Turbine Blade Clearance.

Creep is term used to describe the continuous and permanent stretching of turbine blades due to high temperatures and centrifugal forces acting on the blades. Each time a turbine is heated, rotated then stopped (referred to as an engine cycle) each blade will be slightly longer. At regular interval, specified intervals the AME will carry out a turbine tip clearance check. The AMM will stipulate what limitations must be observed and if these are exceeded then the engine or module will require replacing.