State of Registry vs State of Operator

Definitions and Key Differences

• State of Registry: This is the nation that maintains the aircraft’s entry on its civil aircraft register. It assigns nationality and registration marks, issues the Certificate of Airworthiness, and is ultimately responsible for ensuring the aircraft meets continuing airworthiness standards. The State of Registry also handles regulatory matters like registration transfer and must notify the State of Design when a new type is registered.

• State of Operator: This refers to the country where the operator (the airline or company flying the aircraft) has its principal place of business or, if none, its domicile. The State of Operator is responsible for operational oversight, including the approval and surveillance of air operator certificates, and ensuring that operators comply with security and operational requirements.

Practical Implications

• The State of Registry determines the aircraft’s legal nationality and is responsible for technical compliance, airworthiness, and registration matters.
• The State of Operator oversees operational aspects, such as crew licensing, operator certification, and compliance with local aviation security and safety programs.
• For international operations, an aircraft must comply with the laws of the State it is flying over, regardless of its registry or operator.
• Dual registration (registering an aircraft in more than one State) is not permitted under international law.

Example Scenario

An aircraft registered in France (State of Registry) but operated by a German airline (State of Operator) will have its airworthiness managed by France, while Germany oversees the airline’s operational practices and crew qualifications. Both States must coordinate to ensure full compliance with international and national regulations.