Guidance concerning Air Navigation in and above the NAT MNPSA
with at least two fully serviceable Long Range Navigation Systems (LRNSs). A LRNS may be one of the following:
one Inertial Navigation System (INS);
one Global Navigation Satellite System (GNSS); or
one navigation system using the inputs from one or more Inertial Reference System (IRS)
or any other sensor system complying with the MNPS requirement.
Note 1: Currently the only GNSS system fully operational and for which approval material is available, is GPS.
A GPS installation must be approved as follows: If the two required LRNSs are both GPS, they must be with FAA Advisory Circular AC-20-138A Appendix 1 and
approved in accordance their operation approved (previously FAA Notice
8110.60) function. need not
requires that GPS systems used in Oceanic airspace must have a FDE Equipment which previously demonstrated compliance with N8110.60 be re-evaluated. States other than the USA may set their own standards
for operational approval of GPS to provide Oceanic and remote areas but in all cases requirement to carry out Pre-Departure Programmes (See Chapter 8 - GNSS (GPS)
Primary Means of Navigation in these approvals will include the
GPS serves as only one of the two required LRNSs, then it must be in accordance with FAA TSO-C129 or later standard as Class A1, A2,
instance individual States vary in their insistence upon the need for the conduct pre-departure satellite navigation prediction programmes (viz.FDE RAIM).
Currently equivalent approval material for GLONASS is not under development but it will need to be available prior to approval of any GLONASS equipped aircraft for MNPS operations.
each LRNS must be capable of providing to the flight crew a continuous indication of the aircraft position relative to desired track.
it is also highly desirable that the navigation system employed for the provision of steering guidance is capable of being coupled to the autopilot.
Some aircraft may carry two independent LRNS but only one FMCS. Such an arrangement may meet track keeping parameters but does not provide the required redundancy (in terms of continuous indication of position relative to track or of automatic steering guidance) should the FMCS fail; therefore, in order to obtain MNPS certification, dual FMCS is required to be carried. For example: a single INS is considered to be one LRNS; and an FMCS with inputs from one or more IRS/ISS is also considered to be a single LRNS.
It is important that navigation data provided to crews in the form of charts, flight plans,
master documents, track messages, etc. are presented in a format suitable for error-free use in the cockpit environment. A significant proportion of navigation errors result from the use of incorrect or misinterpreted
NAT Doc 007