No, airplanes cant remain stationary as helicopters can. This is because remaining stationary means it has zero velocity and hence no lift is produced to cancel the weight.

airplanes can teoreticaly stay stationary in reference to earth, if the headwind speed is eaqual to the speed of passing air required to generate lift.

It is obvious airplane with zero speed will stall because of zero lift and presence of gravitational force. But helicopter can hover and stay standstill with zero forward speed, because of combination of three simultaneous motions of its blades i.e. rotational, pitching and flapping motions.

Max Andreas Minev Quite true. A headwind of sufficient strength can generate a relative wind that will create the necessary lift and overcome drag to keep the aircraft stationary. You can observe this by watching birds fly. Seagulls will often fly in high wind gusts with their wings extended and stationary. They can often be seen to hover stationary above the ground.

Dear Douglas Nance,

Could you please mention a real practical example that such case has happened for an aeroplane and not birds?

First, helicopters don’t have propellers, they have Rotor Blades. Propeller is for fixed wing aircraft. Second, yes, the aircraft with fixed wings can have 0 ground speed if they fly into a headwind which is as much as aircraft stalling speed. I have actually gone backwards with a T-37 at 10,000 feet by a slow flight, putting the aircraft into a strong headwind.

Only the VTOL aircrafts can do that, because of the hability of vertical take-off and landing capability. Here are some of the aircrafts that can do it: Harrier, AW609, V22-Osprey, V-280 Valor, among others.

You can see many others here https://en.wikipedia.org/wiki/List_of_VTOL_aircraft

With a headwind strong enough, yes.

I fully agree on the answer that aircraft can stay flying at zero speed only if the speed is related to the ground but the aircraft is flying against a wind whose speed has the same module of the aircraft sppeed but in oposite direction: this is like swimming in a river whose stream is oppsite to the swimmer direction.

In any case a flying object can stay in the air without movement referred to the ground and to the air only if it is lighter than air, i.e. it is a balloon or a dirigible: it will fly for the Archimede's principle. Another example of a flying object that can fly at zero speed vs. earth surface is a geostationary satellite: in this case the gavity force is balanced by the centrifugal force, but it need to stay at around 36.000 km and made a full orbit in 24 hours, the same angular speed of Earth.

The required lift necessary to compensate the weight of an aircraft and to keep it off the ground is proportionally to the square of the speed of the air streaming around its wings. A fixed wing aircraft gets this speed by moving forward in the air using an engine (or gravity if it is a glider). A helicopter uses the same effect but generates the air flow itself by rotating its rotor through the air.

If an aircraft in the air is not moving relative to the ground it is because the wind is as fast as necessary for producing the lift. The aircraft is in this case moving relative to the air with the required speed to get the needed lift, but the wind is moving to the ground with the same speed so that it looks as if the aircraft remains stationary in the air.

It is a very interesting question and very useful when explaining the forces acting on any aerofoil.

Simple answer is - yes it is possible hypothetically.

From Newton's second law of motion, we know that forces on an object produce accelerations. To understand we need see the forces which act on any aerofoil. There are four major forces acting on an aircraft; lift, weight, thrust, and drag .

for any object immersed in a fluid, the mechanical forces are transmitted at every point on the surface of the body. The forces are transmitted through the pressure, which acts perpendicular to the surface. Since the fluid is in motion, we can define a flow direction along the motion. The component of the net force perpendicular (or normal) to the flow direction is called the lift; the component of the net force along the flow direction is called the drag. Thrust is the aircraft power that is pulling it ahead. Similarly the lift is counterbalanced by weight of the aircraft, if the lift is more than the weight then the aircraft stays afloat otherwise it will stall.

Whenever thrust is more than the drag, the aircraft will accelerate and the velocity will increase.

Now hypothetically speaking if the airflow (Head wind component) equals the thrust (lift should be more than weight to prevent stall) then the aircraft would be stationary. In navigation terms the True Air Speed (or equivalent Air Speed for the lift equation) of the aircraft would be sufficient to produce lift but the Ground speed of the aircraft will become zero.

If the thrust from the engine and propeller is greater than the gross weight of the aircraft than it is possible to climb straight up. This can be post stall with no wing lift. In order to hover I believe requires that the ailerons are located inboard enough in the propeller slipstream so that the pilot can counter act the engine torque. I think this is within the capabilities of some high performance aerobatic aircraft, but i have not verified it.

Mohsen Jahanmiri Of course, consider a Hurricane Hunter aircraft flying at 5,000 feet in near the eyewall of a certain Category III hurricane. Stall speed of the aircraft is about a hundred knots, so if the pilot turns into the wind and throttles to an indicated airspeed of say, 110 knots, the aircraft will be effectively stationary over the ground plane. As a similar scale problem, wind tunnel tests do the same thing all the time. you can tell by the point where the force balance indicates the scaled aircraft weight. In short, this is just a problem in Galilean Relativity.

Douglas Vinson Nance

Hypothetically may be right but not in real life. Only a VTOL aircraft is able to do it without any problem. Otherwise to control an aircraft in a standstill position with a headwind of suppose 100 knot is impossible. Regarding wind tunnel test, we keep an aircraft on an stand while passing airstream over it.