ATPL Study Guide 2026

FAA and ICAO both require pilots to always read back taxi instructions, runway crossing clearances, and hold-short instructions to verify understanding and prevent runway incursions.

As Mach number increases into the transonic range, shock wave formation causes a rearward migration of the center of pressure, generating a strong nose-down pitching moment.

Bernoulli's principle states that as fluid velocity increases, static pressure decreases, creating the pressure differential across the wing that generates lift.

A temperature inversion is a layer of the atmosphere where temperature increases with altitude rather than the normal decrease, trapping pollutants and moisture below.

Load factor n = Lift / Weight and represents the number of 'g's the structure experiences; in straight-and-level unaccelerated flight n = 1.0.

The Auxiliary Power Unit (APU) is a small turbine engine located in the tail section of most large aircraft. Its primary function is to generate electrical power for the aircraft's systems when the main engines are shut down, and to provide bleed air for starting the main engines and for cabin air conditioning and pressurization. This allows the aircraft to operate independently of ground power units and air carts, enhancing operational flexibility.