Do as I say, not as I did this morning...

[Pilotage]

Firstly let's start with the obvious disclaimers...

- I will report this through the proper channels in the next few days.
- I am reconsidering my choice of aviation chart.

Anyhow, today. I needed to go and see somebody on the Isle of Wight, and had just taken off from Wycombe Air Park, having planned a route that was pretty much direct - initially more or less overhead WOD NDB, then overhead RAF Odiham. Nice day, nil cloud, 40km+viz, great excuse to go flying.
I was using a Jeppesen VfrGps 1:500,000 chart, specifically No.EG2 issued February 2005, which is still the current one. A short extract from it, showing my route is below (ignore the scribbled numbers, those will become clear in a minute)...
http://i24.photobucket.com/albums/c49/GenghistheEngineer/PPrune%20display%20photos/Image1.jpg

Ignore my scribbled numbers for the moment, the chart shows class A Airspace starting at 3,500ft. Wanting height (to clear above Odiham shortly) I had climbed to 3,400ft.

Roundabout WOD, I called Farnborough RADAR for a FIS (was already squawking 7000C). Was immediately told I was in controlled airspace and to descend below 2,400ft. Unsurprisingly I did.

Closer inspection of my chart showed no such thing, but assuming I'd screwed up (it happens) simply apologised and promised not to do it again.

Got to Sandown, borrowed somebody else's CAA chart for a look. That clearly shows 2,500ft, not the 3,500ft on my Jeppesen chart (would have bought one as well, but there wasn't a functioning pilot shop that I could find).

Got home at the end of a (thankfully otherwise uneventful) day and decided to check Jeppesen's website....
http://i24.photobucket.com/albums/c49/GenghistheEngineer/PPrune%20display%20photos/Image2.jpg

Damned if I can see any reference to correcting the height of that class A.
Anyhow, I screwed up - however inadvertently. I'll flag this up to the powers that be but please - nobody else do the same thing!

P

[Genghis the Engineer]

Looking at the same chart, there's a A2,500-FL245 marker at about Hemel Hempsted, but if it's applicable it's far from clear (not sure I can convince myself of it), since it's halfway around the other side of London.

G

[Saab Dastard]

Pilotage,

Without seeing the whole of the Jep chart for the LTMA it's not possible to know if your (mis)interpretation was (in)correct (delete as appropriate ;) .

On the portion of the chart in your post, though, you can clearly see the "steps" - from East to West, there's the dashed blue line marking the edge of the Sfc-2500 CTR, then the purple line running N-S just W of Henley - WOD marking the edge of the 2500+ LTMA step, then the purple line on the 1 deg W line - which is marked on your Jep chart as 3500-FL245.

On my CAA chart, the 2500+ LTMA line isn't marked as such at that location - however, it is marked clearly to the S and N of that area - right beside Wycombe Air Park, as a matter of fact :O

Is it possible that the "middle" line is noted elsewhere on the Jep chart and that you have missed it?

[Pilotage]

Looking at it in light of your and Genghis' comments, that N-S line a couple of Nm east of the one markedA3500-FL245 certainly appears to separate some other airspace - possibly that indicated by the marker at Hemel/Albans. Certainly very unclear however if this is true.

The CAA chart I looked at was certainly extremely clear as you say, and there was no doubt that this airspace started at 2,500 where I'd climbed up into it.

P

[jabberwok]

Whilst I agree that the CAA chart is clearer, the height data for that portion of airspace down to 2500ft is still tucked away to the northeast.

http://www.homepages.mcb.net/bones/WebPix/halfmil.jpg

On the CAA chart the LTMA section starting at 3500ft is much clearer, which is a big hint that the airspace to the east is lower - even though you have to look over to Hemel to find the info..

Airspace boundaries on the CAA charts are much more distinct.. (and yes, it is an old chart)..

[RatherBeFlying]

The Jepp chart seems to correctly label the A3500 floor of the LTMA which runs in a narrow N-S band in the Henley-Reading vicinity.

I do not see a Jepp label for the A2500 floor on the boundary immediately East, but an A2500 label should be somewhere in the bounded area. Just how far away is a good question.

I would pencil in A2500 over by Twyford.

[Aussie Andy]

Pilotage, mate... are you normally based in Wycombe or were you just passing through? If you are a locally based pilot them I am stunned that you are not generally aware of the nature of the LTMA airspace overhead and nearby the field.
Andy :confused:

[Pilotage]

RBF - Yep.

Aussie - Becoming local, and rapidly becoming more familiar. But like most people, learning the area from my usual chart. Something that's done me no favour on this occasion.

Jabberwork - As it happens, the CAA chart I borrowed was a 1:250,000 which was much clearer than the 1:500,000 you've showed, but that is certainly clear enough nonethless.

P

[dublinpilot]

Aw now Andy!!

Surely the point of a chart is that you don't have to be a local!

If we all stuck to our local area, sure there would be no need for charts, but that's not really practical. You should be able to read the chart quickly and accurately, and not need local knowledge.

I bought a set of Jepp charts once, and will never again. I remember looking at some of the airspace in the Irish Sea, and despite how much time I spend looking at it (on my dining room table, not in a busy cockpit), I couldn't figure out what certain bits of airspace was. Where airspace met, it was simply not possible to tell which bit turned which way.

Pilotage, you have my sympathies.

dp

[Aussie Andy]

Surely the point of a chart is that you don't have to be a local!Totally agree, I just meant IF he is local then I would be surprised he wasn't aware of the airspace overhead... but he's not exactly local...

[MichaelJP59]

I've never seen a Jeppesen VFR chart before until now, but it certainly doesn't look anything like as clear as the CAA one. Having said that, I think anyone who can provide a clear representation of the complicated airspace around London along with all the airfields and other features at 1:500,000 scale has done a very difficult job.

The other thing that occurred to me is that the Jepp chart will rely on re-intepretation of the CAA's airspace data, which is adding another opportunity for mistakes to be made "in translation".

[TotalBeginner]

My current CAA chart (1:500,000) has another height marker directly below the WOD NDB. LTMA (A) 2500+

[Mike Cross]

The CAA have a feedback form for charts at http://www.caa.co.uk/default.aspx?categoryid=64&pagetype=90&pageid=2149, you'll also find links to chart amendments on that page.
The CAA's VFR Chart Editor is off to Florida next month to do her PPL and the previous incumbent was a pilot who went on to a career in commercial aviation. Maybe it helps to have a UK GA pilot editing the UK chart.

Mike

[jabberwok]

I feel a certain sympathy for chart creators, especially those making the half mil series for the UK. There is a huge amount of information to cram into these and to make it all easily readable is no mean task. As MichaelJP59 says, the area around London must be a nightmare to draw.

It took me a while to adjust to the section of chart shown by Pilotage but I can see it has certain strengths over the CAA chart. The airfield ATZ and runway data are nicely done and railway lines clearer. On the downside layout is slightly less clear and the written data for Blackbushe is smaller type and rather distant from the airport.

The CAA charts are not without criticism either. They reproduce the lower airways system completely and the many changes of airway bases results in a lot of lines drawn on the chart that mask more important data. If a chart was produced that limited airspace data to say FL100 it would clear up some areas quite a lot. I had a set of the trial Low Level half mil charts and I thought them very good indeed.

Grumbles aside though I take my hat off to the people who do this work - I know I couldn't!

My pet hate about charts is that built up areas are shown in lurid yellow. This makes them some of the most distinctive objects on the chart although I consider urban areas low down on my list of navigational objects.

Does anyone else have a pet dislike of chart features?

[rustle]

...Got to Sandown, borrowed somebody else's CAA chart for a look. That clearly shows 2,500ft, not the 3,500ft on my Jeppesen chart.

...Damned if I can see any reference to correcting the height of that class A.
P

There's no correction required, because the section it refers to has the base of controlled airspace at A3500'.

The next purple line east (towards the LHR CTR) is where the base drops to A2500', and the WOD beacon is between that and the CTR hence within the A2500' base LTMA.

Notwithstanding the lack of numbers nearby to show the reduced base, what did you think this inner line meant?

It must surely have been obvious it was going to be lower than the A3500' of the more western line (else why draw another line), and it wasn't going to be as low (Gnd. Level) as the CTR lines -- therefore it must be between Gnd. and A3500'.

Base at A2500' or A1500' could have been good guesses as to what that line delineates.

[Brooklands]

Pilotage,
My commiserations. I have to agree that the Jep chart isn't very clear about the base of the CAS in the area.
Having done all my flying at Wycombe, and only every used the CAA charts I've always been aware of the varying heights of CAS in the ATZ (anything between 2500' and 4500'), and I'm pretty sure the boundaries have changed over the years I've been there (perhaps I'll dig out an old chart and check that). It does mean that you need to keep your wits about you, eg if departing off runway 24 towards the CPT VOR initially the base of CAS is 3500', but your track will clip the corner of the 2500' section of CAS near Henley.
There but for the grace of god go most of us.
Brooklands

[Aussie Andy]

There but for the grace of god go most of us.Absolutely, and I didn't mean to sound too critical above... we are all capable of it!

As it happens, I have just bought a Jepp Nth UK / half or Northern Ireland chart to facilitate my forthcoming trip to visit DublinPilot via IoM and NI - becaiuse the new CAA version isn't out until May and I didnn't feel like forking out £15 for an out-of-date one... the Jepp non-laminated was current and about £9. So I guess I will be checking and re-checking various bases of CTA carefully!

Andy

[Flap40]

What is the grey line on the Jep chart that runs north/south and is aligned with the 2500ft boundary?
It does not feature on the CAA chart and it does help in hiding the line on the Jep chart.

[Aussie Andy]

map fold?


:ok:

[Flap40]

map fold?
:ok:
No the fold is further east. The line I mean goes through Stokenchurch mast.

[Superpilot]

Flap40,

Good question, and it's probably that very grey line that adds to the confusion, by discolouring / mixing with the the purple control zone line. The grey line is part of a very large rectangle covering the whole South East Area.

[rustle]

Having done all my flying at Wycombe, and only every used the CAA charts I've always been aware of the varying heights of CAS in the ATZ (anything between 2500' and 4500')...


That's not strictly correct :8

With an airfield elevation of 520', the ATZ will only go up to A2520'...

[Brooklands]

Rustle,
Yes, I should have said: "...varying heights of CAS above the ATZ (anything between 2500' and 4500')...".

That'll teach me to read my posts properly before hitting the submit button.
Brooklands

[atb1943]

Thank you all for your comments.

You can be sure that the boys in the back room will be scouring the new EG-2tomorrow that arrived from the printers today!:ugh:

brgds

atb

[PPRuNe Radar]

The CAA charts are not without criticism either. They reproduce the lower airways system completely and the many changes of airway bases results in a lot of lines drawn on the chart that mask more important data. If a chart was produced that limited airspace data to say FL100 it would clear up some areas quite a lot. I had a set of the trial Low Level half mil charts and I thought them very good indeed

I remember seeing CAA charts in the past with info limited to 6000' (I think). Can't remember if they were for a trial, or for public issue but now discontinued though. :ugh:

[Genghis the Engineer]

You'd have thought that 10,000ft would be more sensible since that's the effective ceiling of the majority of GA.

G

[Final 3 Greens]

Also the max alt for VFR? IIRC?

[rustle]

Also the max alt for VFR? IIRC?
No. There isn't one.

The only restrictions to VFR are weather or airspace classification. (No VFR in Class A).

[FullyFlapped]

Just to get back to the original point, the Jepp VFR chart I have actually does annotate the limits for this piece of airspace, but the label is positioned just to the north of Hemel - you've got to really follow those pesky little lines around !

FF :ok:

[Aussie Andy]

I think Heathrow were on easterlies on Wednesday morning, so if you thank about where you were at Woodley at 3,500 you'd have been 16NM due west of the landing runways, and possibly < 1,000 below the final approach traffic... makes the eyes water! Still, it was a gin-clear CAVOK day so I am sure you'd ahve seen the heavy traffic had it come to that...

Andy :uhoh:

[aw8565]

I'm a student PPL out of Biggin. On a nav excersise the other day and first time I'd flown in ages. I know all about the LTMA at 2500 and still I managed to almost pay it a visit. It was a bumpy day etc but I guess that's no excuse.

Wasn't till after I'd landed back at Biggin that my instructor said my chart was out of date. I'd only used it a couple of times as my flying has been so patchy recently so it must still be valid right? WRONG!

Ah, a lot to learn!

I guess it could have been worse, you could have been non radio and caused a real problem. Airliners have TCAS for that sort of thing it's nothing to worry about.

Like I said a lot to learn...! :rolleyes:

[dwshimoda]

I guess it could have been worse, you could have been non radio and caused a real problem. Airliners have TCAS for that sort of thing it's nothing to worry about.

Like you said, you do have a lot to learn...

[aw8565]

Ok that was a joke, tongue in cheek....

[chevvron]

Jepp VFR/GPS charts need to carry a health warning. I bet they still don't show Lasham as an active gliding site with a cable launch hazard as high as 3700 ft amsl! Don't forget, there is no independent organisation checking these charts to ensure the accuracy of the info they depict(likewise Jepp IAP plates), although Jepp claim their own internal procedures provide this 'safety net'.
Aussie Andy: The reason the CAA chart isn't being published 'til May is that there will be airspace changes included in it which probably won't appear on your April Jepp, so you'll have to buy another chart anyway!

[Aussie Andy]

so you'll have to buy another chart anyway!No, don't think so - in 6yrs of flying this'll be my first trip to Eire, so doubt I will be needing the Irish charts again anytime very soon, and only the second time I have travelled north of Liverpool as well! I am hoping to travel further north later this year, and so when / if that trip comes about I will buy the CAA chart then.

In the meantime I will just have to keep my eyes peeled as I use the Jepp charts in Ulster on this trip (I have an Irish IAA chart for the Republic kindly sent over to me by DublinPilot, but this hasn't had an update published in some years! ... DP has provided me with the key changes I need to know for hand-amending that chart...).

Andy

[englishal]

My GPS shown the Portland MATZ from the RNAS there.......do I need a dB update?

:}