What actually changes an aircraft's heading in turn?

ILSstud

ILSstud

Well-Known Member
What actually changes an aircraft\'s heading in turn?

While looking through my "flying notebook" as I call it, I started to wonder to myself if the Hcl is what actually pulls an aircraft through a turn, what changes the actual heading? I mean if it just a horizontal component than wouldn't the plane simply move laterally across the ground? Here's what I was able to come up with...don't know if it is right or wrong.

In a turning aircraft you have both forward and sideways motion. So as such the relative wind will shift (just draw a vector triangle) so the plane will pivot into the relative wind as it does after takeoff from a crosswind for example. So that is what actually changes the plane's heading...a constant crab so to speak? Is my assumption correct?
 
Re: What actually changes an aircraft\'s heading in turn?

If you get a chance read Stick and Rudder.

You are on track, the plane would move sideways if it weren't for the vertical stabalizer that constantly aligns the nose with the direction of motion.
 
Re: What actually changes an aircraft\'s heading in turn?

A move challenging question is what actually makes a car turn. It seems obvious at first glance, but it's not!
 
Re: What actually changes an aircraft\'s heading in turn?

A steering wheel, duuur!
smile.gif
 
Re: What actually changes an aircraft\'s heading in turn?

[ QUOTE ]
A move challenging question is what actually makes a car turn. It seems obvious at first glance, but it's not!

[/ QUOTE ]

Same thing that makes an airplane fly.


MONEY.
 
Re: What actually changes an aircraft\'s heading in turn?

[ QUOTE ]
A move challenging question is what actually makes a car turn. It seems obvious at first glance, but it's not!

[/ QUOTE ]

Horizontal component of drift?
 
Re: What actually changes an aircraft\'s heading in turn?

A combo of the direction of the front wheels and friction between the wheels and the ground?

A trickier question might be why you should not brake during a turn?
 
Re: What actually changes an aircraft\'s heading in turn?

[ QUOTE ]
A trickier question might be why you should not brake during a turn?

[/ QUOTE ]

"Should not" is kinda, sorta, maybe true. For most people, braking in a corner could transfer weight to the front wheels too quickly and cause the car to oversteer (you're reducing the weight on the rear wheels). But if you look at the opposite problem and you don't put a decent amount of weight in the front during a corner (so that the front wheels have good authority), you could understeer and end up hitting a guard rail, tree, cliff, etc.

What I like to do in my little Toyota pickup (not just race cars do it
wink.gif
) is to do a "trail brake" into a corner. You delay the application of the brakes before the corner so that you're still bleeding off the brakes while you're adding your steering input in the corner. This transfers the weight to the front end very evenly, and if done correctly, could gain you some speed around the turn. Personally, I gain 5-10+ mph through corners by doing this one thing.

Wait...I thought this site was about planes?
smile.gif
 
Re: What actually changes an aircraft\'s heading in turn?

Thanks for the info.

I was thinking more along the lines of the direction of friction between your tires and the road surface though. When your car goes around a curve the entire direction of friction is pointing to the inside of the curve, keeping the tires from slipping to the outside. However when you apply the brakes you are now diverting some of the friction direction to slowing you down, thereby splitting the friction between pointing to the inside of the curve and pointing to the rear of the path of movement. Less friction keeping your tires from slipping to the outside means that the speed at which you will start skidding will lower.

This isn't an absolute rule, though. If you were about to go around a sharp curve at 100 mph, I think it would be wise to put a certain amount of pressure on the brakes.
 
Re: What actually changes an aircraft\'s heading in turn?

[ QUOTE ]
Thanks for the info.

I was thinking more along the lines of the direction of friction between your tires and the road surface though. When your car goes around a curve the entire direction of friction is pointing to the inside of the curve, keeping the tires from slipping to the outside. However when you apply the brakes you are now diverting some of the friction direction to slowing you down, thereby splitting the friction between pointing to the inside of the curve and pointing to the rear of the path of movement. Less friction keeping your tires from slipping to the outside means that the speed at which you will start skidding will lower.

This isn't an absolute rule, though. If you were about to go around a sharp curve at 100 mph, I think it would be wise to put a certain amount of pressure on the brakes.

[/ QUOTE ]

I think you would make a good engineer.
 
You must log in or register to reply here.
Back
Top