PART 4 4. AIRCRAFT APPROVAL PROCESS 4.1 State Responsibility 4.1.1 It is implicit in the concepts of MNPS and RVSM that all operations within each designated airspace achieve the highest standards of navigational performance accuracy. All flights within NAT MNPS Airspace must have the approval of either the State of Registry of the aircraft, or the State of the Operator. Aircraft operating in RVSM Airspace are required to be compliant with the altimetry minimum aircraft performance specification (MASPS) and hold an issued approval. Such approvals encompass all aspects of the expected navigation and height-keeping performance accuracy of the aircraft, including that covering the equipment carried, the installation and maintenance procedures, crew navigation procedures and training. 4.1.2 RVSM approval for operation in the NAT must include authority to operate in MNPS Airspace. However, an MNPS approval only, authorises an Operator to fly at those flight levels in MNPS Airspace that are not designated for the use of RVSM operations. From circa January 2002, RVSM approval will apply throughout the entire NAT Region. When this happens then an RVSM approval will not necessarily include an MNPS approval, unless an Operator wishes to fly within