Which of the following documents is NOT required by every aircraft of a contracting State engaged in international navigation?

In the context of international aviation regulations, particularly those governed by organizations such as the International Civil Aviation Organization (ICAO), certain documents are mandated for aircraft engaged in international navigation to ensure safety, accountability, and compliance with international standards.

The certificate of registration is essential as it provides official proof of ownership and indicates that the aircraft is recognized by its country of registration. Appropriate licenses for each member of the crew are also required to ensure that individuals operating the aircraft possess the necessary qualifications and training, which is critical for safety in international aviation.

The journey log book serves an important role as it tracks the details of flights, including routes, durations, and any incidents that may occur. This documentation is crucial for regulatory oversight and for maintaining the safety and security of air travel.

However, a maintenance log book, while useful for recording the history of aircraft maintenance and repairs, is not universally mandated for every aircraft utilized in international navigation by contracting States. The requirement for a maintenance log book can vary by country and may not be enforced as stringently as the aforementioned documents. This allows for greater flexibility regarding maintenance documentation as long as other regulatory requirements are met. Thus, the maintenance log book is the correct choice as it is not a universally required document for all aircraft under international