Why has it been unclear whether the 1952 Rome Convention covers damage caused by sonic booms?

The 1952 Rome Convention, which governs surface damage caused by foreign aircraft, contains a provision in Article 1(1) that excludes the right to compensation if the damage results from the "mere fact of passage of the aircraft through the airspace in conformity with existing air traffic regulations."1

This language creates ambiguity regarding sonic booms because it is unclear whether the shock waves produced by supersonic flight—which can cause significant damage like glass breakage—constitute a "mere fact of passage" when the aircraft is otherwise operating in compliance with air traffic rules. Because the convention does not explicitly clarify whether the physical impact of a sonic boom is an inherent, protected aspect of flight or a compensable form of surface damage, its application to such incidents remains a subject of legal doubt.21