What two conditions must be satisfied before an aircraft can operate IFR in controlled airspace?

For an aircraft to operate under Instrument Flight Rules (IFR) in controlled airspace, it is crucial to file an IFR flight plan and receive an appropriate clearance from Air Traffic Control (ATC). Filing an IFR flight plan is essential as it provides ATC with the necessary information to manage air traffic and ensure safety. It includes details about the flight route, altitude, and estimated times, which are vital for air traffic management.

Receiving ATC clearance is equally important because it validates the flight plan and authorizes the pilot to enter controlled airspace under IFR. Clearance ensures that the aircraft's operation is coordinated with other air traffic and complies with specific procedures, thereby maintaining safe and efficient airspace use. This two-step process is a fundamental requirement for IFR operations, ensuring that both the aircraft and the air traffic environment are prepared and aware of each other’s intentions.

In contrast with the other options, conditions such as pre-flight checks alone, obtaining pilot certification, or flying under VFR regulations do not encompass the necessary steps for IFR operations in controlled airspace. Operating under VFR does not satisfy IFR requirements, and similarly, weather clearance does not replace the need for an IFR flight plan or ATC clearance.