Mid air over Hertfordshire

[Aussie Andy]

Whirlybird: spot on... I vote for your suggestion re- lane frequencies!

WWW: as per slim_slag, what you fear did occur in LA areas (OK, San Diego perhaps...) and this led to introduction of the 30NM mode C veils surrounding Class B over there AFAIK.

Capt. Manuvar: there are already insufficient codes so no scope AFAIK to use last two digits as you suggest. Also it would be very prone to human error given that we are already capable of forgetting to put the thing on or in mode C at all !

Andy

[Wee Weasley Welshman]

I'm sorry but hitting the engine block of a C152 at 300mph is going to have a seriously negative impact on the controllability of an airliner.

Mode S is the answer and mandatory Mode C would be a leap forward. Think about it chaps. The last ten years alone have seen Ryan and Easy alone put an extra 150 Boeings into UK skies. Everything is expanding at breakneck speed and its only going to get worse. What's a bit ropey now will be unacceptable in another 10 years time. And I include the use of airspace by the fast jet community.

The US has universal RIS everywhere. We don't have that and we never will. Given the topsy turvey piled on top of itself complex airspace we have to live with on this congested Island it wouldn't work very well anyway.

See and avoid is rubbish. An invention from the 30's that relies on Big Sky Theory. The hours I've spent trying to spot 757s coming head on at 10 miles and not being able to... Just because YOU don't fly anywhere near any other type of commercial flying doesn't make a good argument for saying therefore nothing should be done nationwide.

I'm all for keeping the cost down. Lets have Mode S for GA and lets get the CAA to subisidise it and levy a special quarter percent tax on every airline ticket for a year. That would cover it all easily.

Cheers

WWW

[Whirlybird]

WWW,

I'm all for keeping the cost down. Lets have Mode S for GA and lets get the CAA to subisidise it and levy a special quarter percent tax on every airline ticket for a year. That would cover it all easily.

Hello!!!!! Reality check please!!! Do you honestly think this is ever going to happen? From what I know of the CAA, the airlines, competition, the travelling public, attitudes to GA, plus life generally, it ain't - not never no how. Nice idea, but...let's be realistic here.

[Kolibear]

It occurs to me that we have to seperates issues here - GA vs GA and GA vs Airlines.

As WWW says, airliners are being forced to divert to avoid a non-existent threat from GA aircraft thousands of feet below them . Fitting TCAS in this case will be of no benefit to the GA aircraft but of real benefit to the airlines. In this case, it would be nice if the end user was to pay. If a commericial case could be made for the airlines saving money by fitting the entire GA fleet with TCAS, then it might happen.

In the GA vs GA case, it would require us to stump up for the avionics and it would also require a massive expansion in ATC services just to keep an eye on GA fliers. That will just not happen.

[TonyR]

When I were a lad, it was the job of ATC to keep IFR traffic away from VFR, and VFR was simply visual flight rules.

What has changed?

[bookworm]

When I were a lad, it was the job of ATC to keep IFR traffic away from VFR, and VFR was simply visual flight rules.

Nothing has changed. It's still not the job of ATC to keep IFR traffic away from VFR.

[M609]

Nothing has changed. It's still not the job of ATC to keep IFR traffic away from VFR

Some might argue that is is subject to debate, it's not all class D or G you know.....

(Hint, C and B)

[robin]

Surely they do if IFR traffic is operating under a RAS. I thought they aim to maintain a 5nm/3000' separation where practicable

[PPRuNe Radar]

With regard to XPDR codes, how about a dedicating the last two/three digits to altitude(regional/fligh level?) e.g flying at 3500' squawk 7035, or an aircraft at 12500' will squawk 7125. I don't know too many people who fly at 50000, 60000 and 70000, so it shouldn't conflict with the emergency squawks.

What do I set if I fly at 8000' or 9000' ??

[FNG]

Oh great: change your squawk every time you change altitude. What if you forget? Fly around broadcasting that you are at xxxx feet when you are at yyyy?

[englishal]

You could have a little mechanical unit containing a barometric altimeter which attaches over the code knobs. As you change altitude, it could automatically twist in the new code

(hang on, thats almost inventing Mode C )

[PPRuNe Radar]

Good idea ... in fact, do the twisting internally and send it as another data part so that it is transparent to the pilot, is done automatically as the aircraft changes altitude, and can only be seen by ATC bods. That would free up the 4 digits for other uses.....

I like your name for it englishal ....... ''Mode C'' ... sounds very snappy

[bookworm]

Nothing has changed. It's still not the job of ATC to keep IFR traffic away from VFR.
...
Some might argue that is is subject to debate, it's not all class D or G you know.....

(Hint, C and B)

Point taken M609. I acknowledge that the response was a little parochial. But this thread is focussed on avoidance of collisions in the airspace below the London TMA. In the UK we have no class C and no class B below FL245.

[Capt. Manuvar]

My crazy idea is aimed at those who have mode A but are can afford or don't want to upgrade to Mode C.
Englishal
I'm very much aware of Mode C and how it works, thank you.

[AlanM]

And who is going to provide the RAS outside CAS in the South East??

Luton, Thames, Heathrow, Essex, gatwick etc all too busy with there own airways traffic!! That just leaves Farnborough and Southend (Southend are primary radar only so harder to do!)

And yes, 5nm or 3000 feet isn't too easy in a busy choke point when the base is 2.4A! That is why we seldom offer a RAS - it is unachievable.

[slim_slag]

Don't worry, CM, the airlines are going to have a whip round (or rather pass the cost onto the passenger via a ticket surcharge) and pay for you to have a nice new Mode A transponder with ten numbers in it! Mode W they will call it, yeah right....

I think it's reasonable to say that a fair part of the GA community will spend money on kit if they think they are getting a benefit. If I was flying under London TMA (or anywhere in the wildest parts of the UK for that matter) I'd consider something that increased my safety by reducing the chance of a mid-air a major benefit. I tend to agree that 'see and avoid' doesn't really work outside the traffic pattern and the best way to improve safety is to get a radar service. Unfortunately ATC in the SE of England are under-resourced and have their work cut out working scheduled air services. So the GA plane cannot get a decent radar service most of the time. The only time I really use a transponder for my own benefit is when I'm receiving a radar service, and if it isn't available there really honestly isn't any point in me paying for a decent transponder.

So back into cloud cuckoo land. If the airlines were so worried about GA traffic (and I don't see any evidence of this), and they are also worried about creaking ATC services (I think there is evidence of this) why don't they just pay to hire a bunch more of those very well trained controllers? As well as working the heavy iron, these extra controllers will also be able to provide a decent radar service to GA traffic in the choke points around London. Now as a GA pilot, if I thought I had a very high chance of getting radar service in busy airspace I'd pay for my own transponder. If everybody else thought the same way then the chances of two GA planes colliding would be reduced significantly.

One can dream!

[PPRuNe Radar]

My crazy idea is aimed at those who have mode A but are can afford or don't want to upgrade to Mode C.

I'll ask again then ... what do I set if flying at 8000' or 9000' ????

[boomerangben]

PPrune Radar,

I reckon that you would be ok above 7400' - not much GA traffic up there and ATC might give you your very own one anyway.

Whole "Squawk your height" idea is unfeasible, since most squawks are already allocated.

[VP959]

All this talk of radios, transponders etc is grand, but what about the hundreds (perhaps thousands) of us more impecunious aviators?

Take the flying machine sat outside my abode at present. It has two seats, no electrical system, a "yachtie" disc-in-a-tube type air speed indicator, no fuselage, no instrument panel (so no instruments bar the above mentioned ASI). I paid the princely sum of £1,800 for the whole machine, including a road trailer and full set of covers.

The annual cost of maintaining and permitting the thing would be less than £150 all in, yet it has the capacity to provide endless hours of very cheap, fun flying, more or less just for the cost of the fuel.

Why should I be forced to pay far more than the aircraft's value just to fit a bit of kit that I will never have occasion to need? At present that's just what the rules say I will have to do, if compulsory Mode S comes about.................

[Aussie Andy]

Why should I be forced to pay far more than the aircraft's value just to fit a bit of kit that I will never have occasion to need?

If you lived and wanted to fly in the US then as I understand it (could be wrong..) I think you would have to invest in a transponder at least if you wanted to fly within 30NM of e.g. SFO or other major Class B airspace so that your primary radar return did not cause grief for the radar APP controllers in that area who are vectoring IFR traffic through Class E, D & B airspace whilst permitting maximum freedom to other airspace users. The equivalent to that here would be when IFR are vectored through class G when approaching a number of airfields (e.g. Biggin).

Such a mode C veil would give you the choice of either choosing to comply by either equipping your current steed if feasible, or doing as the rest of us do and renting (or buying a share in) an aircraft type which is equipped with a transponder for flying in the more dense areas. Or, you could limit your flying to less dense areas away from the mode C veil and continue with your current type of flying there.

That would be the argument - but I don't see it happening here. Instead we seem to be leapfrogging this and forcing everyone to use mode S for little or no apparent benefit to GA. My view on mode-S would be different if ADS-B was to be part of the plan here, but it doesn't seem to be (whereas in both the US and Australia there not only clearly detailed policy goals in relation to this new form of surveillance, but there are also pilot programmes under way).

Andy