What must a pilot ensure when flying through a Class B airspace?

When flying through Class B airspace, it is crucial for a pilot to obtain Air Traffic Control (ATC) clearance prior to entry. Class B airspace is designed to protect aircraft in busy terminal areas, typically surrounding major airports. This airspace frequently sees a high volume of air traffic, which can include a mix of commercial airliners and general aviation aircraft.

Obtaining ATC clearance ensures that the pilot is given explicit permission to enter this controlled airspace, which allows ATC to manage all traffic effectively and maintain safety. The requirement for clearance helps keep the flow of traffic organized and reduces the risk of midair collisions. This system enhances safety and efficiency in what can often be a congested airspace environment.

Other options, such as the idea that filing a flight plan is optional or maintaining VFR conditions at all times, do not align with the specific requirements for Class B airspace. In fact, while VFR pilots must avoid Class B airspace without clearance, it is not required for them to maintain VFR conditions if they are operating with clearance in that space.