Remodeling the flight model

[straffo]

how much lift create a horizontal stabilizer compared to the wings ?

I mean the purpose of the stabilizer is more attitude control than lift or I'm mistaken ?

[mjolnir]

You're right straffo, it doesn't produce very much lift compared to the wings.  The amount of lift produced is a function of, among other things, the surface area of the airfoil.  The more air passing over it, the more lift you get.  Since the horz stab is a fraction of the area of the wings, you only get a fraction of the lift.  The whole purpose is just to keep the airplane in equilibrium, because if there was only one surface on the plane producing lift, the CG would have to stay right dead center on the lift vector at all times (otherwise you'd have rotation about the CG), and we all know that doesn't happen.

[straffo]

Thank you !
I know it's not directly related to this thread but  I've found some nice and funny littles images to explain how the commands work :


see here : http://www.chez.com/shgente/histoire/vole1.html

[GRUNHERZ]

Wow straffo, RED X in French really says a lot...

[straffo]

fek ...

No problem , I'll scan my crayon book tonight

[clouds]

Hey guys, you are talking about airplanes having a normal or positive stability design, while there are also airplanes with a relaxed stability design or Unstable (one overall the F16 Falcon) in wich the tail is used exactly opposed to the normal stable airplanes.

In theese airplanes (tending to drop their backs) the tail is used to raise the back so increasing the total lift, while the others have to pitch dn the tail to increase the AoA so loosing precious lift.

But why some are stable and others unstable planes ?

Because of the position of the CG related to the main lift vector.

If the main lift vector is applied infront the CG, then the plane tend to drop its back so it is called unstable, while if the CG is infront main lift vector the plane tends to drop its nose and it is called a stable plane.

If you can build a paper plane, you can test this soon, just moving a little weight from the nose to the tail, and you will see the more the weight comes near the main lift vector, the more the plane is transforming from a diver to a glider.

When the weight comes behind the main lift vector, the plane become uncontrollable at all (it just needs a flight control computer to fly stable to prevent it noseup tendency) just like the F16 Falcon does.

So this is the reason the F16 is one of the most meneuvering aircrafts, because it is unstable and its flying abilities are controlled by a very fast Flyght Control Computer, but if unfortunately the flight computer crashes (then the Augmentation Stability Control System = ASCS doesn functions too) the pilot will die almost instantly (someone said the accelerations doubles every quarter of a second or more so in 1 sec you hit 8G that's a kind  of dive against the wall).

A fast computer controlls all the aspects of the flyght in a F16 but, a fast computer is nothing without a fast mean to transmits all the commands tho the control surfaces, so here is the Fly by Wire.

All the commands are sent to the control surfaces by means of cables that serves electrical motors (not hydraulic piping or direct connection with the stick).

I was reading of some F16 pilots get confusin seeing the tails moving constantly up and dn while the stick was held fixed for the horizontal flyght. The flight control computer were doing its job trying to maintain the aircraft inside the flight envelope.

I'm sorry for my bad english, I hope in your intelligence if I was not too much clear.

What a strange thing to talk about the F16 in a WWII forum

[Vulcan]

Originally posted by GScholz
How would you know?! (sorry, couldn't help myself )


Wow, you need stereoscopic vision to get a drivers license? Here they let one-eyed ppl drive. They just have to have their head on a swivel to cover their blind side.

You can't judge a 100 meter distance? I find that odd since I do that with one eye all the time, 200 meters and 50 meters too (pistol/rifle shooting).

This is just from stuff I read (cause of my eyes). Apparently stereoscopic vision is the dominant factor out to 20 feet (ie other cues hardly get a look in). At 100 feet the balance changes to textural and other cues. However stereoscopic vision does come into play beyond 100 feet with objects in motion.

As for me not being able to judge 100 metres, yeah its wierd. But perhaps your stereoscopic vision gives you a benchmark for one eyed views. Some of the stuff I've read indicates that people with binocular vision still have way better depth perception than those who have only ever had non-binocular vision. ie if I guy is born one eyed, his vision will always suck, whereas if his eye got poked out when hes 20 he'll have a reasonable level of depth perception.

Its a complex thing, medical science still doesn't understand it fully. Take me for example, I regained vision in my right eye but never regained the stereoscopic vision.

When shooting you can hold a rule to my pattern vertically and ever hole will line up perfectly (just my breathing sucks).

[Straiga]

MJOLNIR your wrong I learned this stuff when I was 14 taken my private written exam. Are you a pilot? I mean a real pilot?

[straffo]

Originally posted by Straiga
MJOLNIR your wrong I learned this stuff when I was 14 taken my private written exam. Are you a pilot? I mean a real pilot?

A proper rebutal would have been better than a personal attack/insinuation

[Hyrax81st]

(clipped out this part to respond to)

One of the major changes we’ve made is how we model the forces on the plane. We wanted to increase the number of force points by about an order of magnitude or even more if necessary. For example, prior to this the wing was split up in large chunks with the applicable forces applied to each chunk. In level steady flight this is fine, but it shows its limitations when you get outside of it. Now we have it split up into a lot of small pieces...

The biggest problem flying in WWIIOL was the number of objects apparently being sent to my FE whenever I entered a sector or overflew a town with bunches of GV's below... My framerate would literally go to 1 (thats, ONE) FPS until I cleared out of the area. This may have been a function of Cornered Rat Software trying to send me too much information/update about the relative states of all the little bitty sections of armor on a tank that they kept track of for "realistic" damage modeling purposes (x the number of GV's that were down there) --- but it truly sucked to be in a Stuka divebombing and not even be able to get a screen refresh between the time you dropped and the time you AUGURED.

Be really careful (please) about sending too much data for all the surfaces of all of the objects you are trying to make more realistic. Otherwise, it'll be even more bogged-down in a major furball than it already is...

[Vulcan]

Hyrax81st the problem you're experiencing is completely different.

What HTC intend to do is increase the fidelity of the flight model. Each aircrafts flight characteristics are only modelled on the local PC, with positional information being sent to the server. So no this won't kill your framerate.

In WW2OL there are many factors involved in the framerate killing. The biggest being the code itself, many believe its not very effecient (and I'd agree). The landscape and towns also load as you fly over, and I get the feeling other objects such as tanks do as well. I believe some objects also cause framerate hits because of the number of facets vs the engines effeciency (in the early versions of WW2OL you could figure out where inf or tanks were hiding by moving your gun around and watching the FPS go down). If you don't have sufficient RAM to cache objects you notice immediate framerate hits. CRS have stated the intend to address the issue with the new graphics engine they're working on, and are looking at reducing the type of object data sent to aircraft vs infantry vs tanks.

Playing ww2ol makes you appreciate HTCs effecient code and damn fine netcode (in AH cons don't disappear for 30 seconds).

[clouds]

I perfectly agree with you about WWIIOL that's the reason I didn't get the account in that game.

Friends of mine having PCs much more performing of mine had the same FPS problems of me so it seems not to be the PC causing problems like instead the code does.

[mjolnir]

Originally posted by Straiga
MJOLNIR your wrong I learned this stuff when I was 14 taken my private written exam. Are you a pilot? I mean a real pilot?

Straffo was right, but since you ask, yes, I am a pilot IRL.  Since this line of discussion really has no bearing on what Pyro was asking for (he obviously understands aerodynamics), how about we move this to the O' Club if you want to continue your charade?  I'll keep an eye out for your thread.

[Straiga]

Todays jet fighters are built very unstable. The cg locations are vastly different between airplanes . Cg locations can change in flight.
Swept-wing configuration airplanes (F-14s-F-111s)on these airplanes the center of pressure moves in a far range for and aft and so can the CG. Augmentation computers make the planes able to fly correctly. The more unstable the more manuverable.

In WWII there where no such computers. Planes vary in weight, size and shape. Some airplanes where stable and easy to fly some with a lot of dihedral in the wing, some where not that easy to fly. Due to cg locations in relation to the center of pressure determines to a great extent the logitudinal stability of the airplane, either neutral, negative or positive. All airplanes have a cg moment. Some planes can fly out of there cg moment buy burning fuel off, making the planes less stable or some can fly into the cg moment becoming  more stable. The horizontal stabilizers on most WWII fighter airplanes where set in an negative angle of attack and the positive camber of the horizontal stab was inverted having the negative camber on top. Producing lift in a downward moment to balance the airplane in flight. The center of pressure of the main wing can move for and aft or increase and decrease depending on the speed of the airplane or changing the camber of the wing (Slats, Flaps) or angle of attack. That is why there are pitch and trim changes associated with airspeed changes.

[clouds]

Uhm..........Straiga you'r right except for......F111 and F14 are securely not the most meneuverables of all and so not the most unstable planes actually we could have the pleasure to see over our heads and more, afther that period in wich all were fixed on the forward swept wings they understood maybe the planes could have very good flying performances withouth have to move the wings like birds does (check out for F15, F16, F18, Mig29, Su27 etc, etc).

Some others were designing planes with a sort of forward swept wing that were a one piece wing swepting digonally one tip forward and the other backward very very bad to see (fortunately this was only a prototype).

Others were designing airplanes with inverse arrow fashion (recalling LW projects newer built because of the time tecnology did not permitt that).

And......wife is playin the adunance for dinner.......bye;)