To prevent overheat damage to the wing leading edge, the engine bleed air is given maximum cooling during ground operations.
A Prior to ground operations, maximum cooling of the engine bleed air is provided to avoid the overheat damage to the wing leading edge.
B To keep the wing leading edge from overheat damage, the engine bleed air has a maximum cooling effect during ground operations.
C while the aircraft is operating on the ground, the engine bleed air provides a best cooling to the wing leading edge to renovate the damage due to overheat.