Question:

With reference to the wind question..?

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1)If G/S or TAS (G/S in this case would make no sense

) of an aircraft is 80 and tailwind 120,how would an aircraft be able to sustain itself in the air?What happens to relative wind over the wings?If the tailwind could push the entire aircraft forward adding to its speed,it would also be doing the same at the wings.So now let me know if the air over the aerofoil is moving forward or backward?? And how does the aircraft fly in such a case??

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  1. The aircraft is not stationary in the air allowing the wind to flow over its wings.  In order for the aircraft to be flying at all, it need to be moving forward (relative to itself) at a speed great enough for the airflow over the wings to allow flight.  Lets say hypothetically that is the 80 knots you mentioned above.  As the aircraft flies, air molecules are moving over its wings from front-to-back at 80 knots.  Simply because the air is moving relative to the ground at 120 knots does not mean anything to the airplane.  Once an airplane is untethered from the ground, it is (for the most part) free of all the constraints that we tend to place on it by thinking about the world as someone tethered to the ground by gravity.  It simply does not matter what the winds aloft are doing.  The airplane does not care whether the wind aloft are moving 100 or 200 or 500 knots.  Aerodynamically, nothing changes at all.

    In high winds, pilots are the ones who care.  We tend to like to know where we are and when we are going to get to our destination, but from a purely aerodynamic standpoint, winds aloft are simply a question of relativity.  Is the wind moving 120 knots relative to the ground?  Or is the ground moving 120 knots relative to the wind?  The answer is yes.  It doesn't matter.

    Think of a river moving along at 5 knots.  If you were to tie a boat up so that it could not flow with the stream, it would sit there and move at zero knots relative to the shore but at 5 knots relative to the river (because the river flows right past it)  If you untie the boat, it floats downstream at 5 knots relative to the shore, but at zero knots relative to the river.  This is much like our example.  Once the airplane is untied from the ground, it ceases to be in the frame of reference where speed is measured relative to the ground and enters one where speed is measured relative only to the air molecules directly adjacent to it.


  2. Flying in strong winds aloft is great or a bummer depending on which direction you are going. Made a flight one day TAS was 120 and the winds aloft were 50 knots, took forever to get there, the ground speed was only about 70 knots but on the way back wohoo ground speed was 170 knots. Talk about getting there in a hurry.

  3. the aircraft is moving forward at 80 knots through an airmass. The fact that the airmass is moving relative to the earth does not hinder the aircrafts flight. A tailwind of 120 knots means the aircraft moves at 200 knots over the ground. A headwind of 80 knots would cause the aircraft to remain stationary above a point on the earth, i.e. g\s 0kts but tas 80kts.

  4. air speed and ground speed are different.. resultant air speed http://en.wikipedia.org/wiki/True_airspe...

    read this link  some day if you fly you have to make a decision to go on or turn back.. not enough fuel to make it to the destination. ok knowing this can save a life.

  5. If the TAS is 80 then the airflow over the aerofoil is moving backwards from the front to the tail. (That is how the pitot head is registering the speed).The tail wind is the result of the whole air mass being pushed in that direction. The only effect would be that the ground speed would be 80 (TAS) +

    120 (Tail Wind) = 200 knots.

    The aircraft is flying because of its forward indicated air speed.

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