Photographs by JarrahTree...commons.wikimedia.org / CC BY 2.5 AU

Temperature and altitude testing

Planes are brought to extremely hot/cold climates or very high/low altitudes to check that they function normally.

Velocity minimum unstick test

The minimum unstick speed test is considered as one of the most spectacular and the most difficult for pilots. Velocity minimum unstick or VMU is the jet’s airspeed at and above which the airplane can safely lift off the ground, continue the takeoff, and remain controllable.

Von Gyrostat (Wikimedia, CC-BY-SA 4.0), CC BY-SA 4.0

Before the test's implementation, the crew undergoes additional instructions. When gaining speed during the takeoff, the pilot scrapes a plane’s tail along the runway and carefully lifts the nose of the jet to the sky by 10 ° to determine the minimum speed needed for takeoff. As soon as the speed is determined, it is entered into the control instructions.

Brake testing

Maintaining the landing gear and brakes in order is critical to safety, as during landing the machine is exposed to high-level forces and shocks.

At brake tests, the plane is loaded at its maximum weight and equipped with worn-out brake pads. Then the machine is brought to takeoff speed on the runway before stopping. The wheels should deflate in the high heat, and emergency crews have to wait five minutes to see if the fire spreads to the plane’s body.

Unlike cars, crash tests are not carried out in the civil aviation industry. The only certification crash test of a passenger jet was carried out in December 1984 at Edwards Air Force Base, commissioned by the Federal Aviation Agency. However, the subject of certification in this case was not the aircraft, but the fuel in its tanks.

Operating tests

Even after the plane gets the green light from the regulators and starts commercial flight service, the machine and its engine continue to undergo regular checks and maintenance. Technicians dismantle, clean, and inspect the plane’s engine at regular intervals. They check the machine’s motor, replace the worn parts, reassemble, test it, and re-attach the engine back into the plane. Besides that, before every flight, the pilot or co-pilot in command conducts a visual inspection of the critical parts of the plane, like sensors, probes, structural components, and exposed motors and cables. The preflight check also includes running tests on various systems onboard the plane, such as fire detectors, weather radar, and warning lights.