If I fly close to stall speed with a STOL plane and gust of 20kts tailwind comes at me,it will cause sudden reduction in lift ,becuase plane has inertia so it can not accelerate instantly.
How dangerous is this situations?
Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. It only takes a minute to sign up.Sign up to join this community
If the wind is constant, it doesn't matter. The aircraft move relative to the surrounding air, and doesn't care how the air moves relative to the ground. If the aircraft has an (true) airspeed of 100 knots, and a tailwind of 100 knots, it's flying 200 knots relative to the ground. If the aircraft turns into the wind it will stlil fly 100 knots relative to the air, but 0 knots with respect to the ground.
The danger comes with gusts. If the aircraft is flying 100 knots airspeed in a 10 knot tailwind, it is flying 110 knots relative to the ground. If there is a gust of wind increasing the tailwind to 50 knots in an instant, the groundspeed will still be 110 knots. The airspeed will thus suddenly drop to 60 knots. That's the kind of speed drop that can cause stalls and crash aircraft.
No. Any airplane (big or small) flies relative to the air in which it is moving. So, if there's a 10 knot tailwind, the airspeed of the plane will remain the same, while the ground speed is increased by 10 knots. And since ground speed doesn't affect lift, then there is no change in lift produced.
Having said that, there are two situations where the wind speed is relevant:
When the wind speed changes rapidly (called wind shear), the airplane's inertia keeps it from changing speed instantly. If the shear is very severe, this might lead to a momentary loss of lift, which the passengers will experience as slight turbulence.
During takeoff and landing, the airplane is actually touching the ground, therefore, ground speed suddenly becomes relevant. This is why airplanes always take off and land into the wind whenever possible, to get as much lift as possible at a lower ground speed.