Definition

A level bust is defined by EUROCONTROL as: Any unauthorised vertical deviation of more than 300 feet from an ATC flight clearance.

Description

A level bust occurs when an aircraft fails to fly at the level to which it has been cleared, regardless of whether actual loss of separation from other aircraft or the ground results. Level busts are also known as Altitude Deviations.

For further information read the lead article about Level Bust.