The following documents shall be present on board the aircraft prior to its return to service, EXCEPT:

The documents that are required before an aircraft can be returned to service play a crucial role in ensuring compliance with aviation regulations and safety standards. The Certificate of Airworthiness (C of A), Certificate of Registration (C of R), and Radio Station License are all essential documents that confirm different aspects of an aircraft's legality, safety, and operational capability.

The Certificate of Airworthiness is a crucial document that certifies an aircraft is fit for flight. The Certificate of Registration indicates that the aircraft is registered with the appropriate aviation authority and is thereby legally recognized. The Radio Station License is also important, as it ensures that the aircraft can communicate in compliance with aviation communication regulations.

In contrast, the Aircraft Maintenance Checksheet is primarily an internal document used by maintenance crews during the servicing of the aircraft. While it is useful for ensuring that all required maintenance tasks have been completed, it is not a regulatory document that needs to be presented for the aircraft to be legally cleared for service. Therefore, while all other documents listed are necessary for compliance, the Aircraft Maintenance Checksheet does not need to be present for the aircraft's return to service.