NATS is planning to utilise the precision area navigation (P-RNAV) capabilities of aircraft across the breadth of its operations to help meet operators' demands for airspace while, at the same time, minimising the impact on the environment of the anticipated increase in the number of flights. While Basic RNAV (B-RNAV) has been mandated for en-route operations above FL 95 in UK controlled airspace since 1997, the use of P-RNAV has, thus far, been limited to trials.
However, under a proposed airspace change, NATS is seeking to introduce a large number of procedures predicated on the use of P-RNAV, and associated functionality such as VNAV. The proposal will affect operations to and from all the London airports (except Gatwick), as well as Northolt, in a region of airspace known as Terminal Airspace North (TCN). In the event that the proposal is accepted by the CAA, the changes could be implemented from March 2009.
The impact of the proposed implementation will be that to fly the P-RNAV procedures, operators will need to be in possession of an operational approval issued by the appropriate State regulatory authority. For UK operators, this is the UK CAA's Safety Regulation Group. While provision will be made for those operators not holding operational approval, these operations could be subject to departure delays and longer routings.
More details regarding the impact of the proposed implementation can be found in "Important information regarding P-RNAV approvals and safety issues associated with a proposed airspace change in the London Terminal Control Area"
