[bongodriver]

You are only allowed to fly an aircraft the instructor has authorised you to because technically you will be flying on the instructors license.

Another point to note is that the first solo sessions will only release you into the circuit for take off and landing practice, you won't be released to do any form of cross country or local area flying until you have done dual sessions dealing with navigation and practice forced landings, some instructors may even like to touch on some basic instrument flying too just to cover all bases, it can be an anxious time for us instructors sending students off solo, so we like to know everything has been covered.