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Aviation: Automatic Directional Finding Equipment

Volume 686: debated on Tuesday 7 November 2006

asked Her Majesty's Government:

Why Schedule 5 to the Air Navigation Order 2005 (SI 2005/1970) requires automatic directional finding equipment to be fitted in aircraft flying in airways within United Kingdom airspace.[HL8085]

The Air Navigation Order 2005 details the equipment carriage requirements for aircraft to navigate safely in UK airspace below flight level (FL) 95 (9500 feet), without the need for air traffic controllers to provide navigational assistance.

The UK Air Traffic Services (ATS) route structure is a complex system of airways and upper ATS routes enabling operators to flight-plan and safely fly en route under instrument flight rules (IRF) through UK airspace.

Above FL95 the ATS route structure is based on area navigation (RNAV) whereby aircraft can navigate without having to fly from one ground-based navigation beacon to the next. Below FL95 the ATS structure is predominantly based on conventional navigation, which requires the fitment of ADF equipment in aircraft to safely navigate between ground-based beacons.

asked Her Majesty's Government:

How many automatic direction-finding waypoints are required for the airways of the United Kingdom airspace above flight level 100; and [HL8117]

How many global positioning system RNAV MNP5 waypoints are required for the airwaysof the United Kingdom airspace above flightlevel 100.[HL8118]

I refer the noble Lord to the Answer I have given today (HL 8085).

Above flight level (FL) 95 (9,500 feet) basic area navigation (BRNAV) rules apply and no automatic direction finding (ADF) waypoints are technically required. However, ADF information may form part of the navigation solution, dependent upon its availability.

The UK's RNAV waypoints are set out in the en route section of the UK Aeronautical Information Publication (AIP), pages 4-3-1 to 4-3-15, with five-letter designator codes identifying individual navigation waypoints. The AIP is available free of charge from the UK Aeronautical Information Service (AIS) website at The AIP information does not differentiate between waypoints at particular flight levels.