4.3 Limitations to the Approval of Equipment 4.3.1 It is necessary, besides establishing total system performance, to take into account the limitation of particular types of navigation and altimetry systems. The need is to ensure that in the event of partial system failure, the remaining equipment is sufficient to enable the aircraft to operate in accordance with the conditions of its original or amended clearance. To assist in meeting this requirement, the necessary equipment to be available and serviceable at entry into the airspace concerned, must be specified. 4.3.2 To simplify regulatory procedures, States may wish to establish performance criteria for routes and/or geographical areas on a worldwide basis. Such an approach will obviate the need for detailed negotiations on each occasion that an Operator may wish to extend its route approvals. In exercising such options, it will be for the States concerned to ensure that Regional specifications of performance are met and that, in cases where no specific requirements have been established, at least the minimum conditions laid down in Part 1, are taken into account.
