Airplanes and birds

Airplanes, birds. Are there any similarities and difference? Yes! Lets take a look! But first, lets us talk about airplanes. Airplanes Question: HOW DO PLANES FLY? Four forces act on an aeroplane when its flying. 1) Lift: is an upward force that holds an aeroplane in the air. 2) Thrust: is the force that moves the aeroplane forward. 3) Drag: is air resistance that holds the aeroplane back. 4) Weight: is the force that pulls the aeroplane down. The wings of an aeroplane are a a special shape, called an aerofoil. The top of the wing is straight.