Crossing ATZ above 2000ft - need to call in?

[hippo123]

Sorry to resurrect this thread, but would it be appropriate / correct to "request basic service" from Stapleford in this situation? I have heard it done at this and other A/G aerodromes before and have wondered about this.

It does appear to provide a useful shorthand for "uh, hello, I'm going to be overflying your aerodrome just above the limits of your ATZ and would like to let you know I'm here, and also would like to know who else is in the vicinity".

EDIT - Meant to quote the following, but don't appear to be able to / know how to:

Quote:
On a "Basic Service", Stapleford will generally confirm their QNH, runway in use and any known circuit, joining or over-flying traffic

Just a quick off-topic question to clarify something. Stapleford are A/G so are not able to give a Basic Serice, is that right? I fly from a busy A/G airfield in the South East and have never heard any type of service given (although one chap once asked for a Traffic Service!).

[dagowly]

It is, for all intensive purposes, a basic service. It's in the name. As it doesn't have to be surveillance derived they can provide it. A lot of military ranges are A/G and provide A basic service.

[chevvron]

Basic Service is an air traffic service. A/G is not an air traffic service unit and A/G operators are not qualified to provide full 'basic service', however they will usually pass information on known traffic to enable pilots to decide an appropriate course of action. If the A/G airfield is licensed, you must establish 2 - way contact in order to penetrate the atz and I would suggest also if you are passing within say 1,000ft over the atz 'just in case' as people may sometimes do aeros overhead the airfield above the atz (they used to at Popham f'rinstance)

[hippo123]

chevvron / dagowly - thanks for your replies.

I realise I'm being a tad anal about this, but my query is specifically about precise RT phraseology.

My question should have been: Is the phrase "request basic service" (spoken over the radio) appropriate in this particular situation?

If it's not, then what would be the appropriate phrase to request that they...

"pass information on known traffic to enable pilots to decide an appropriate course of action"

along with QNH, field in use, etc.

(as they do at AFIS aerodromes when someone "requests basic service" from them).

[tmmorris]

I'd suggest 'G-ABCD is a PA28 transitting through the overhead at 2500ft, estimate overhead time 55, request QNH and any known traffic'

That's not asking for a service they can't provide, it enables them and anyone working that frequency to anticipate your arrival (and let you know if they are doing anything which might be a problem e.g. aeros), and gives you a precise QNH so you are where you say you are.

[phiggsbroadband]

Timing is also important.

It is also prudent to call up the A/G operator say 2-3 minutes before going through their overhead... At 120kts that is at a range of 4-6nm. The LARS station was probably hinting that now would have been the best time for the call.


Given the time taken for circuit traffic to pass their calls, you may have been able to hear up to 5 planes in the circuit.


A further wait of 2-3 minutes once through the overhead would give you details of arriving and departing traffic.


.

[piperarcher]

As what tmmorris said. You can't request anything from an AG, only tell them what you are doing and see if they tell you anything. You can ask anything you want like other known traffic but different aerodromes will offer different levels of helpfulness, if indeed any response - they don't have to. Once or twice I bothered to contact Stapleford then re-establish contact with Stapleford but as Peter said in one of the original replies, what can they officially tell you?

I fly the track between Stapleford and LCY a lot, and with farnborough I either tell them I'm routing around the south, or they will figure it out anyhow. If you don't have a GPS, make sure you have positively identified Stapleford and are sufficiently south enough to not be in their zone, but not so far south you've busted LCY.

[soaringhigh650]

If it's not, then what would be the appropriate phrase to request that

The matter is moot.

For pretty much all the reasons given by IO540 at the beginning of this thread, there is absolutely no reason to waste time of everyone calling up any facility unless you want to go into it, or they are qualified and appropriately equipped to provide you with traffic advisories outside their boundary.

Either keep quiet or remain on flight following / flight information services if you so wish, keep a good lookout and enjoy flying.

Don't knock on every man's door for the sake of knocking or you'll overload the system.

[robin]

Hmm

When I return to Elstree from the SW I tend to go overhead Wycombe, where possible.

Normally Wycombe Tower are happy for me to do that, but the last couple of times, they have said go round the ATZ not over, as gliding was in progress.

No skin off my nose to edge round the ATZ, but it is quite a squeeze between the TMA and Wycombe. I know I'd be in my rights to go overhead the ATZ, but what do others do?

[500 above]

No skin off my nose to edge round the ATZ, but it is quite a squeeze between the TMA and Wycombe. I know I'd be in my rights to go overhead the ATZ, but what do others do?

Not really a squeeze. There are plenty of good landmarks to use.

Only a numpty would fly overhead an active gliding site, although you may be "in your rights to go overhead the ATZ".

[chevvron]

It is a squeeze between the TMA and Wycombe ATZ, but that's overhead the airfield. Another squeeze is to the east between the ATZ and the Heathrow CTR, which is what I would guess Robin actually means!!
Roll on the 18th when the classification changes.

[500 above]

The East of the ATZ is what I am referring to. Not a squeeze at all.

It is a worry that people would want to route overhead an active gliding field none the less. What next? Just route overhead the departure end of a busy biz jet airport above ATZ height without comms? Go through a localiser to a busy GA field - aka G-EYES accident (in which I lost a good friend in a mid-air) Safety is our prime concern guys, let's use all the tools we have in our inventory to maximise this.

All the above may well be legal, but it does not make it safe or professional.

[flyme273]

I'm with IO540 and wsmempson on this one.

Remain with Farnborough radar. They have the ability to notify a transponder conflict (equipment software is probably auto detecting). Eyes outside 100%.

Stapleford can't provide any more than general info - probably limited to circuit info. All talking and eyes inside to change frequency. By the time radio calls are made and returned a good few "unprotected" miles have passed.

flyme.

[chevvron]

When I did Farnborough LARS, I liked to say 'keep your own separation from XXXX atz'. That leaves the decision entirely up to the pilot.

[PA28181]

It is a squeeze between the TMA and Wycombe ATZ

More than a "Squeeze" if going south with Wycombe at 520' it's one or the other.......

[GCRSR]

For me this thread highlights a serious issue... There are a multitude of different opinions about the "correct" way to overfly aerodromes and transit key routes in some of the busiest GA corridors (PINCHPOINTS such as Wycombe, Stapleford, Blackbush) around London.

Would it not make sense to agree some VFR routes that kept eastbound and westbound or northbound and southbound traffic separated with agreed heights and radio frequencies?

I for one find it incredibly frustrating that there is so much regulation in the name of safety which focussed on the small issues and yet big picture stuff does not get addressed.

Given that it is almost essential to navigate with GPS around the London area to stay legal it should not be overly complex to create some routes with standard waypoints that would minimise head-on risks.

In the last year I have found myself taking avoiding action from opposite direction traffic at the same altitude when routing north around Wodley and South near Stokenchurch and on both occasions whilst receiving basic service from Farnborough West.

Creation of traffic lanes like the ship traffic separation in the channel between Dover and Calais would surely help.

[Heston]

"Given that it is almost essential to navigate with GPS around the London area to stay legal it should not be overly complex to create some routes with standard waypoints that would minimise head-on risks."

Oh yeah, what a great idea! But let's go one better than that and just make it all controlled airspace, mode S mandatory. Then we can all play at being airliners.

[172510]

Stapleford is quite a choke point vertically, with the ATZ up to 2185 and then the LTMA at 2500, so any other traffic is prob90 at 2300 as well.

Just some hair splitting:

The accuracy of an altimeter (cf ICAO Doc 8168) should be +/-60ft
So I should make sure to fly below 2440 and above 2245 to make sure I'm out of the ATZ and out of the LTMA.
Let's say I choose to fly in the middle, at 2342.5 ft
I have to keep my altitude within +/- 97.5ft, which is more accurate than PPL standards (+/- 150ft) and even CPL standards (+/- 100ft).


I think that the floor of the LTMA is on the London QNH. To avoid the ATZ I should fly over 2185 on Stapleford QNH. Meaning that if Stapleford QNH is lower than London QNH, I have to keep my altitude even more accurately (27ft per mb).

[soaringhigh650]

should not be overly complex to create some routes with standard waypoints that would minimise head-on risks.

Creating standard routes does not minimize head on risks. It would actually increase collision risk slightly by bunching airplanes together. So having some randomness is good.

But there are suggested routes which you can fly which nicely avoids controlled airspace if you don't wanna transition through it.

See: CAA VFR - Video Guides 692-1

[Talkdownman]

Originally Posted by 500 above

The East of the ATZ is what I am referring to. Not a squeeze at all

A 'standard route' of mine…the BNN222R…

Meaning that if Stapleford QNH is lower than London QNH, I have to keep my altitude even more accurately (27ft per mb)

UK IAIP ENR 1.7-2 Paras 5.1.6, 5.2.2.1 and 5.3.3

It may be assumed that for aerodromes beneath the same TMA or CTA the differences in their QNH values are insignificant.