Part 129 of the US Federal Aviation Administration's regulations covers the "operations of foreign air carriers and foreign operators of US-registered aircraft engaged in common carriage" in the USA.
Section 11 outlines the operations specifications (Ops Specs). These state which airports and aircraft types can be used, and routes flown, as well as compulsory training requirements for pilots operating at US airports with specific navigational practices. Airlines have to complete "hundreds of documents" for each aircraft destined for US skies, which can take up to 120 days, says the Association of European Airlines. These dossiers contain information already in airlines' air operator's certificates (AOC) and require no extra physical inspection. Other countries with additional operating requirements for foreign carriers use national AOCs for basic data, with processing time usually seven to 14 days.
Source: Flight International