Takeoff, according to REStARTS (Raising European Students Awareness in Aeronautical Research Through School-Labs), is the phase of flight when an aircraft goes through a transition from moving along the ground (taxing) to flying in the air.

Once the doors of the aircraft are closed, the pilot and the co-pilot in a commercial jet, go about completing several internal checks, some of them before the engine is switched on and some when the engine is running. Just before take-off, the engine is run at full power.

After completing all the checks, the pilot calls on the radio saying he is ready for departure. Just before that, the aircraft moves slowly from where it has been parked in the runway. This is to ensure that no damage is done to the wings, which are actually bigger than what they seem to be while sitting on a plane.

At that time, the engines, particularly piston engines, are run up at high power to check for engine-related issues, which creates considerable noise.

Only when the Air Traffic Control (ATC) clears the aircraft for take-off, does it start moving from its position before commencing its flight. Now comes the tricky part, and here is where the pilot’s full experience gets played out. Once the aircraft starts moving on the runway, the pilot starts accelerating to full power and as the plane starts picking up speed, it tries to leave the ground, but the pilot holds it on the ground until it reaches the optimum speed for takeoff. This is to avoid the danger of a stall if the aircraft is at a slower speed. According to pilotinstitute.com, as the aircraft moves faster, there is more air flowing over the aircraft wings. According to a principle of aerodynamics called Bernoulli’s Law, fast-moving air is at a lower pressure than slow-moving air, so the pressure above the wing is lower than the pressure below. This creates the lift that powers the plane upward and this is how the takeoff is actually able to take place. (Source: REStARTS; pilotinstitute.com)