'll see if I can make a short clip to demonstrate what I was referring to, it was more of a pull to the right at low throttle openings which (percieved or imagined) wasn't present before.

 

Using Art J's methodology helps a lot and keeping the stick back seems to help alleviate it.

 

Ala13 Before I was keeping stick neutral and not using it all until I lifted, now I have stick back and move it to neutral smoothly around 120kph, but I wasn't clear about what I was referring to

 

Maybe I'm just a basket and need to go back to EF 2000 (for those of you old enough to remember that)

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Well TBH Mabe LeCuvier was correct I'm now not so sure

 

Anyway the issue is now solved, in so much as using Art J's methodolgy I've much improved, although I find it still quite a challenge to remain straight and not balloon

 

Many thanks to all for helping me, especially Art J and LeCuvier for setting me on the road to redemption

 

To add I think the problem I was having is related to the tyre physics I just didn't know it.

 

With the tyres now having a lot less grip I just wasn't ready for how even engine torque at low RPM and the pronounced effects of rudder input would have, leading me to over controlling the aircraft on takeOff


Edited by Weegie
Expanded explantion
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There are various ways to take off this thing - some use auto prop, some manual, some add a bit of flaps, some don't, some use 1 degree of trim, some 2, etc. It's all very subjective and I'm not claiming my method is optimal. Can't really call it "my" anyway, as it seems to be the same way folks operate restored 109 Gustavs in RL.

 

That being said, with reduced tyre grip the plane is indeed more b..tchy to control on the ground and requires more focus and precision nowadays. Not that I'm complaining - that can be somewhat fun in itself (as in "challenge-fun") and the "tweaked" 109 certainly lives up to its infamous ground handling wartime reputation.

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

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I can tell that it is possible to take off in straight line. Practice is needed.

If you have problem with over controlling plane use side slip indicator it will tell you how much rudder you need exactly, or practice and learn how much rudder you need for certain stages for take off. Im taking off with 10-20 flaps + trim nose down w/o brakes prop at 12 o'clock, 1.4 ATA.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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Thanks to all

 

Finally getting the hang of it, although I think it was Art-J who said that he throttles up gradually. This is my preferred way of doing take offs with the warbirds too but with the 109 it isn't working for me. Now I throttle up on fixed pitch (12:30), no flaps, Trim full down, stick full back and full right rudder. When I reach 2000 RPM I then push up through quickly until 2500. I find if I'm in the 2-2.5k region the aircraft will keep pulling to the left, no matter what.

 

Once at 2.5k the small left swing quickly becomes a right swing and I can control the magnitude with varying right rudder.

 

Stick to neutral at somewhere arounnd 120-150 IAS and a few seconds later I'm up and away.

 

I was also having horrendous swings at touchdown too. Is this because of the small tail? It's just odd (to me) that an aircraft with a marginally wider track and a locked tailwheel appears more unstable (comparing to the Spit)

 

Seem to be getting around this now with 3 pointing and full stick back after a second delay (otherwise she sometimes baloons)

 

Prop pitch to manual at 12:30 has also helped to stabilize the landing, so I'm happy that you guys have helped me understand the changes and modify my old ways for this bird.

 

I'll post up a YouTube Vid when I get the time, the only tutorial with the new physics was a GrimReapers vid and his landing was pretty rubbish.............even by my low standards

 

 

Appreciate all your time

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... I find if I'm in the 2-2.5k region the aircraft will keep pulling to the left, no matter what.

Once at 2.5k the small left swing quickly becomes a right swing and I can control the magnitude with varying right rudder.

I propose a slightly different explanation:

When your speed is below 100 km/h the rudder has little or no effect and the propeller torque pulls you left.

When your speed goes above 100 km/h the rudder has increasingly more effect and you need to move your rudder gradually more to the center position to run straight.

LeCuvier

Windows 10 Pro 64Bit | i7-4790 CPU |16 GB RAM|SSD System Disk|SSD Gaming Disk| MSI GTX-1080 Gaming 8 GB| Acer XB270HU | TM Warthog HOTAS | VKB Gladiator Pro | MongoosT-50 | MFG Crosswind Pedals | TrackIR 5

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I propose a slightly different explanation:

When your speed is below 100 km/h the rudder has little or no effect and the propeller torque pulls you left.

When your speed goes above 100 km/h the rudder has increasingly more effect and you need to move your rudder gradually more to the center position to run straight.

 

I would say that rudder effect starts as soon as power is applied. Prop wash gives some effect on rudder then increasing air speed going in to this with increasing speed, but in case of bf 109 rudder is quite small that is not sufficient to counter left Yaw but once you get some speed things changes.

In sims over controlling is common issue.

I find difficulty in controlling rudder at high speeds when slight movement of rudder swing nose left right with uncontrollable manner.

I find very hard to aim at small ground target in high speed dive when in reality there was no such a problem, I would like to implement some kind of smooth reduction gear for rudder so i can use whole movement of my rudder pedals with reduced movement of plane's rudder.

Right now it looks like that if you gain speed it is simply cutting off you range but gear ratio is still the same.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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  • ED Team
I would say that rudder effect starts as soon as power is applied. Prop wash gives some effect on rudder then increasing air speed going in to this with increasing speed, but in case of bf 109 rudder is quite small that is not sufficient to counter left Yaw but once you get some speed things changes.

In sims over controlling is common issue.

I find difficulty in controlling rudder at high speeds when slight movement of rudder swing nose left right with uncontrollable manner.

I find very hard to aim at small ground target in high speed dive when in reality there was no such a problem, I would like to implement some kind of smooth reduction gear for rudder so i can use whole movement of my rudder pedals with reduced movement of plane's rudder.

Right now it looks like that if you gain speed it is simply cutting off you range but gear ratio is still the same.

 

Rudder is not a good mean to aim, especially with rockets, but with guns as well.

Overcontrolling at TO is a different song. The main problem is not a plastic rudder but absence of acceleration info. That's why it is necessary to train "acceleration feeling" from visual angular velocity. The second mistake I often see is improper understanding of rudder input. There is no compulsory right rudder - you need to apply any rudder - right or left - to avoid plane breaking from the straight line.

If the plane is overcontrolled to right, you need left rudder to stop this movement.

I wrote it many years ago, that if the tail goes up, there are some things that affects the plane: as you have rotational nose-down velocity, gyro moment turns the plane left requiring additional right rudder input. But as the plane starts to roll steady at lower AoA the P-factor is less, so less right rudder is required.

I need to add, that if the tail wheel is locked, the stabilized moment from it disappears as the tail goes up requiring additional right rudder.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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Rudder is not a good mean to aim, especially with rockets, but with guns as well.

Overcontrolling at TO is a different song. The main problem is not a plastic rudder but absence of acceleration info. That's why it is necessary to train "acceleration feeling" from visual angular velocity. The second mistake I often see is improper understanding of rudder input. There is no compulsory right rudder - you need to apply any rudder - right or left - to avoid plane breaking from the straight line.

If the plane is overcontrolled to right, you need left rudder to stop this movement.

I wrote it many years ago, that if the tail goes up, there are some things that affects the plane: as you have rotational nose-down velocity, gyro moment turns the plane left requiring additional right rudder input. But as the plane starts to roll steady at lower AoA the P-factor is less, so less right rudder is required.

I need to add, that if the tail wheel is locked, the stabilized moment from it disappears as the tail goes up requiring additional right rudder.

 

What i heard is that pilots used rudder to aim with guns and rockets, bf 109 for example because long tail had impressive ability to swing nose right or left in order to hit target, which p-51 lacked.

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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What i heard is that pilots used rudder to aim with guns and rockets, bf 109 for example because long tail had impressive ability to swing nose right or left in order to hit target, which p-51 lacked.

In a ground attack run I use the rudder primarily to keep the ball centered and fly a straight line towards the target. If the ball isn't centered it's very hard to hit the target.

LeCuvier

Windows 10 Pro 64Bit | i7-4790 CPU |16 GB RAM|SSD System Disk|SSD Gaming Disk| MSI GTX-1080 Gaming 8 GB| Acer XB270HU | TM Warthog HOTAS | VKB Gladiator Pro | MongoosT-50 | MFG Crosswind Pedals | TrackIR 5

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...There is no compulsory right rudder - you need to apply any rudder - right or left - to avoid plane breaking from the straight line.

If the plane is overcontrolled to right, you need left rudder to stop this movement.

Are you saying that you can perform the take-off run without right rudder input?

LeCuvier

Windows 10 Pro 64Bit | i7-4790 CPU |16 GB RAM|SSD System Disk|SSD Gaming Disk| MSI GTX-1080 Gaming 8 GB| Acer XB270HU | TM Warthog HOTAS | VKB Gladiator Pro | MongoosT-50 | MFG Crosswind Pedals | TrackIR 5

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  • ED Team
What i heard is that pilots used rudder to aim with guns and rockets, bf 109 for example because long tail had impressive ability to swing nose right or left in order to hit target, which p-51 lacked.

 

Rockets - noway, because the rocket having its own stability will get to the plane velocity vector. By the way, what was a ball for at the base of gun sight? ;)

But the nose swing was common for fire spreading.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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  • ED Team
Are you saying that you can perform the take-off run without right rudder input?

 

No, I meant that instant rudder position can be left or right.

 

The average - right for sure.

 

Just to be more clear - take a look at the rudder input at the different power settings.

 

 

Although it is Spitfire, but the same principles are right for Bf-109 as well regarding the power and how to apply it - slow or fast.

 

The rule of thumb:

steerable tail wheel - gradually applied power is the best. Steering power is providing with the tail wheel, and TO power can be aplied a bit later as the speed is enough to add stability to the plane;

locked tail wheel - almost the same but sometimes it needs a bit more power to counteract initial plane instability;

unlocked tail wheel - TO power applied faster to have maximal steering power to counteract plane instability.

 

Bf-109 aggressive tail lift

 

Bf-109 with unlocked tail wheel


Edited by Yo-Yo

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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