FINAL REPORT - Stakeholders - Ofcom

Some military GAT operations may still require conventional infrastructure support
beyond the 2010 limit foreseen by EUROCONTROL for the phasing out of VORs.
The UK is likely to make a decision regarding the future deployment of VORs in the near
future – it is recognised by the CAA that there may be redundancy in the current system,
with VOR/DME providing the same function and GNSS coming on-line.
3.4.4.5 L-Band DME
DME, as part of RNAV operations, is likely to be the primary means of navigation in the
short term. After 2006 (EGNOS introduction), they are likely to be used as the main
secondary navigation aid (providing redundancy for GNSS). No decommissioning is
therefore planned in Europe. Indeed, on the contrary, comprehensive coverage of DMEs
shall be required in ECAC airspace by 2005 and in TMAs by 2010.
The MoD liaises with the UK CAA in the provision of military DME/TACAN allocated for
primary usage. The MoD indicated that they would not want to rely solely on a spacebased
navigation solution (for security and safety reasons) – DME/TACAN systems are
therefore likely to play a significant role in the future.
3.4.4.6 L-Band GNSS
GNSS offers the potential to provide one system for all phases of flight, thus reducing the
amount of equipment carried on-board an aircraft (and the cost). GNSS is forecast to
become a ‘sole means’ of navigational positional determination in the long term (circa
2020). It is therefore a critical safety-of-life issue to protect the allocation of the spectrum
GNSS has been given (5 bands for GPS, 6 for Galileo).
Within Europe, overall space-based augmentation for GPS, GLONASS and subsequently
Galileo is planned to be provided by EGNOS (European Geostationary Navigation
Overlay System) circa 2006. More accurate timings, accuracies and integrities will be
available to the user. Other systems world-wide will provide a similar service (e.g.
WAAS). At a European level, the funds have been committed to develop EGNOS to pass
an operational readiness review (ORR) – following this, the safety case will need to be
developed before safety-of-life applications may be carried out using the system. The UK
is yet to make a firm decision on the use of EGNOS.
Augmentation may be necessary for specific phases of flight – for example, nonaugmented
GNSS height information does not meet accuracy requirements for precision
approaches. This should be provided by GBAS in the near-term, with a European
roadmap for GBAS development and implementation being prepared by EUROCONTROL.
The implementation of GBAS may allow precision approaches; work is on-going to
determine the possibility of a GNSS Landing System capable of Category II or III (current
systems, allied to GBAS, should be capable of Category I – Galileo when implemented
will also meet Category I requirements).
AIRPORT-ONLY NAVIGATION AID REQUIREMENTS
3.4.4.7 ILS
VOR/ILS localizers are standard for instrument approaches in Europe (and world-wide).
Although only short-medium range, frequency allocation problems are increasing in core
areas due to the operational requirement to frequency pair with DME/MLS.
Traditionally, marker beacons have been used in the design of instrument approaches, for
pilot awareness on the approach. However, they are now being replaced by DMEs, which
provide a much greater operational benefit.
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