Torque effects on takeoff

[jigsaw]

Except, gyroscopic precession affects any plane without a nose wheel during takeoff. So, with most of the planes in AH it kicks in (or should kick in) just as the tail wheel comes up off the ground.

Well....actually...it's a left turning tendency in a conventional gear (tail wheel) and a right turning tendency in a tricycle gear. In the trike it happens at rotation, but because it's "documented" in the AFH with the subnote of "on conventional gear" it's always lumped in with the other lefts.

If you fly some of the Euro/Russkie planes, then torque and P-factor will also be right turning tendencies as the prop rotates in the other direction. I can't recall exactly which ones have the opposite props at the moment, but just as an example, the difference between say an Extra-300 and the SU-29.

[recon1]

I see one person here who has some background in aerodynamics. If ya'll notice on auto take off the ailerons are situated in the right turn position, why???? There is no crosswind on any of these airfields. Ailerons are only in effect when there is airflow. Just as in a stall ailerons are useless until airflow is re-established.

As far as P-Factor and other forces acting upon an aircraft during takeoff, the designers of these aircraft were aware of these forces and built slight airframe designs in order to counteract these forces during takeoff without most importantly taking away the performance during flight. Most fighters during this era used 50% power until airflow was established over the wings and then full power was applied SLOWLY!!!! I know I have taken several rides in a P-51 Mustang and LA-7, for I am a real world pilot and instructor.

Flight modeling is damn good in this game and I dont believe they should make it harder for gamers to takeoff. Not many people understand flight dynamics, resulting in making the game miserable for them if they cannot take off. This should be an option for experienced gamers making the aircraft have increased performance if you know what your doing and less performance for those who choose auto takeoff AGREE???

Just my opinion.

[ccvi]

Originally posted by recon1
As far as P-Factor and other forces acting upon an aircraft during takeoff, the designers of these aircraft were aware of these forces and built slight airframe designs in order to counteract these forces during takeoff

pfactor cannot be compensated. it is purely dynamic, the force acting only when the angular momentum, the attitude of the aircraft changes. No aerodynamic compensation behaves like that. The only way to compensate pfactor is by a mass rotating in the opposite direction of the prop.

[Glasses]

P-factor,Torque, and Spiraling Slipstream on most western WW2 Aircraft had left turning tendencies as the properllor  rotated to the right. In modern tricycle light aircraft they have too left turning tendencies the difference is the severity in which they're manifested.

IMO in AH they seem too light, the 109 for example had very bad habits when being at slow speed if the throttle was  pushed too quickly without having too much speed or while in take -off you could ground loop. The 190 too had a masty snap roll at lo airspeeds and high angle of attack,not just due to the wing loading.

Th 109 had aileron and elevator trim(which moved the whole horizontal stab) it didn't have rudder trim. The 190 did Have elevator trim in the least it was an  electrically driven servo. As far as far as rudder and aileron trim I'm not certain it had these,but anyone much more knowledgeable in the 190's systems might correct me.

[recon1]

I realize p factor is purely dynamic and it is true you would need something counteracting, which is the plane itself. Newton's 3rd Law For Every Action There is an Opposite and Equal Reaction. So the prop and torque is one action and the airframe is the opposite and equal reaction. What I meant by manufacturers building airfoils into the airframe can only take affect when airflow is introduced to these airfoils. Most of these aircraft where built for power and speed, hence the over sized propellers and engines. P-51 for example, inline 12 cylinders Allison engines took up the first 8 feet of the aircraft. Wish I had that engine in my car! LOL

Anyway thats just my opinion.

[ccvi]

My bad. was thinking precession and writing pfactor. precession can't be compensated.

now thinking about pfactor, it probably can't be compensated either for all flying states at least, but at initial takeoff roll it's zero anyway.

[F4UDOA]

Wmaker,

My bad, I meant aileron and rudder, not elavator.

Jodgi,

What they had is adjustable trim that had to be set by hand before flight. So once you were airborne that was it.

Seems strange considering how German machinery seems so well done but their trim system was stone age.

[ccvi]

What in AH limites the torque effect (yes, the real one, where the aircraft rolls to the opposite direction the prop speeds up to and blows the air in, not the yawing tendency) are two things:

The gradient of engine speeds is limited in AH. If you're at full RPM and idle, then push in full throttle, first the prop should spin up to full speed, then create thrust. In AH the speed increase is limited.

The gears are very though, but don't seem to be modeled indivdually. When realoading bombs on the hot pad, the aircraft sinks in a bit due to highter mass. I've never seen it sink in on one gear only, e.g. dropping the bomb on one wing not the other.

One wheel beeing pressed to the ground more than the other also creates some yawing, but with the tough gear I don't think this is modeled.

[Ack-Ack]

This is why torque is modeled how it is currently in AH.

Originally posted by Pyro in another thread
One thing that I mentioned with regards to torque is that the propellor slipstream effects on the wings were being placed too far out thus creating an artificially large force moment. This effect counteracts torque to a degree, an overly large degree in AH until now. The propwash from a propellor comes off in a vortex that corkscrews back over the airplane. In a standard clockwise rotating engine, the vortex strikes the right wing with a downward component and the left wing with an upward component. This increases the effective aoa of the left wing and decreases the effective aoa of the right wing, hence more lift on the left wing and less on the right.

The slipstream continues to corkscrew back to the tailplane where it impacts the vertical stabilizer on the left side which pushes the tail to the right and the nose to the left. This is the main force causing the left yaw on your takeoff roll.

With regards to that, the main factor countering that in AH is the modeling of the tailwheel. All the planes have a steerable tailwheel and that is a change we are looking at as well.

ack-ack

[GScholz]

Originally posted by F4UDOA
Wmaker,

My bad, I meant aileron and rudder, not elavator.

Jodgi,

What they had is adjustable trim that had to be set by hand before flight. So once you were airborne that was it.

Seems strange considering how German machinery seems so well done but their trim system was stone age.

The Germans thought they were unnecessary, and they were. Both the 109 and the 190 had elevator trim. The trim tabs on the ailerons and rudder were set for cruising speed. I wouldn't call the German electric trim system "stone age", considering that the allies were using manual wheels. The 109 and 190 simply didn't need aileron and rudder trim, plenty of other German planes did, and were so equipped.

[Karnak]

Actually, the 109 could definately have used rudder trim.

I have read to many accounts of how tired the pilot's legs would get in a fight or at high speed in the 109.

[PSYKOJR]

why do u think they made the p38s props spit opposite directions so it would eliminate the tourqe problem

[jigsaw]

why do u think they made the p38s props spit opposite directions so it would eliminate the tourqe problem

That's to eliminate the "critical engine". What I haven't been able to figure out is why they spin outside instead of inside like every other non conventional twin I've seen.

[PSYKOJR]

actuallly they spin outside cause it does eliminate engine tourqe cause i watched a show on the p38 and thats what they say it did

[Ack-Ack]

Originally posted by jigsaw
That's to eliminate the "critical engine". What I haven't been able to figure out is why they spin outside instead of inside like every other non conventional twin I've seen.

The XP-38 and Model 322's (RAF version) had inward turning, counter-rotating propellers.  The YP-38 and all subsequent Lightnings had outward turning, counter-rotating propellers which negated the torque when both engines were operating.


ack-ack