Book 23, Question 9
Why Do Planes Need to Go Fast Before They Can Take Off?
A plane cannot just jump into the sky. It has to roll down the runway first. It needs to get going fast! A big jet may use more than two miles of runway on a hot, heavy day.
More fun facts
- During the takeoff roll, a plane speeds up from a standstill until its wings make enough lift to carry it into the air.
- Near the ground, up to about one wingspan high, a wing has less drag, which helps a plane just after it lifts off.
- Pilots take off into the wind when they can, because a headwind gives the wings some airspeed before the plane even starts rolling.
- With a headwind, the plane needs less ground speed to fly, so it can use a shorter runway.
- Pulling a plane into the air before it reaches flying speed can make the wing tilt too much and settle back onto the runway, or even stall.
- In strong, gusty wind, pilots stay on the ground a little longer to build extra speed before lifting off.
- Thin air at hot or high airports weakens the engine and propeller, so takeoff rolls get longer.
Sources: faa.gov
Questions kids ask
What is rotation?
It is the moment the pilot raises the nose to tilt the wings up more, so they lift the plane off the ground.