FIS is a non-radar service...although you may be asked to squawk, the controller providing the service isn't looking for conflicting traffic....he may not even have a radar..London Information certainly doesn't. Admittedly, when traffic is light, the controller may give radar derived traffic information but he has absolutely no obligation to do so. Under RIS however, the controller must pass traffic info...this means that he/she will watch your track and call any conflictions fast, slow or otherwise...this is why some units (particularly around the London area) are reluctant to provide it. In respect of fast jets, they often operate below radar cover so may not be 'seen' on radar.
This is all spelt out in the AIP, which, I think you can access via the AIS website, sorry don't know the address.

I know I'll be shouted at because it's probably illegal, but for the short Channel crossing, I keep my Marine brick tuned to Ch16, in one of those clever waterproof pouches stuffed down the side of my seat, so that if we survive the ditching I can bleat to HMCG.
Anyone else do this?

Can't see any snag with that - so long as the brick is switched off in the air. I don't know what effect the brick's local RF oscillator would have on your avionics if you switched it on......

Judging by the coverage one gets these days on GSM 900/1800 on the SeaCat between Dover and Oostende or Calais, there's a good chance that you could make contact on that even in mid-channel at sea level? But of course it must be OFF in flight!

Matspart3,

Please e-mail me! Thanks.

foghorn.

keeping the fis/ris theme could someone tell me ...

1-why dont i just as for a RIS everytime.
2-when does it become obligatory to be provided with a RIS rather than FIS

like valerian i also fly out of a nw airport and throughout my training and subsequent hours have hardly ever heard anyone asking for a RIS even in some less than perfect conditions! I find myself making the standard FIS call even though sometimes i would be happier having someone keep and extra pair of eyes on me as it were! http://www.pprune.org/ubb/NonCGI/confused.gif

long final

1-why dont i just as for a RIS everytime.

It's a case of responsibility on your part. If the weather is superb CAVOK yet everyone asked for a RIS, with the amount of aircraft that get airborne on superb CAVOK days then the service would be impractical for the Controller to give - you'd just swamp him. Bear in mind that if there is IFR traffic on a RAS he HAS to give that his utmost attention. Your requesting only a FIS can help him to achieve that. If you are not happy with the inflight conditions then by all means ask for a RIS - hazy conditions and flying into a low winter sun are the prime conditions that spring to mind that a PPL without an IMC rating can still find himself in.

2-when does it become obligatory to be provided with a RIS rather than FIS

It is never obligatory - it is up to YOU to decide the level of service YOU require.

CM

Chilli Monster

thanks for the advice - sorry to labour the point regarding the question of when is it obligatory for atc to give me a RIS, but having read a few threads on pprune I have seen this issue mentioned before, i.e. pilots asking for RIS and being told it was unavailable due to high workload.
there lies my uncertainty - do i have the right to demand a RIS if i feel it necessary for safety?

longfinal

Chilli monster's advice on RIS is absolutely spot on but I think your question highlights certain misunderstandings between ATC and GA....you can 'demand' a RIS if you like but if workload is too high the controller doesn't have to provide it. The key is communication..if it's got a bit hazy/busy request RIS and tell the controller why...eg some months ago, whilst routing via BNN, Luton Approach refused RIS and gave FIS...due workload (the freq was quite busy)..however when the weather got murkier still a few miles on I reported "G-XX IMC, requesting RIS when available" which was immediately sufficient to upgrade the service. (Thanks Luton)
If in doubt, shout I suppose!

Same here. Going to Swansea once I dialled up Cardiff and didn't even ask for a FIS as the guy was busy - just monitored the frequency. The appearance of a large line of cu on track changed that option so called and asked for a RIS, stating I would go IMC in 2 miles - got it straight away. Very comforting when it goes dark around you ;)

getting clearer all the time!!
Thanks for the help.
:)

Irrespective of what you choose to do with your radio.....Could I please just add my ten penny-worth on a slightly different tack?

If your aircraft is fitted with a transponder PLEASE use it when operating in the open FIR. Also, if it has an "Altimeter encoding" setting then it's important to use that too.

Many police aircraft are now fitted with TCAS (which detects aircraft transponder outputs and presents them as icons on a small screen as a range and bearing, for those not aware). We need TCAS as an extra pair of eyes, very important due to our vulnerability when operating at low speed or in the hover. (A light aircraft up the tail-rotor takes the edge right off our day, and yours too)!

If TCAS gets a conflicting transponder target in range & bearing without attached height information, a false "Traffic, Traffic" alert (20 seconds to impact!) will be generated even though we may be well separated in altitude. This often causes an overload of adrenalin as we have to decide which way to manoeuvre to avoid this false alarm! Very worrying when the aircraft generating the warning can't be seen due to the height separation.

This problem also applies to other aircraft fitted with TCAS and it affects ATC too.

TA! SC.

This is a most interesting and relevant thread, and I have acquired more knowledge of Air Traffic Services in the process than all my PPL training.

One question - the TCAS system described by SkyCop - does anyone know if the fast miltary traffic operating in the North of England routinely carry this system to warn of the presence of GA traffic? If so this would go some way to reducing my anxiety and desire for a radar service when flying in this area.

[edited for spelling]

[This message has been edited by valerian (edited 07 February 2001).]

Valerian

No - they don't (come on - they don't even have FM immune nav kit :) )

The thing to remember is that they tend to be low level. If you're flying during a weekday in an area where you know the military operate then the best thing to do is not go below 2000ft if you can help it. That will increase your surviveability 10 fold.
CM