What are the speed requirements for the ATC assigned airspeed of 130 knots when descending on a published arrival route?

The correct answer pertains to the speed requirements established by the FAA for aircraft following published arrival routes when they are assigned an airspeed limit of 130 knots by Air Traffic Control (ATC). In this case, the minimum speed that an aircraft can legally fly while complying with the assigned airspeed would be set at 120 knots, which allows for safe maneuvering and descent, especially when considering factors like the aircraft's response to changes in throttle and flap configurations.

While the upper limit is established as 140 knots, it's important to ensure that the aircraft is not flying too fast below its maximum allowable speed for the descent phase. This range (120-140 knots) accommodates normal operational safety without risking excessive speeds that could complicate aircraft control during descents and approaches. This understanding comes from the FAA's guidelines, which are designed to enhance safety during specific phases of flight.

In summary, the option stating 120-140 knots aligns with the standard airspeed tolerance given for aircraft that have been assigned a target speed of 130 knots during their descent on an arrival route, ensuring that pilots can operate efficiently within the parameters for safe approach and landing preparation.