Menu Sign In Contact FAQ
Banner
Welcome to our forums

UK flying: LARS units vs other radar units

What is your view on getting a traffic service from LARS units vs other radar units? Is there anything special about LARS units except that they are listed in the UK AIP?

I often contact other radar units such as Thames Radar and Essex Radar for coverage outside of the Farnborough Radar range or hours of operations (Thames Radar provides coverage after 8 pm local time when Farnborough Radar has closed).

EGTF, EGLK, United Kingdom

No practical difference. If you can get a service from a radar unit, it’s all good

Whether they call it Traffic Service or (if they are busy, or you are too far away or too low) Basic Service, doesn’t really matter.

Administrator
Shoreham EGKA, United Kingdom

Thanks, my point was, there are a lot of units with radar around. Why is there a LARS list when I can also contact other units? Why not list the other units instead of one breeding to find them in the AIP in other places? In particular, certain LARS units are open only Monday through Friday whereas other airports’ radar units are open on weekends as well.

EGTF, EGLK, United Kingdom

I am sure somebody will know more details but I suspect the reason is historical. LARS are funded separately, as a service to the RAF. Military jets (well, the small ones) have an amazingly short fuel endurance so basically the whole flight is fuel critical. Also, historically, they had very limited navigation and were frequently getting lost. In later years, the LARS stations got funding continued as a service to CAS, to keep GA from busting CAS all the time, and that is probably their main role these days. And there is very little GA in the evenings because most airfields are shut. The LARS units which are shut at weekends tend to be the RAF stations, so the USSR needs to pick a weekend for the invasion

Administrator
Shoreham EGKA, United Kingdom

The origin does appear to be military, and the present rationale (as well as to keep GA from busting CAS – how well does it actually do that?) is to help GA deal with the existence of CAS through offering it a service near controlled airspace, choke points, etc. The logic seeming to be give something up (unfettered access to the sky), get something back (a service in the bits you can use).

Remember that when it was set up GA wasn’t using GPS, so if you were planning a flight that went very close to CAS but you weren’t planning to transit, a radar service was a very useful backup to constant fiddling with with nav radios to make sure you didn’t cross a certain radial from a VOR or get closer than however many miles from a DME. I’ve often heard LARS controllers saying to a GA pilot “you’ll be fine on your present track but no further left for the next 10 miles please” or some such. Either that or you had to be VMC and very familiar with landmarks around the boundaries of CAS.

Some will say pure deduced reckoning always served them very well, but would you rely solely on it if one of your legs passed within 1nm of a CAS boundary. I probably wouldn’t.

Last Edited by Graham at 03 Jul 08:24
EGLM & EGTN

What is your view on getting a traffic service from LARS units vs other radar units? Is there anything special about LARS units except that they are listed in the UK AIP?

Most LARS units provide an approach service to IFR aircraft outside controlled airspace. LARS units tend to have better service availability because they receive separate funding to incentivise them.

Other radar units already have controlled airspace to protect their aircraft, and hence typically only have capacity to provide the approach service and zone transits. They are funded by navigation service charges (e.g. when you land at the airport), or en-route charges (e.g. when you fly on a low-level airway IFR and you’re above 2MT).

I think the differentiation need not exist anymore these days (i.e. all units with a radar in lower airspace should be LARS and vice versa) but ended up this way due to the combination of UK privatisation of airports and its poor regulation, in my opinion.

My preferred procedure when VFR is to use LARS units when en-route, use radar non-LARS units for zone transits and in/outbound at the airport, and use London FIS where there is no radar coverage.

Last Edited by James_Chan at 03 Jul 10:27

James_Chan wrote:

My preferred procedure when VFR is to use LARS units when en-route, use radar non-LARS units for zone transits and in/outbound at the airport, and use London FIS where there is no radar coverage.

Agree with using LARS units when enroute and non-LARS radar units for any zone transits, however I have found that using non-LARS units also useful in areas where there is radar coverage but no controlled airspace. For instance, I have found that Thames Radar is able to provide coverage in the Lydd area where Farnborough and Southend have no radar coverage anymore.

EGTF, EGLK, United Kingdom

I have found that Thames Radar is able to provide coverage in the Lydd area

That’s interesting. I’ve never had that before. Often its a handoff to Farnborough and then London Info for me. Was that under a Basic Service or a Traffic Service?

All radar units can also offer a non-surveillance Basic Service which means they won’t be actively using the radar to issue specific traffic warnings. Your details are just kept on the strip and if they have some time, they might tell you something of use to you – but don’t count on it!

For that reason, I am no fan of asking radar units for a Basic Service.

Last Edited by James_Chan at 03 Jul 22:35

The Lydd area is covered by Farnborough East. Not offshore but generally N W of EGMD. When you depart from EGMD, flying NW or W, they hand you over to F East almost right away.

You cannot count on any service anyway. Even a Traffic Service is at controller discretion/workload. I know very well that many targets go unreported in practice (e.g. I see them on TCAS as Mode C at a reasonable height). Especially as ~half of UK GA flies non-transponder or with Mode C turned off, rendering a TS near-useless for them, to others.

IMHO the most useful thing about being in contact with a radar unit is that they ought to call you if you are going to bust CAS or, more importantly, some restricted area. In the summer the UK has loads of these (airshows mainly) and busting one is a 4-digit fine (£5000 for the Eastbourne one a few years ago). The other day I flew to Caernarfon and there was much notamed enroute (nothing actually prohibited, as far as I could tell) so I used a radar service when possible.

Administrator
Shoreham EGKA, United Kingdom
9 Posts
Sign in to add your message

Back to Top