What does a series of green flashes indicate while on the ground?

A series of green flashes while on the ground indicates that an aircraft is cleared to taxi. This signal is part of the air traffic control system, where specific light signals are communicated to pilots to ensure safe and efficient movement on the airport surface.

The use of green flashes is standardized, allowing pilots to identify their clearance and take appropriate actions. This is fundamental for maintaining safety and orderly progression at busy airports where multiple aircraft may be taxiing simultaneously.

In this context, the other options represent different stages of flight or other actions that do not involve a ground movement clearance. For example, landing clearance and takeoff clearance would involve different signals, often white or steady green, which are distinct from the flashing green specifically associated with taxiing. Understanding the meaning of these signals is crucial for pilots to comply with air traffic regulations and facilitate smooth airport operations.