Which of the following actions is prohibited during aircraft towing?

Exceeding speed limits during aircraft towing is prohibited primarily because maintaining a safe and controlled speed is crucial for the safety of both the towing vehicle and the aircraft. The towing process requires precision and careful handling, as aircraft are large and can be difficult to maneuver. Speeding can lead to a loss of control, potentially resulting in accidents or collisions on the airport taxiways or ramps, where other vehicles and personnel may be present.

In this context, other actions such as using high beams, communicating via radio, and performing visual checks are often necessary and can be part of maintaining safety during towing operations. High beams may be inappropriate in certain situations, but proper communication and visual checks are essential for coordinating safely with ground personnel and ensuring that the towing process is executed correctly.