F16 turning

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saberrider

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Unread post31 Jul 2018, 13:39

Here is the scenario: at the medium altitude , in clean weather and in a level turn at ( @370 knots/ 6 G's) in the Viper and speed decrease more and more how the FLCS schedule exit from that turn if the pilot keep pulling but not adding any lateral move on the stick ? The F 16 will overbank and go nose low after that,or go nose low but keep the angles of bank the same , or gradually by itself tend to wing level , or hit the limiter for AoA (25 -29)and lower the AoA and nose slices left /right . What's the result of this manner of flying if the pilot itself don't let the stick free?
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sprstdlyscottsmn

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Unread post31 Jul 2018, 15:35

from an aerodynamics standpoint, if the pilot does not change the bank angle then the nose will start to slice down until the gravity assist balances the negative excess thrust. Once at a low enough altitude the plane will speed up as excess thrust becomes available, gradually raising the nose.

Now if this happens before hitting dirt, I can't say.

I see no evidence of the F-16 Auto Leveling due to FLCS. If it gets enough sideslip the downside wing will make more lift than the upside wing (due to sweep) which would notionally push it toward wing level, FLCS might fight that, I don't know.
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saberrider

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Unread post01 Aug 2018, 06:10

sprstdlyscottsmn wrote:from an aerodynamics standpoint, if the pilot does not change the bank angle then the nose will start to slice down until the gravity assist balances the negative excess thrust. Once at a low enough altitude the plane will speed up as excess thrust becomes available, gradually raising the nose.

Now if this happens before hitting dirt, I can't say.

I see no evidence of the F-16 Auto Leveling due to FLCS. If it gets enough sideslip the downside wing will make more lift than the upside wing (due to sweep) which would notionally push it toward wing level, FLCS might fight that, I don't know.
But F16 is a plane with FLCS and pilot feets don't push the rudder in turn to cancel the sideslip like another types,and CG is way back and at lower speed will go nose high not down as I see it in many GA planes. sure it will not have slide slip at all .That way I put the question .
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f-16adf

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Unread post01 Aug 2018, 13:17

What sideslip in a turn? I am a little confused here.

At least when a General Aviation aircraft enters (rolls into) a turn, due to the effects of adverse yaw (the down aileron while making lift, its by product is drag); And yaws the nose in the the opposite direction of the turn. Hence the rudder is used to keep the nose straight. My first FI burned that into my memory.


Modern jets use an ARI in a turn, I believe. The F-16's FCS automatically compensates for it, I think. And there is no need for the pilot to put his feet on the rudders. Hornet does the same thing.


You can also use the rudder (on "some" (flaps position/placarding) light GA aircraft, C-172/PA-181) when on "high" final approach to enter a slip. So you will lose altitude without gaining airspeed. Hence the airplane is technically crossed controlled (Aileron is in the direction of the X wind, rudder is opposite of that).
Last edited by f-16adf on 02 Aug 2018, 01:50, edited 1 time in total.
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johnwill

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Unread post02 Aug 2018, 01:17

One thing saberrider may not understand, a turn does not result in yaw. It is the roll into a turn that does. Once bank angle is established, there is no aileron deflection, thus no yaw moment, no need for rudder from manual input or ARI. Another thing, it is not just the down aileron that causes drag and yaw. Up ailerons also produce drag, usually less than the down aileron. Why less drag on up aileron? Because with positive AoA, air pressure on top of the wing is less than on bottom of wing.
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saberrider

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Unread post02 Aug 2018, 06:34

johnwill wrote: Once bank angle is established, there is no aileron deflection, thus no yaw moment, no need for rudder from manual input or ARI. Another thing, it is not just the down aileron that causes drag and yaw. Up ailerons also produce drag, usually less than the down aileron. Why less drag on up aileron? Because with positive AoA, air pressure on top of the wing is less than on bottom of wing.
The amount of deflection is not the same for the down as the up ailerons this thing is that I knew for GA planes , the turn is technically an pull up , but l seeing many F16 turning around at slow speed and nose -tail are nothing parallel to the ground in level turn (nose is little up to the sky and jet is bank to the inside of the turn)the rudder is up to the sky .If slow down more what's happening ?This is what I want to know only for the F16?

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