. Takeoff and Landing

akeoff and landing are the maneu­vers that aircraft or spacecraft per­form to launch into flight and then return to the ground. They are potentially the most hazardous part of a journey in the air or in space.

Airplane Takeoff

Whether an airplane is a small, single­engine light aircraft or the biggest air­liner, the process of taking off is much the same. The crew goes through a checklist to ensure that all switches and other controls are in the right positions for takeoff. Flaps and leading-edge slats are deployed to produce more lift for takeoff. The aircraft taxis out to the end
of the runway. When it is cleared for takeoff, the engine power levers are pushed forward, the brakes are released, and the takeoff run begins.

A typical takeoff speed for a small plane is about 65 miles per hour (105 kilometers per hour). A large airliner takes off at about 140-190 miles per hour (225-305 kilometers per hour). The actual speed depends on the aircraft type, its weight, and the weather condi­tions. As an airliner accelerates along a runway, it reaches a speed called V1. Beyond this point, there is not enough runway left for the plane to stop safely,
so it must take off. The aircraft then reaches VR-the speed at which the pilot raises the plane’s nose and takes off. The plane lifts off and continues to acceler­ate. The next significant speed is V2, the minimum speed the plane must reach to climb away from the ground safely. The normal climb-out speed is a little higher than V2.

Gliders have no power of their own to get off the ground, so they are usual­ly towed into the air. One end of a cable is attached to the glider’s nose. The other end is attached to an airplane, and the glider is towed until its wings generate enough lift to fly. The pilot drops the cable by pulling a lever in the cockpit, and the glider soars away.