How do airplanes turn?

[siucavflight]

An aileron does not change the camber of a wing. They change the angle of attack. The effect is a banked airplane resulting in a horizontal compentent of lift. Your buddy'd CFI didn't teach him very well.

Someone is not theaching their students very well, but then I guess that is what you would expect from a CFI who is "tired of taching". It changes both numnuts.

 

[mar]

It's the weather vaning silly!!!

Ailerons do NOT turn the airplane. They BANK the airplane.

What happens after you bank the airplane is that you change the horizontal component of lift.

After you change the horizontal component of lift you change the relative wind.

And thanks to the weather vaning tendency (due to the vertical stablizer) the airplane changes heading...or turns!

It's due to the vertical stab and the *change* in the relative wind.

Ailerons only get it started.

Most DEs piss me off. I've only met two who knew what they were talking about.

Good luck.

 

[NYCPilot]

I'd like to know how simple an explanation your friend gave thats was unsatisfactory. Maybe he was way off.

All CFI applicants should be able to explain such a basic concept. If the examiner asked how specifically the "Aileron" turned the plane, a proper answer would be that by lowering the aileron on the outside of the turn and raising it on the inside results in an increase in lift on the outside and a decrease of lift on the inside. This occurs due to the outside aileron increasing the camber and angle of attack on that wing. All you're doing in a turn is creating an imbalace in lift between the wings. One wing produces more lift than the other and causes a portion of the the vertical lift component to shift slightly into a horizontal component. Since you are diverting some of this vertical lift into horizontal lift, you will need to increase back pressure to maintain altitude. The back pressure is required since lift that was being generated to support the weight of the airplane has been taken away or shifted, you will need to develop more lift vertical lift to compensate for this. There is also a need to increase back pressure due in part to the increase in load factor. Load factor results when the airplane is moved from steady unaccelerated flight (straight and level as well as a constant speed climb may be consided as such). This added load factor increases the effective weight of the airplane and thus requires a greater amount of air lift to be generated in order to support this additional "phantom" weight. So this will also increase the amount of lift needed to be generated during a turn. While increasing the back pressure you are increasing the angle of attack as well which is the reason you generate more lift. You can increase lift by either increasing velocity or AOA. Here we are initally only using AOA. This increase in AOA has effectively increased drag (as a by product of lift) and so now the airplane begins to slow down due tothe retarding force of drag. In order to maintain your entry speed, a power increase is required to comepensate.

Many pilots mistakely believe that rudder is used to help an airplane turn. All the rudder does is to eliminate the adverse yaw that is created by the additonal drag created by the aileron being moved down. Oncethe controlsd are neutralized, rudder force may be relaxed unless torque is causing an yawing.

It is true that in order to make a coordinated constant speed and altitude turn you require coordinated use of ailerons, rudder, elevator and power.

 

[Almerick07]

His answer seemed pretty clear stating the ailerons deflect the airflow either up or down either increasing or decreasing lift and they worked together to roll the airplane. He said he drew it, used a model airplane but the examiner wanted to hear the terms angle of attack and camber.
He was failed on the premise of lack of instructional knowledge by using the term deflection, the examiner said it confused him because he thought of ping pong balls. My buddy said he got a little into a changed horizontal component of lift and what not but wanted to keep it simple because the examiner said he was a student pilot.

That is the story and after doing a little research on my own, i came across the NASA website where it actually uses the term deflection....

http://www.grc.nasa.gov/WWW/K-12/airplane/alr.html

third paragraph down......

 

[NYCPilot]

Well, I have to admit that if he excluded the term "angle of attack" I can see why the examiner was not satisfied. That is exactly what the deflected aileron is changing. I don't think the term deflection is incorrect as this is the physical movement of the control surface, but it deflects so that it can change the angle of attack.

 

[aperson]

I was taught that money made the airplane fly/turn/etc.

 

[NYCPilot]

I was taught to read the previous posts before reposting the same comment.

 

[UA-RESURRECTED]

When you turn the yoke or deflect the stick, the ailerons move in opposite directions. This causes a gyroscopic effect, which is brought on by the pull of the Earths gravitiational field. This effect causes the airplane to become heavier on one side and that side will start to be pulled torward the center of the earth while the opposite side is actually pulled upward by gravitational forces induced by the sun. Once the ailerons are nuetralized, these two opposing gravitioional forces become equal, and the airplanes stays at a specifc bank angle. Now the airplane is set up for a turn. The airplane turns because the thrust path is now lined up with the curvature of the Earth. It's as simple as that.

 

[FN FAL]

I was taught to read the previous posts before reposting the same comment.

I was taught that planes turned because pilots know that you can't make straight in approach to the Pilsner Urquell.

 

[mar]

I forgot all about that!

This causes a gyroscopic effect, which is brought on by the pull of the Earths gravitiational field.

Oh right!

Thanks for reminding me.

Can you elaborate on the effect of precession and magnetic dip on the turning aircraft?

Also, how much of a factor is Coriolis Effect?

 

[cezzna]

I once talked to a private pilot who told me that he had to keep retrimming his airplane nose down after time in cruise. He then explained that this was due to the curvature of the earth. Mybe he took his ride with this DE.

 

[MTpilot]

That is awesome! I went to space one time all I had to do was stop trimming down! That's all Rutan and those guys did.

 

[minitour]

Also, how much of a factor is Coriolis Effect?

Force...Coriolis Force :beer:

-mini

 

[UA-RESURRECTED]

Also, how much of a factor is Coriolis Effect?

The deal with the coriolis effect, is that most props have to move in a clockwise dirrection as seen from the cockpit. If a prop was made to rotate in the opposite dirrection, the coriolis force would negate its movement, and you wouldn't get any thrust. This is why you should never fly a prop-driven aircraft across the equator. Once you're on the other side, you will lose all thrust and will fall out of the sky.

 

[NYCPilot]

I was taught that planes turned because pilots know that you can't make straight in approach to the Pilsner Urquell.

Yum. Pilsner Urquell. Great beer...I know a place in Park Slope bklyn where they've got'em for only $4 - compare that to $6 a piece in Manhattan....and thats at a dive price.