What is the minimum horizontal separation needed for a B757 on parallel runways to be considered as using the same runway?

The minimum horizontal separation for a Boeing 757 on parallel runways to be considered as using the same runway is 700 feet. This requirement is determined by safety regulations established by aviation authorities, which take into account the aircraft's dimensions and the potential for wake turbulence.

Regarding parallel runways, if two aircraft are operating simultaneously, maintaining this specific distance ensures that the safety margins are adequate to account for the wake turbulence generated by the larger aircraft, in this case, the B757. Adequate separation is essential to protect aircraft from potential hazards, allowing for safe operations during departures and arrivals while on parallel runways.

This 700 feet standard is in contrast to the other separation distances suggested in the options, which either provide insufficient buffer for the safety of operations involving the B757 or exceed the necessary space without reason, as the designated minimum effectively addresses safety while optimizing runway usage.