Pilots may fly across the North Atlantic within MNPS Airspace (FL 285 - FL 420) or at flight levels designated as RVSM Airspace, only if they are in possession of the appropriate Approval(s) issued by the State of Registry or the State of the Operator.

GENERAL

It is implicit in the concept of MNPS that all flights within the airspace achieve the highest standards of horizontal and vertical navigation performance and accuracy. Formal monitoring programme are undertaken to quantify the achieved performances and to compare them with established Target Levels of Safety (TLS).

Aircraft operating within MNPS Airspace are required to meet a Minimum Navigation Performance Specification (MNPS) in the horizontal plane through the mandatory carriage and use of a specified level of navigation equipment which has been approved by the State of Registry, or State of the Operator, for the purpose. Such approvals encompass all aspects affecting the expected navigation performance of the aircraft. The requirements are set out in ICAO NAT Doc 001, T13.5N, ‘Consolidated Guidance Material North Atlantic Region’.

With the introduction of RVSM, aircraft intending to operate at RVSM levels in NAT MNPS Airspace are additionally required to be equipped with altimetry and height keeping systems which meet RVSM Minimum Aircraft System Performance Specifications (MASPS). RVSM MASPS are contained in designated FAA document, 91-RVSM, and JAA document, TGL6 (Temporary Guidance Leaflet No. 6).

NAT Doc 001 is maintained by the ICAO European and North Atlantic Office (Paris) and is provided, together with the RVSM MASPS documents, to assist States of Registry, operators, owners and planning staff who are responsible for issuing or obtaining MNPS/RVSM approvals for aircraft. However, the ultimate responsibility for checking that a NAT MNPS/RVSM flight has the necessary approval(s) rests with the pilot in command. In the case of most regular scheduled flights this check is a matter of simple routine but pilots of special charter flights, private flights, ferry and delivery flights are advised to pay particular attention to this matter. Routine monitoring of NAT traffic regularly reveals examples of pilots of non-approved flights from within these user groups flight planning or requesting clearance within MNPS Airspace or at RVSM levels. All such instances are prejudicial to safety and are referred to relevant State Authorities for further action.

While not a specific element of NAT MNPS approval, pilots and operators are reminded that for flights over the NAT, ICAO SARPS Annex 6, Part 1, Chapter 6, requires carriage of Emergency Locator Transmitters (ELTs). It should be further noted that new specifications for these beacons to operate exclusively on frequency 406 MHz (but with a 121.5 MHz search and rescue homing capability) will apply from 2005 although new aircraft will need to be so equipped from 2002.

APPROVAL

Approval for MNPS operations will require the checking by the State of Registry or State of the Operator, of various aspects affecting navigation performance. These aspects include: the navigation equipment used, together with its installation and maintenance procedures; plus the crew navigation procedures employed and the training requirements.

Approval to operate at RVSM levels within MNPS Airspace is subject to additional requirements regarding aircraft height keeping performance in accordance with the MASPS. Each aircraft intended to be flown in RVSM airspace must have State Airworthiness Approval and crews/operators must be specifically State approved for RVSM operations.

NAVIGATION REQUIREMENTS FOR UNRESTRICTED MNPS AIRSPACE OPERATIONS

Longitudinal Navigation

Longitudinal separations between subsequent aircraft following the same track (in-trail) and between aircraft on intersecting tracks in the NAT MNPS Airspace are assessed in terms of differences in ATAs/ETAs at common waypoints. The longitudinal separation minima currently used in the NAT MNPS Airspace are thus expressed in clock minutes. The maintenance of in-trail separations is aided by the application of the Mach Number Technique (See Chapter 8). However, aircraft clock errors resulting in waypoint ATA report errors can lead to an erosion of actual longitudinal separations between aircraft. It is thus vitally important that the time-keeping device intended to be used to indicate waypoint passing times is accurate, and is synchronized to an acceptable UTC time signal before commencing flight in MNPS Airspace. In many modern aircraft, the Master Clock can only be reset while the aircraft is on the ground. Thus the pre-flight procedures for any NAT MNPS operation must include a UTC time check and resynchronization of the aircraft Master Clock. Lists of acceptable time sources for this purpose have been promulgated by NAT ATS Provider States. A non-exhaustive list is shown in Chapter 9 of this Document.
 

Lateral Navigation

There are two navigational requirements for aircraft planning to operate in MNPS Airspace. One refers to the navigation performance which should be achieved, in terms of accuracy. The second refers to the need to carry standby equipment with comparable performance characteristics (ICAO Annex 6, Parts I and II, Chapter 7 refer). Thus in order to justify consideration for State approval of unrestricted operation in the MNPS Airspace an aircraft must be equipped with the following:

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.

Each LRNS must be capable of providing to the flight crew a continuous indication of the aircraft position relative to desired track.

It is highly desirable that the navigation system employed for the provision of steering guidance is capable of being coupled to the autopilot.

ROUTES FOR USE BY AIRCRAFT NOT EQUIPPED WITH TWO LRNSs

Routes for Aircraft with Only One LRNS

A number of special routes have been developed for aircraft equipped with only one LRNS* and carrying normal short-range navigation equipment (VOR, DME, ADF). It should be recognized that these routes are within MNPS Airspace, and that State approval must be obtained prior to flying along them. These routes are also available for interim use by aircraft normally approved for unrestricted MNPS operations that have suffered a partial loss of navigation capability and have only a single remaining functional LRNS. Detailed descriptions of the special routes known as ‘Blue Spruce Routes’ are included in Chapter 11 of this Document.
 

Routes for Aircraft with Short-Range Navigation Equipment Only

Aircraft which are equipped only with short-range navigation equipment (VOR, DME, ADF) may operate through MNPS Airspace, along routes G3 or G11, but again State approval is required. (See Chapter 11 for details of these routes.)

It is the responsibility of pilots with limited certification to reject clearances which would otherwise divert them from officially permitted routes.
 

SPECIAL ARRANGEMENTS FOR THE PENETRATION OF MNPS AIRSPACE BY NON-MNPS APPROVED AIRCRAFT

Aircraft not approved for operation in MNPS Airspace may be cleared by the responsible ATC unit to climb or descend through MNPS Airspace provided:

• the climb or descent can be completed within the coverage of selected VOR/DMEs or NDBs (see AIP Iceland) and/or within radar coverage of the ATC unit issuing such clearance and the aircraft is able to maintain Direct Controller/Pilot Communications (DCPC) on VHF; and
• MNPS approved aircraft operating in that part of the MNPS Airspace affected by such climbs or descents are not penalized.

Non-MNPS Approved aircraft may also be cleared to climb or descend through MNPS Airspace for the sole purpose of landing at or departing from an airport which underlies MNPS Airspace but which does not have serviceable short range navaids, radar or DCPC. Details of the required provisions will be found in the AIS publications of the appropriate ATS Provider State.
 

EQUIPMENT REQUIRED FOR OPERATIONS AT RVSM LEVELS

The minimum equipment standard is embodied in the MASPS for RVSM flight operations. These MASPS require:

• two fully serviceable independent primary altitude measurement systems;
• one automatic altitude-control system; and
• one altitude-alerting device.

The flight control and air data measurement systems of many modern commercial aircraft are designed to provide multiple redundancy. Nevertheless, the Minimum Equipment List (MEL) for RVSM operations must reflect the foregoing minimum requirements. In particular it must be noted that if following a failure of an Air Data Computer (ADC), both the Captain’s and Co-pilot’s altimeter instruments are connected to a remaining single functional ADC, this arrangement does not meet the RVSM MASPS requirement for two independent primary altimetry systems.

Airworthiness Approval for RVSM operations may be granted by the appropriate State Authority to individual aircraft, or to a group of aircraft which are nominally identical in aerodynamic design and in items of equipment contributing to height keeping accuracy.

When checking altimeters (pre-flight or in-flight), confirmation is necessary that all altitude indications are within the tolerances specified in the aircraft operating manual. At least two primary altimeters must at all times agree within plus or minus 200 feet.
 

SPECIAL ARRANGEMENTS FOR NON-RVSM APPROVED AIRCRAFT TO:

Climb/Descend Through RVSM Levels

MNPS approved aircraft that are not approved for RVSM operation will be permitted, subject to traffic, to climb/descend through RVSM levels in order to attain cruising levels above or below RVSM airspace. Flights should climb/descend continuously through the RVSM levels without stopping at any intermediate level and should "Report leaving" current level and "Report reaching" cleared level.

Operate at RVSM Levels

ATC may provide an altitude reservation for an MNPS approved aircraft that is not approved for RVSM operation to fly at RVSM levels provided that the aircraft:

• is on a delivery flight; or
• was RVSM approved but has suffered an equipment failure and is being returned to its base for repair and/or re-approval; or
• is on a mercy or humanitarian flight.

Operators requiring such an altitude reservation should contact the initial Oceanic Area Control Centre (OAC), normally not more than 12 hours and not less than 4 hours prior to the intended departure time. The altitude reservation approval should be clearly indicated in Item 18 of the ICAO flight plan. It must be noted that the provision of this service is intended exclusively for the purposes indicated above and is not a means for an operator or pilot to circumvent the RVSM approval process. The service will not be provided to aircraft that are not approved for MNPS operations.

PERFORMANCE MONITORING

The horizontal (i.e. latitudinal and longitudinal) and vertical navigation performance of operators within NAT MNPS Airspace is monitored on a continual basis. If a deviation is identified, follow-up action after flight is taken, both with the operator and the State of Registry of the aircraft involved, to establish the cause of the deviation and to confirm the approval of the flight to operate in NAT MNPS and/or RVSM Airspace. The overall navigation performance of all aircraft in the MNPS Airspace is compared to the standards established for the Region, to ensure that the relevant TLSs are being maintained. (See Chapters 9 & 10.)

ABBREVIATIONS

(C) HANKE-Aviation GmbH 2014