Farnborough LARS = Transponder Mandatory Zone?

[Nipper2]

I'm surprised no one has mentioned this before, but am I just being cynical when wondering if the expansion of Farborough Radar is just a prelude to the first Transponder Mandatory Zone?

Anyone from our ATC friends care to comment?

[rustle]

I'm not ATC, but I doubt the two are related any more than any other RIS/RAS provider and TMZs.

TMZs are coming that's for sure: Long time overdue considering how congested it is in the SE.

[chrisbl]

For those who sing the praises of the US, around their major airports (class B airspace) , there is a mandatory Mode C veil of 30 miles radius.

[mm_flynn]

For those who sing the praises of the US, around their major airports (class B airspace) , there is a mandatory Mode C veil of 30 miles radius. Which is sensibly managed so those people who truly can not fit Mode C are accommodated and everyone else fits into a good system. Why people with electric systems over here don't squawk with alt is beyond me.

Of course with all of those Mode C aircraft in the US their radars would be full of Fruit and Garble and need mandatory Mode S - except for the fact that American airspace has better performing aircraft and radars so they don't have this problem ;).

[rustle]

There are also a good few track miles between various TMZs in the US, whereas were the climb-profile/"busyness" tests applied to various CTRs/CTAs/ATZs over here and TMZs were applied accordingly there wouldn't be.

Someone drew a map of what the UK would look like with these TMZs according to US spec once - ISTR it made the case for the whole FIR quite nicely ;)

[bookworm]

Someone drew a map of what the UK would look like with these TMZs according to US spec once - ISTR it made the case for the whole FIR quite nicely
You've forgotten how that one ended, haven't you?!

[rustle]

You've forgotten how that one ended, haven't you?!

I know it ended in tears, but I can't remember whose tears ;)

[NorthSouth]

If you make the whole of the sub-LTMA airspace a TMZ you will immediately get a massive rash of spurious TCAS alerts from all the GA aircraft climbing up to 2499ft. I'm sure NATS will already have done that risk assessment. It's instructive to take a look at some of the radar videos of infringements around the LTMA on flyontrack. Take a look at how many primary-only tracks there are crossing underneath the final approaches for Heathrow, Gatwick, Stansted. At the moment they're ignored by controllers, as the regulations provide/require. If all of those are squawking, the controllers may well be more relaxed but the pilots of the airliners - who until now have been oblivious to all those movements underneath them - will be getting TCAS TAs/RAs at just the point where they're focusing on establishing on the localiser.
NS

[hobbit1983]

Someone drew a map of what the UK would look like with these TMZs according to US spec once - ISTR it made the case for the whole FIR quite nicely

I'm curious - does anyone have a link to this please?

[mm_flynn]

I'm curious - does anyone have a link to this please? I doubt it. There were some tears in debating how the rules would apply. In the US it seems to be necessary but not sufficient to have 5m pax and 300,000 movements (of which 240,000 must be CAT) to have Class B airspace (which is what then gives rise to the veil). There are several UK airport's that make it on Pax, but I think only Heathrow makes it on all three requirements. However, you could argue that the whole London TMA should be considered- given the Pax volume at Luton, Stansted and Gatwick and also that Manchester and Birmingham Pax volumes would justify Class B. If you argue that 5m pax only would do it (which is definitely not true in the US) then you would get 'most of the FIR' covered.

So the map looks like a 30 mile circle around LHR, or 15 30 miles circles spread around the country, or something in between!

[rustle]

I'm curious - does anyone have a link to this please?
I'm sure I can find it somewhere - but be warned: Last time the lid came off this Pandora's Box it wasn't pretty.

There were tears before bedtime, dummies spat, Christmas card lists re-written... In a word, Bedlam. :rolleyes:

[Saab Dastard]

Was Mode S in the picture when the TMZ was last discussed?

SD

[IO540]

If you make the whole of the sub-LTMA airspace a TMZ you will immediately get a massive rash of spurious TCAS alerts from all the GA aircraft climbing up to 2499ft

Since most regular pilots already fly with Mode C/S everywhere, this must be happening already.

I am going to get jumped on over the above comment, but except for VFR-only aircraft and aircraft without electrics, and civil liberties diehards who make sure their transponder (if fitted) is OFF, the "transponder war" is now effectively over.

[Fright Level]

If you make the whole of the sub-LTMA airspace a TMZ you will immediately get a massive rash of spurious TCAS alerts from all the GA aircraft climbing up to 2499ft

I doubt it very much. Take a look, for example, at the the EGLL SID's. Most have you above 3000' as you cross the CTR boundary, so there's already 500 separation. Don't imaging that a/c in controlled airspace are all flying around at 2501 feet with GA whizzing by at 2499. In most cases, departing (and arriving) traffic will have a much greater vertical spacing due to vectoring routes and better climb rates.

[Rod1]

“I am going to get jumped on over the above comment, but except for VFR-only aircraft and aircraft without electrics, and civil liberties diehards who make sure their transponder (if fitted) is OFF, the "transponder war" is now effectively over.”

If you add up the micros, the gliders, the PFA aircraft etc etc then the total number of VFR aircraft is vastly bigger than the number which are IFR capable. So you have just said that if we ignore the majority of aircraft …

Agree Transponders should be on if possible.

Rod1