Can a airplane stand in a still sky?

 In simple way i can say that as far as passengers plane are concerned, they do not stand still in the air.
Because  laws of aerodynamics doesn't allow it.
Because there should be flow over the airplane(wind),such that it will in stable state,if not it will reach the ground due to gravitational pull.

There are other fighter aircraft called VTOL(vertical take-off and landing) .that can stand in a still air(technically called hovering).

• The engine outlets of these aircraft are orientated downwards in order to hover above the ground.

• 

  HARRIER(AV-8)

• Requires a lot of fuel, not particularly efficient.
• They do this by thrust vectoring.

THRUST  VECTORING.

Note: Officially, the Osprey (V-22), Harrier (AV-8), and other fixed-wing VTOL aircraft are Not officially considered to be airplanes. They belong to a different category of aircraft known as Powered Lift.

AN AIRPLANE CAN HOVER IF AND ONLY IF:

• Enough headwind
• Enough engine power
• Enough lift

A tailwind is a wind that blows in the direction of travel of an object, while a headwind blows against the direction of travel. A tailwind increases the object's speed and reduces the time required to reach its destination, while a headwind has the opposite effect.

Hope you understand!!

Edit,suggestion,correction and appreciation are most welcome.

Yours chandra shekar.