Has GPS killed off the VOR?

As most UK General Aviation (GA) pilots must have noticed, the world is going through a period of rapid change.

Technologies that have been common place for decades will soon be superseded – and that includes a reduction in the number of ground based VOR (VHF Omni Directional Radio Range) beacons in the UK.

Each beacon is part of a post-World War II ground-based navigation network used for defining airway routes or providing instrument approaches at airports. They’ve been part of the commercial aviation and instrument training world for decades, but the march of technology has finally caught up with them.

Commercial aviation – which has always funded the upkeep of the VOR beacons – now almost exclusively relies on the use of satellite navigation (read last week’s post on EGNOS for an example), making the majority of beacons an expensive and unnecessary financial burden. As such by 2020 we will be reducing their number from 44 down to 19.

The removal of outdated VORs has already started, with Cranfield (CFD) being the first to be decommissioned, followed by Dean Cross (DCS) at the end of 2014. The VORs being assessed for withdrawal are Glasgow (GOW), Perth (PTH), Turnberry (TRN), Inverness (INS) & Benbecula (BEN). NATS will then gradually move down the UK removing VOR’s from service that are no longer required.

It is important to note that any co-located DME will remain as part of a strategically selected safety backup to commercial aviation in case of GPS signal failure.

The VOR beacon at Daventry by Alex Donohue via Flickr

Despite being designed for use by commercial aviation, the VOR network has always been a valuable aid to GA pilots as well, so it’s important to prepare for their removal.

The transition to fewer VORs will be managed to minimise impact, but it is clear that thought will need to be given to redesigning some GA training, or operating practices which have always assumed excellent VOR signal coverage at lower levels. It is also likely that the EASA instrument rating test will have to include a mandatory GPS based approach in the not-too-distant future, forcing trainers to upgrade and re-emphasise.

The NATS team has already visited a number of PPL training organisations to engage with them on minimising the impact and to discuss alternatives as nearby VORs are considered for removal. For example, PPL schools far removed from a VOR ground position may have to examine or perhaps re-route traditional VFR routes so signals can still be received in order to include it within their training.

Of course there are alternatives to VORs. Unknown to many, the basic PPL syllabus actually gives equal prominence to GPS training for radio navigation as it does to other methods. As most qualified pilots fly with some form of GPS nowadays, we can move PPL and instrument flying training into the 21^st Century by embracing the techniques, skills, and relevant threat and error management aspects of GPS equipment as part of basic radio navigation even for PPL students.

We will of course will continue to work with the GA community to keep you informed as the VOR rationalisation project progresses. The FlyOnTrack website will give the pointers you need to find this information over the coming months and years.

[Header image by Phil Collier, NATS engineer]