air overpressure

Resistance to air overpressure.

If the Valsalva maneuver is conducted during ascent, residual air overpressure in the middle-ear can potentially be released through the Eustachian tubes.

On MiG-21 this movement also makes the opening between the intake (diffusor) lip and the cone smaller, preventing the inside of the intake section from bursting open from dynamic air overpressure at the aircraft's highest speeds above Mach 2.