2021-05-20 - MATS Part 1 (9th Edition) Summary

[Chad Byworth]

Effective 20 May 2021

The 9th Edition of MATS Part 1 becomes effective on the above date. It includes changes in the following areas, incorporating some recent supplemental instructions to MATS 1:

• Vectoring to Final Approach
• RNP Approaches
• Wake Turbulence
• VMC Criteria in Class D Airspace

These changes will become effective on VATSIM on the above date and are summarised below, however controllers are encouraged to review the relevant sections of MATS Part 1 (9th Edition). Comments in [square brackets] highlight the differences against the 8th Edition.

Vectoring to Final Approach

There are minor changes to vectoring restrictions for ILS/VOR/NDB/surveillance radar approaches (see below for RNP) however, the day-to-day impact for most units is nil. 

When vectoring to final approach controllers shall apply the following restrictions:

• Except when requested by the pilot, or authorised by a vMATS Part 2, aircraft shall be vectored to establish the final approach track no closer than 2NM before the FAF for an ILS/VOR/NDB/surveillance radar approach (see below for RNP) - [this changes from the previous restriction of no closer than 5NM from touchdown]
• At units where CDA procedures are not used controllers shall position aircraft to facilitate a period of level flight at either the published FAF procedure altitude or, where approved in the vMATS Part 2 and ATCSMAC allows, a level below the FAF procedure altitude - [no previous restriction specified]
• Allocate closing headings of not greater than 45° offset from the final approach track (not greater than 30° for independent parallel approaches) - [this changes from a previous recommendation to use less than 40°]

Note: All UK aerodromes shall be considered notified for vectoring to establish closer than 2NM from the FAF or, where the ATCSMAC allows, below the published FAF procedure altitude unless documented otherwise in a vMATS Part 2 or ACB.

RNP Approaches

These changes are notified as changes to ‘Vectoring to Final Approach’ within the MATS Part 1 Revision History however, unlike the above changes these are more significant and will impact on how controllers vector to RNP approaches from 20 May 2021 onwards.

When vectoring for an RNP approach controllers shall apply the following restrictions:

• When traffic permits controllers should permit aircraft to route on own-navigation via the appropriate IAF not below the published procedure altitude
• When necessary, controllers may vector onto the final approach track but must:
  • Allocate closing headings of not greater than 45° offset from the final approach track (not greater than 30° for independent parallel approaches)
  • Position aircraft to establish on the final approach track no later than the IF
• Controllers should not position aircraft on to the final approach track inside the IF as this may prevent aircraft RNP equipment from correctly flying the approach

[Previously controllers were permitted to vector aircraft onto the final approach track of an RNP approach so long as the aircraft was established prior to the FAF. For some aircraft this may prevent the approach from correctly sequencing within the avionics equipment, preventing the pilot from flying the approach, hence the above restrictions]

Note: Due to restrictions relating to controlled airspace containment, controllers at the following aerodromes may continue to vector aircraft to establish inside the IF so long as the pilot is informed and the aircraft establishes the final approach track prior to 2NM from the FAF:

• Stansted - EGSS
• Liverpool - EGGP
• Bristol - EGGD - for Runway 09 approach only

Wake Turbulence Separation

The following changes are made to the wake turbulence separation criteria:

• Guidance on application of wake turbulence separation criteria for tilt rotor types
• A380 category replaced with SUPER category - A380/AN124/AN225 types
• SUPER leading - HEAVY following separation now 5NM [reduced from 6NM]
• Opposite direction departures:
  • SUPER leading - LIGHT/SMALL/MEDIUM following separation now 4 min [increased from 3 min]
  • SUPER leading - HEAVY following new separation standard 3 min [no previous separation requirement]

Note: There is change to wake turbulence separation for same direction departures.

VMC Criteria in Class D Airspace

Following the UK’s exit from the EU the historical Class D VMC criteria have been reintroduced. These considerably simplify VFR operations in Class D airspace and will reduce the need for SVFR clearances when the cloud ceiling is below 1500ft AGL.

The following conditions, during the day, are now considered VMC thus permitting VFR flight:

• For aircraft other than helicopters, flying at or below 3000ft AMSL or 1000ft AGL (whichever is the higher) at 140 kts IAS or less - clear of cloud and with the surface in sight, and with a visibility of 5 km 
• For helicopters, flying at or below 3000ft AMSL or 1000ft AGL (whichever is the higher) at 140 kts IAS or less - clear of cloud and with the surface in sight, and with a visibility of 1500m

For VFR traffic departing/arriving at an aerodrome or transiting the ATZ the more stringent criteria of remaining clear of cloud by 1000ft vertically/1.5 km horizontally with a visibility of 5 km (8 km above FL100) remains. When conditions are such that the cloud ceiling is less than 1500ft AGL, controllers should advise the pilot and ask them to report their intentions. The pilot may then proceed either by means of a SVFR clearance or, if their simulator is set to VMC, by VFR clearance. In the event of a pilot simulating VMC when IMC prevails the controller may either ensure standard separation against other flights (effectively treating the flight as SVFR for controlling purposes) or obtain positive confirmation from the pilot that they have conflicting traffic in sight when any instruction would require visual manoeuvring (for example a turn to final behind an IFR inbound).

Note: For traffic operating at or above 3000 ft AMSL/1000 ft AGL/140 kts IAS the previous Class D VMC criteria of remaining clear of cloud by 1000ft vertically/1.5 km horizontally with a visibility of 5 km (8 km above FL100) remains.

Documentation Status

Except where stated above, these changes override any conflicting vMATS Part 2 procedures published prior to 20 May 2021. For vMATS Part 2 procedures published on or after 20 May 2021 which deviate from MATS Part 1 (9th Edition) controllers should use the documented vMATS Part 2 procedures which will have been developed with these MATS Part 1 changes in mind.