Corsairs..?

[SgtPappy]

If these renditions of vintage aircraft flew exactly the way they do in r/l, 90% of you would never get them off the ground.  90% of the remaining 10% would never land one.  IMHO, if these aircraft stalled and spun like they did in r/l, the whole playing style in here would change to one of much more complex flight management and risk assessment.

Does this mean that our various FMs are far and beyond from modeled properly? Do mean this in respect to such factors as combat trim, the lack of a realistic ground/bounce/landing characteristics (and other factors that make the flight model easier to handle for newer players)?

Or do you mean simply that the flight models of the aircraft are completely unrealistic?

Just wondering exactly what you mean.

[Krusty]

Hitler Youth, with minimal glider training, were forced into planes. Sure there were accidents, but most of these greenhorns died because they had no COMBAT training, not because they couldn't take off or land. Got popped by allied guns.

[Krusty]

Care to enlighten us Krusty as to why un-powered, torque-less sailplanes bother with vertical stabilizer and rudder? How about jet aircraft, and the torque-neutralized P-38?

No need to get insulting, by the way. I don't post for a number beside my name.

To answer the (possibly obvious) question: That's why I rephrased it to say "major" purpose.

It's yaw stability. A single engine plane yaws because of the torque. With air moving over the vertical stabilizer, that torque is countered. Even without this torque, you still need yaw stability due to vortexes, airflow, turbulence, what have you. Add torque and it just gets much worse. P.S. The P-38 still has torque, just 2 opposing forces cancel each other out.


For your VF-17 story, that's far from showing ANY stall characteristics. He's fast, on the deck, running, and 4 zeros dive on him. The first starts locking up, so he pops flaps, gear, nose down for an overshoot, and then keeps going. The other zeros kept up with him (from a dive) but did not catch him, so that's not a stall by any sense of the word. He barely slowed down. Just enough to force an overshoot on a plane that was already too fast. Heck I can do that in the MA without popping gear or flaps. A slight jink, and back, and you got a snapshot. You can do that at 450mph. Has nothing to do with stall handling on the corsair.

[Bodhi]

Hitler Youth, with minimal glider training, were forced into planes. Sure there were accidents, but most of these greenhorns died because they had no COMBAT training, not because they couldn't take off or land. Got popped by allied guns.

The had a bit more than just glider training Krusty.  They also died or where horribly injured in droves because they did not know to take off and land. 

[Bodhi]

A single engine plane yaws because of the torque. With air moving over the vertical stabilizer, that torque is countered. Even without this torque, you still need yaw stability due to vortexes, airflow, turbulence, what have you. Add torque and it just gets much worse. P.S. The P-38 still has torque, just 2 opposing forces cancel each other out.

Do you honestly believe that the vertical fin dissipates all the torque by itself just with airflow flowing over it????  Increasing the throttle even at high speed does not increase torque that has to be countered with something other than the vertical fin??? 
By that logic, why not cut the size of the rudder to a 1/4 of it's size as all it is used for is to deal with "airflow turbulence and vortexes"? 

Come on man, research stuff before posting.  You are just plain wrong on this one and are making yourself look silly.

[Krusty]

Bodhi, I'd like to hear your point of view as well.

The way I figure it works, and this is based on basic understanding of airflow, torque, and basic physics, is as such:

The propellor spins one way
The force of the engine on the airframe wants to spin it the opposite way (not just along 1 axis though)

The prop spins left, creating a left vortex over the top of the plane

The plane wants to spin right.

The left-flowing vortex over the top of the plane hits the vertical stabilizer, pushing it left (counteracting the fuselage push to the right).

At higher speeds, also, the air on either side of the vertical stab helps to keep it from rolling either way (creating stability).


Note, however, that even in AH as is modeled now, certain 109s and the typhoon start yawing at full power on auto climb because of the torque. You throttle down and this goes away. You reduce throttle while landing in a ta152 and you get a lot less torque. Same for F4u family. Reducing RPM in a hammerhead reduces the need for more rudder.


Increasing the throttle does increase the torque, but usually it also speeds the plane up, and the increased airflow over the v-stab adds more resistance to roll either way.

I'm not negating ailerons. I'm just saying they're not meant for torque control.

[Bodhi]

Does this mean that our various FMs are far and beyond from modeled properly? Do mean this in respect to such factors as combat trim, the lack of a realistic ground/bounce/landing characteristics (and other factors that make the flight model easier to handle for newer players)?

Or do you mean simply that the flight models of the aircraft are completely unrealistic?

Just wondering exactly what you mean.

Pappy, I think it is about as close as they can get in a game.  It is just not going to be possible to represent all the forces that are in real flight without some sacrifices being made for game play. 

Do you want to introduce violent snap rolls into a spin when you depart coordinated flight in a large number of warbirds?  I really don't want that.  Some fighters lose 6000 feet before they recover in a spin.   That basically means if you stall it (in some aircraft it will spin in regardless of what you do) you are going to spin down atleast that prescribed altitude before the aircraft is in a situation where it can be recovered.  There are major reasons why the Mustang, Corsair, P-47, and most all fighters are Placarded to prohibit intentional spins.

[Bodhi]

Krusty,
When I pull the Corsair out (or any other aircraft for that matter), and I fire it up for a run up or check, I am aware of many things, but for sure two definites.  When I throttle up, I'd best do it slow and even or I am going to be upside down and probably dead or wish I was because the fin and rudder can not counter all the torque being introduced in a very short time.  I also make damn sure the stick is pulled all the way back to prevent the tail flying on it's own and me ruining a $100k propellor and $160k engine.

It is a fundamental understanding that the more the throttle is increased, the more torque the engine and prop will generate.  The more torque generated the more the pilot has to counter this torque.  In flight, the vertical fin on most Warbirds is generally offset a small amount to introduce a certain amount of force in flight to help counter this torque.  I believe (been a long time since we set it) that this offset of the vertical stabilizer on the Corsair is 2.5 degrees off the longitudinal axis.  Even though this offset exists, you still have to counter the force of the torque when you increase the throttle, or not over compensate when you decrease.  To help aid in this, the rudders are generally equipped with trim tabs and boost tabs.  The trim tab allows the pilot to dial in a setting that helps to counter the torque at specific engine settings.  If the pilot increases the throttle, then the torque rises, and they generally dial in more rudder trim to counter act the torque so their legs do not get tired.  Boost tabs do exactly what they sound like.  They allow you to move the control surface even when the airflow forces rise high enough to provide force to counter your movements. 

So in a nutshell, torque is always around, and has to constantly be countered to allow you to fly through the air in coordinated flight.  One last thing, ailerons are for roll control, not turning.  My old instructor got pissed when I used my ailerons and elevators to turn.  The rudder controls the turn.  The ailerons control the roll.

[Krusty]

Would you say the problems when stationary are because there isn't enough airflow over the vertical surfaces yet?

[Bodhi]

No, I'd say it has to do with the 450 plus pound propellor and the engine spinning.  It does not matter if you are in flight either.  You introduce too much torque at once, and you will be corkscrewing through the air.

[mtnman]

If the prop wash pushing against the side of the vertical stabilizer is what counters torque, it would seem redundant to me.  After all, the prop wash can't tell the difference between the vertical and horizontal stabilizers, and there are two horizontal stabilizer surfaces for the prop wash to hit, right?  The top of one, and the bottom of the other?  Wouldn't it make more sense to just enlarge the horizontal stabilizer and do away with the vertical stabilizer?  Yaw stability would suffer drastically of course, but the torque would be countered.  I can see the vertical stabilizer "helping" with torque, but would consider its effect of simply keeping the nose pointed into the slipstream through simple weathervaning as more important by far.

How do aircraft designers know exactly how far forward or back to put the vertical stabilizer so the prop wash can smack into it effectively?  Does the prop wash spiral stay the same "length" at varying speeds and throttle settings?

Does the vertical stabilizer still counter torque when the plane is on its side in flight, or does this duty transfer to the horizontal stabilizer, since it's now vertical?

Birds do just fine without vertical stabilizers, and they obviously don't have any torque (unless one wing is stronger, hehe). Krusty, you said- "Even without this torque, you still need yaw stability due to vortexes, airflow, turbulence, what have you."  Don't birds still experience these phenomena?  Wouldn't they still need a vertical stabilizer to compensate?  I can see when they flap that they could "manually" compensate, but what about while soaring?

MtnMan

[Stoney]

If the prop wash pushing against the side of the vertical stabilizer is what counters torque, it would seem redundant to me...How do aircraft designers know exactly how far forward or back to put the vertical stabilizer so the prop wash can smack into it effectively...Birds still experience these phenomena?
MtnMan

Prop wash against the vertical stabilizer is not what counters torque.  On single engine U.S. fighters in game, it actually increases the overall effect, as propwash against the tail will make the nose yaw left.  There is also a yawing moment from the propellor called "P-effect" or P-factor.  On single engine U.S. fighters in game, P-effect also introduces a left yawing moment.  Torque from the engine contributes to a rolling moment on the aircraft in flight.  Ailerons control roll (or lateral) stability.  The vertical stabs purpose is to control yaw (or directional) stability.  What is important to note is that the yaw input of the rudder introduces roll moments, and roll inputs of the ailerons introduce yaw moments.  That's why you have a ball in the cockpit, and why we have terms like "coordinated turns" meaning that the ailerons and rudders are working in harmony.  The biggest contribution the vertical tail makes to roll stability is in its position--its above the rolling C.G of the aircraft, but its moment arm is much, much shorter than the ailerons in this respect.   

Generally speaking, aircraft designers size and position tail surfaces using equations based on the size of the wing, and the distance between the wing and tail surfaces.  The larger the tail surfaces are, and the further they are from the wing, the more effective they are at controlling yaw (vertical stab) and pitch (horizontal stab).  Stability equations are then performed using the computed centers of gravity.  These are some pretty complex equations. 

As for birds...  Well, the can accomplish almost every aspect of dynamic and static stability through the way they manipulate their wings.  They can increase or decrease span, angle of attack, incidence, area, sweep, dihedral, anhedral, etc.  We haven't figured out a way to do that yet... 

[Patches1]

Just an anecdote...I read either in Baa Baa Black Sheep, or Black Sheep One, that Corsair pilots had over-devloped right thigh muscles due to compensating for engine torque.

[Arlo]

Just an anecdote...I read either in Baa Baa Black Sheep, or Black Sheep One, that Corsair pilots had over-devloped right thigh muscles due to compensating for engine torque.

Which made scrambling for fighters a comical event of having to run "toward" your plane at a right angle to get there? Now that's torque.

[mtnman]

Nice response Stoney-  I was really just being sarcastic, but you put out some good, valid information.  I probably should have refrained from my smart-axx post.

My toss in on the birds was really just to get people to scratch their heads and think "Hmm, birds have no torque, and no vertical stabilizer, so...)  Kind of along the lines of Monty Python's "Search for the Holy Grail's" section on witch identification based on the idea that witches burn, as does wood, and wood floats, as do ducks, so if the gal weighs the same amount as a duck she must therefore be a witch (and of course she does, so she must be a witch...)

I have an inordinate interest and knowledge of birds (I'm a falconer) and am daily in awe of what birds can do in the air.  It's one thing to see one fly by, totally another to see them in active pursuit.  Maybe someday we'll be able to get our aircraft to do 10% of what they can do.  I doubt we'll see it though, at least as far as maneuverability goes.  You can add shifting of CG, and leading edge slats to your list too, before moving on to what they can do with their tails :^)  I fly R/C, and have been on a quest to build a soaring model of a red-tailed hawk or golden eagle, but haven't been able to figure a way to do that without cheating and adding a vertical stabilizer.  The closest I've come is to use drag from wing mounted control surfaces to cause yaw, but I'm not very happy with those results.  I get much better flight control with a vertical stab, but of course my models are much closer to conventional aircraft than to birds, so that should be expected.

MtnMan