DescentBB

Watching the movie Tora Tora Tora I see the planes taking off from the carriers have their main wing flaps in the down position. Shouldn't they be in the up position?

No. http://www.grc.nasa.gov/WWW/K-12/airplane/flap.html

It really depends on the aircraft in question, but in general most aircraft have a take off setting for the flaps. The idea being that there is a medium setting that increases lift without increasing drag very much.

Any minute now...

im WWII wood, just about all japanese planes used flaps when taking off

Good site Flatlander.

Bernulis principle (even if I can't spell it)


The airflow across the top of the wing takes less time then going across the bottom causing lift...

So when flaps are down half or full more lift is created plus easy to manuver at lower speeds...

Oh no...the japs are blowing up the PBY's...I'm still watching the movie

"Awaken a sleeping giant and filled him with a terrible resolve" Admiral Yamamoto.

Too bad bin Laden didn't watch Tora Tora Tora.

Couver_ wrote:Bernulis principle (even if I can't spell it)

The airflow across the top of the wing takes less time then going across the bottom causing lift...

So when flaps are down half or full more lift is created plus easy to manuver at lower speeds...

More accurately...

Bournelli's theorem (Not a law, or principle) states that air travelling over the top portion of the wing must travel faster to rejoin air travelling under the wing. The faster air causes a low pressure area on the top of the wing, thus providing life. The vast majority of the lift is generated at the top of the leading edge, where the air is accelerating the most.

However, most people are under the impression that this is what keeps an aeroplane up - THEY ARE WRONG.

Lift accounts for a small percentage of what keeps an aeroplane up. The rest is because the wings have an angle of attack which causes A LOT OF AIR TO BE DEFLECTED DOWNWARDS, thus keeping the aircraft UP.

An aeroplane will stall if power is not applied. To make an aeroplane glide, you have to pitch the plane forwards such that the airflow is no longer deflected downwards substantially, or the downwards deflection is offset by the foreward momentum of the plane.

Powered planes don't actually require a wing-shaped win at all. They could have completely flat wings and still fly. But they ARE much more efficient and cause less drag when the wing has a nice profile.

Remember: Glide angle = Lift / Drag.

The most critical of all wings are those made for gliders, and here you'll see the ultimate expression of wing profiles.

To make matters more complex, the shape of a wing should change at velocity. i.e. one wing profile is most efficient at a certain speed. This is why jet fighters sweep the wings for speed, in effect it reduces the profile of the wing, and reduces drag.

In the future, wing shapes will change automatically (the profile) with smart memory-alloys which change shape when a voltage is applied to them.

Jagger wrote:Any minute now...

Right on schedule

Mobius wrote: More accurately...

Bournelli's theorem (Not a law, or principle) states that air travelling over the top portion of the wing must travel faster to rejoin air travelling under the wing. The faster air causes a low pressure area on the top of the wing, thus providing life. The vast majority of the lift is generated at the top of the leading edge, where the air is accelerating the most.

That's a good way to put it in layman's terms.

It's Bernoulli.

I really have to give Mobius credit because it seems like no matter what the topic is, he can always jump in with an opinion and a lot of related information.

I wonder if he just picks up books on random subjects and reads them regularly...

He must do a lot of skimming then

lol yeah maybe, I wouldn't know. I'm too uneducated on subjects like airplane flaps...

And actually it depends on the aircraft and wing design for what makes more lift. Mobius you are generalizing too much. Angle of attack is important on some designs, but not the be all end all of what keeps an airplane in the air. If you have a large jet-liner, the wing has a neutral camber and uses angle of attack to support itself, especially because of the speeds it is flying. However, with a small airplane like a light civil, it depends on the airspeed of the vehicle in question. At efficient airspeeds almost all of the lift is created due to the above described principle. If you were to drop to the back side of the lift/drag curve on the same aircraft (btw this is where the term "you are behind ther power curve" comes from), then angle of attack plays more of a roll in keeping the aircraft up as well as MORE THRUST.

You can't just say that angle of attack does all the work all the time. Your glider example is the perfect.....example......

Thanks Hostile, for a moment there.... I thought I was going to have to bash Mobius for google'n

Mobius wrote: The faster air causes a low pressure area on the top of the wing, thus providing life.

Really? That's unbelievably and creationally cool!

BUBBALOU wrote:Thanks Hostile, for a moment there.... I thought I was going to have to bash Mobius for google'n

and not bash on me................


Hostile, i couldnt have said it any better. it is totaly dependent on the aircraft and its flying profile