cub footwork on rudder

[thewoo1]

any guys that have flown the cub ..how are the rudder controls, they are different it looks like heel brake as opposed to toe..just noticed..looks a bit difficult

[DHenriques_]

any guys that have flown the cub ..how are the rudder controls, they are different it looks like heel brake as opposed to toe..just noticed..looks a bit difficult

I instructed in J3's. Yes, it has small heel brake pedals along side the rudder pedals and using them properly can be an "interesting" process. Basically you only really need brakes on the Cub for engine checks and tight turns that shouldn't have been necessary had you planned right while you were taxiing. )
This being said I would add that brakes are a last resort on any landing in a J3.
Using the brakes is a foot juggling affair where you end up with half your foot on the rudder pedal and your heel half on the brake.
It's great fun actually and once you get the hang of it not all that bad.
Dudley Henriques

[thewoo1]

thanks for your perspective and btw your real time p51 start article was great..ty

[DHenriques_]

thanks for your perspective and btw your real time p51 start article was great..ty

Your welcome. Thank you. Glad you enjoyed the piece.
DH

[Dooga]

any guys that have flown the cub ..how are the rudder controls, they are different it looks like heel brake as opposed to toe..just noticed..looks a bit difficult

I instructed in J3's. Yes, it has small heel brake pedals along side the rudder pedals and using them properly can be an "interesting" process. Basically you only really need brakes on the Cub for engine checks and tight turns that shouldn't have been necessary had you planned right while you were taxiing. )
This being said I would add that brakes are a last resort on any landing in a J3.
Using the brakes is a foot juggling affair where you end up with half your foot on the rudder pedal and your heel half on the brake.
It's great fun actually and once you get the hang of it not all that bad.
Dudley Henriques

Dudley, good to hear you chime in on this topic - can I get your opinion (and the general feasibility) of something related to the Cub's rudder pedals as well?
The point: I've not flown a J3 yet, but a PA-18 - and one thing is certainly very different in the real plane, compared to FSX: I could never rest my feet during landing and just watch the plane roll straight!
After I experienced taildragger handling in real life I was a bit disappointed that even the A2A Cub didn't replicate that - so my question: I assume the Cub also needs lively feet on the ground - is there any statement on why this isn't implemented in the A2A version? Is it straight out impossible to change ground handling in FSX, or is there another reason?

Thanks,
Daniel

[DHenriques_]

any guys that have flown the cub ..how are the rudder controls, they are different it looks like heel brake as opposed to toe..just noticed..looks a bit difficult

I instructed in J3's. Yes, it has small heel brake pedals along side the rudder pedals and using them properly can be an "interesting" process. Basically you only really need brakes on the Cub for engine checks and tight turns that shouldn't have been necessary had you planned right while you were taxiing. )
This being said I would add that brakes are a last resort on any landing in a J3.
Using the brakes is a foot juggling affair where you end up with half your foot on the rudder pedal and your heel half on the brake.
It's great fun actually and once you get the hang of it not all that bad.
Dudley Henriques

Dudley, good to hear you chime in on this topic - can I get your opinion (and the general feasibility) of something related to the Cub's rudder pedals as well?
The point: I've not flown a J3 yet, but a PA-18 - and one thing is certainly very different in the real plane, compared to FSX: I could never rest my feet during landing and just watch the plane roll straight!
After I experienced taildragger handling in real life I was a bit disappointed that even the A2A Cub didn't replicate that - so my question: I assume the Cub also needs lively feet on the ground - is there any statement on why this isn't implemented in the A2A version? Is it straight out impossible to change ground handling in FSX, or is there another reason?

Thanks,
Daniel

The wind setup in FSX does leave a bit to be desired really. What's missing are the small gusts and instant random wind changes you usually have landing the real airplane. In the real world situation the wind is always in motion and you are dealing with that constantly as you land the airplane.

Have you tried setting up a crosswind situation for the Cub in FSX ? What you are describing sounds very much like you might be flying in a no wind or wind down the runway condition? The J3 lands at such a low speed there really isn't much to deal with rudder wise unless in a crosswind environment even in the real Cub.
Try setting up for some medium strength crosswind in FSX. That might make the landings a bit more "challenging" as they say )
DH

[Dooga]

The wind setup in FSX does leave a bit to be desired really. What's missing are the small gusts and instant random wind changes you usually have landing the real airplane. In the real world situation the wind is always in motion and you are dealing with that constantly as you land the airplane.

Have you tried setting up a crosswind situation for the Cub in FSX ? What you are describing sounds very much like you might be flying in a no wind or wind down the runway condition? The J3 lands at such a low speed there really isn't much to deal with rudder wise unless in a crosswind environment even in the real Cub.
Try setting up for some medium strength crosswind in FSX. That might make the landings a bit more "challenging" as they say )
DH

Hi Dudley, thanks for the reply - what I'm on about is not about wind, though. It's about the fact that with a taildragger, the center of mass of a plane is behind the (main) wheels running on the ground, which means that as soon as the direction the main wheels are running in becomes slightly different from the direction the mass wants to go, it will turn the plane around rather quickly (ground loop) - which is why you're constantly dancing on the pedals to keep the plane straight after touchdown, even without wind. Once the direction the wheels are rolling in diverges from the direction the mass wants to go, it escalates rather quickly when not corrected, the system is dynamically unstable.

This is the reason why the tricycle gears were marketed as land-of-matics fifty years ago, wasn't it? In the case of a tricycle gear, the center of mass is ahead of the main wheels, which means after touching down the mains the center of mass will just pull the wheels after it, any directional deviations are self-corrected (dynamically stable).

There's also the fact that touching down a tri gear will tend to lower the AoA on touchdown as the noes goes down a bit, eliminating the hopping tendency of a improperly touched down taildragger, as the AoA increases there momentarily as the tail goes down a bit once the mains are touching the ground, but that's not what I'm missing in FSX. I'm missing the instability around the yaw axis.

Cheers!


P.S.: I just thought of a simile to what I'm talking about: take a wheelbarrow, and push that ahead of you, not correcting for direction deviations - after a couple of steps it will deviate to one side or other, you'll walk by it (switching hands in the process...) and then will be pulling it after you. You groundlooped the wheelbarrow, and now it's dynamically stable, being pulled by you (the center of mass just going straight).

[Oracle427]

I find that you nailed this right on the head with your description. The system feels dynamically stable when it actually should be dynamically unstable. It handles like a nose wheel instead of a tail wheel.

I found the default J3 to be unstable though way too unstable with respect to the real aircraft. Not sure if it would be possible to assume a balance between the two.

[Dooga]

I find that you nailed this right on the head with your description. The system feels dynamically stable when it actually should be dynamically unstable. It handles like a nose wheel instead of a tail wheel.

I found the default J3 to be unstable though way too unstable with respect to the real aircraft. Not sure if it would be possible to assume a balance between the two.

Are you sure the default J3 models this? I'll try later, but I don't believe it. I've never ever found a realistically handling taildragger in FSX, point in case: not even the high-end and extremely well done A2A Cub does this right.
The only sim where I've experienced the real taildragger-landing-beads-of-sweat-on-the-brow feeling is IL-2: Sturkmovik BoS from 1C Studios, especially with the LaGG-3 they modelled as their first plane. That one is a handful, brilliantly done - and a lot more stressful than the real life Super Cub I've gotten my tailwheel checkout in, as in case of the Lavochkin we're talking a really heavy plane with a lot higher speeds on landing... and they still didn't model the tailwheel lock

[Oracle427]

The default J3 and P51will quickly get away from you and ground loop if not checked right away. In the J3 it is way too aggressive and results in the airplane flipping onto it's side even at low airspeeds if the tail gets a few degrees to one side. It's been a long time since I flew the default but that is my recollection of it.

I don't know squat about the real P51 but I found the default one models the ground handling of a real Stearman close enough for me. You have to dance on the pedals anyone you roll on the ground to keep it lined up.

[Dooga]

Hm you're right, the default Cub actually requires a bit of rudder input to stay straight. But still not nearly as much as I remember from the PA-18, which was a bit faster and heavier, but then again not that much...
Doesn't feel right, but at least it's not as complacent as I thought it was - hail to the default planes

[AndiK]

I completely agree with this assessment, having flown taildraggers in real life I can attest to the work DEFINITELY not being done once the wheels are on the ground, that's when it just starts getting interesting to be honest.

While the A2A J3 does very accurately handle things like forward slips and side slips and so on - nothing wrong with the flight model, I've never had a 'moment' in one once it's on the ground, it seems to settle down nicely.

This of course is a common problem with FSX aircraft which all land a little too 'kindly'. In real life a ten degree heading difference between you and a paved runway might send you into the bushes courtesy of a tire being wrought off its rim, in FSX the plane settles down really nicely. And the ground loop tendencies where you're dancing on the rudder pedals constantly aren't there at all, I can take my hands off the controls once she's on the ground and I'll be fine 90% of the time. In a real Cub that would be a recipe for disaster.

So, if the J3 was up for an update, that is the one thing I'd fix about it...

[DHenriques_]

The wind setup in FSX does leave a bit to be desired really. What's missing are the small gusts and instant random wind changes you usually have landing the real airplane. In the real world situation the wind is always in motion and you are dealing with that constantly as you land the airplane.

Have you tried setting up a crosswind situation for the Cub in FSX ? What you are describing sounds very much like you might be flying in a no wind or wind down the runway condition? The J3 lands at such a low speed there really isn't much to deal with rudder wise unless in a crosswind environment even in the real Cub.
Try setting up for some medium strength crosswind in FSX. That might make the landings a bit more "challenging" as they say )
DH

Hi Dudley, thanks for the reply - what I'm on about is not about wind, though. It's about the fact that with a taildragger, the center of mass of a plane is behind the (main) wheels running on the ground, which means that as soon as the direction the main wheels are running in becomes slightly different from the direction the mass wants to go, it will turn the plane around rather quickly (ground loop) - which is why you're constantly dancing on the pedals to keep the plane straight after touchdown, even without wind. Once the direction the wheels are rolling in diverges from the direction the mass wants to go, it escalates rather quickly when not corrected, the system is dynamically unstable.

This is the reason why the tricycle gears were marketed as land-of-matics fifty years ago, wasn't it? In the case of a tricycle gear, the center of mass is ahead of the main wheels, which means after touching down the mains the center of mass will just pull the wheels after it, any directional deviations are self-corrected (dynamically stable).

There's also the fact that touching down a tri gear will tend to lower the AoA on touchdown as the noes goes down a bit, eliminating the hopping tendency of a improperly touched down taildragger, as the AoA increases there momentarily as the tail goes down a bit once the mains are touching the ground, but that's not what I'm missing in FSX. I'm missing the instability around the yaw axis.

Cheers!


P.S.: I just thought of a simile to what I'm talking about: take a wheelbarrow, and push that ahead of you, not correcting for direction deviations - after a couple of steps it will deviate to one side or other, you'll walk by it (switching hands in the process...) and then will be pulling it after you. You ground looped the wheelbarrow, and now it's dynamically stable, being pulled by you (the center of mass just going straight).

Your tail wheel physics are accurate. I would add a bit more to the tail wheel landing equation such as a momentum issue downward for the cg aft of the main gear at touchdown causing an increase in angle of attack as just one more item for consideration if seeking totally accurate physics in the FSX FDE for a tail wheel aircraft. Of course that's a pitch issue and I see you are concerned with the yaw issue basically.
What I'm getting at here is that the actual physics involved in landing the real tail wheel airplane are extremely complex and unique to the type. For FSX you only have so much code you can write before you cross that magic line where the end user starts to experience degradation in computer performance and the complaints start pouring in about frame rate etc.
I'm not saying it can't be done, but I am saying the developer has to pick and choose carefully where to put assets in the finished program. In the case of tail wheel behavior after touchdown, you have potential divergence in pitch, bank, and yaw all working through a multiple body axis, inertial axis AND a flight axis system all at the same time. Add to this that response effect to any yaw excursion is more leaned toward an exponential curve than a straight proportional response and you have the makings for a LOT of additional code in the flight model. Keep in mind this doesn't even address the added issues involved at touchdown with a lowering cg momentum causing potential bounce due to increasing angle of attack and you can see how terribly complex this can become when considering tail wheel landing physics )
Personally I'd love to be able to see totally accurate replication of issues like the divergence vs response issues you are discussing here but looking at the entire picture as A2A has to look at it I'm understanding of what's involved and how hard it is for the design team to make the necessary decisions involved with packaging a finished FDE.
Perhaps someday we'll have all of this as computer hardware keeps opening new doors for flight model development. I can tell you from personal experience that A2A is working every day on ways to work within and outside the simulator base codes to produce new and better effect accuracy.
So hang in with us. As they say........"We're work'in on it ! "
Dudley Henriques

[Dooga]

Dudley, thanks for the statement - getting across what I'm after was half of the intent of my posts

Agree that modelling ground handling excessively might get out of hand at some point. Still, a first approximation... A2A would definitely be the first and only plane creators that implement realistic ground handling in FSX. Especially relevant as all beautiful/interesting/desirable planes usually are taildraggers

[DHenriques_]

Dudley, thanks for the statement - getting across what I'm after was half of the intent of my posts

Agree that modelling ground handling excessively might get out of hand at some point. Still, a first approximation... A2A would definitely be the first and only plane creators that implement realistic ground handling in FSX. Especially relevant as all beautiful/interesting/desirable planes usually are taildraggers

I forgot to mention that even after we solve everything for the airplane we then have to deal with the surface on which the landing is taking place...i.e friction factors. There is a partial "fix" available that addresses that issue through FSUIPC and an entry into the FSX cfg file but even that doesn't solve it completely. This has driven me absolutely nuts for years dealing with it with FDE development. )))))
DH