Question ATPL - Airline Transport Pilot license - Air Law

100 - ATPL - An aircraft shall display, if so equipped, an anti-collision light:

While taxiing, but not when it is being towed

Outside the daylight-period in flight, but not on the ground when it is being towed

Outside the daylight-period at engine-start. During the daylight-period this is not applicable

On the ground when the engines are running