Page 56 - Grasp English B2 (Student Book)

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Science Aeronautics

There are a number of factors affecting the the plane’s speed, but the air flowing over it.
success of a take-off, so no two take-offs will As the air flows over the wings of the plane, it
ever be the same for the pilot flying the plane. creates the Bernoulli Effect. Because there is
Some factors, such as wind direction and higher air pressure under the wing than on the
speed, can make take-off more challenging, top side, it creates lift.
though flaps on the wings can be lowered to Once in the sky, the plane’s landing gear
help create more lift. is retracted to make the plane more
Whilst the plane is stationary on the runway, aerodynamic and the pilot will take the
the engines are revved and when they reach plane to its cruising altitude. Cruising altitude
a certain percentage of full power, the pilot tends to be between 25,000 and 40,000
releases the brakes. This causes the plane to feet for most flights. At high altitudes, the
accelerate at high speed along the runway. atmosphere becomes thinner, meaning there
As the plane speeds along the runway and the is less resistance to objects passing through it,
nose begins to lift off the ground, the airspeed making the flight more efficient.
increases: airspeed is not a measurement of

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