Does an aircraft need a longer runway to takeoff on airports that are at higher altitudes than sea level?

Yes, an aircraft needs a longer runway to take off on airports that are at higher altitudes than sea level. This is primarily due to the decrease in air density at higher altitudes.

Air density is the mass of air per unit volume. As altitude increases, the air becomes less dense, meaning there are fewer air molecules per unit volume. This reduction in air density affects the amount of lift that an aircraft's wings can generate.

Lift is the force that opposes gravity and keeps an aircraft in the air. It is generated by the difference in air pressure between the upper and lower surfaces of the wing. The higher the airspeed, the greater the lift. However, at higher altitudes, the lower air density means that the aircraft must fly faster to generate the same amount of lift. This requires a longer runway for the aircraft to reach the necessary takeoff speed.

In addition, the reduced air density at higher altitudes also affects the engine's performance. Engines produce less power at higher altitudes due to the lower oxygen content in the air. This means that the aircraft's engines must work harder to generate the necessary thrust for takeoff, which can further increase the runway length requirement.

The specific runway length required for takeoff at a given airport depends on various factors, including the aircraft's weight, engine power, and the airport's altitude and temperature. Airport operators take these factors into account when designing and maintaining runways to ensure safe takeoffs and landings.