What is required for a student to operate an aircraft solo within Class B airspace?

To operate an aircraft solo within Class B airspace, it is essential for a student pilot to have a logbook endorsement showing that they have received both ground and flight training specifically for that airspace. This requirement ensures that the student pilot is aware of the unique operational procedures, communication protocols, and other regulatory considerations that pertain to Class B airspace, which is typically found around busy airports. The endorsement demonstrates that the student has the necessary knowledge and skills to safely operate in that environment, including understanding air traffic control instructions and navigation techniques that may be required.

The other options do not meet the requirements for solo operations in Class B airspace. A valid pilot's license, while necessary for licensed pilots, does not apply to student pilots who must still receive specific endorsements. Completion of a written exam is not a condition for solo endorsements in terms of airspace. Lastly, there is no minimum hour requirement specified for solo training that is universally applicable; rather, the focus is on adequate training specifically related to the complexities of operating in Class B airspace.