Airliners mixing it with gliders and puddle-jumpers?

[BugOutWest]

I've just been reading an old, closed, thread "LTN arrivals" and wonder about some of the arrivals which seem to have started flying at lower alts over Cambridgeshire, below the controlled airspace with base 5,500ft msl.

I noticed a twin-jet flying southwest over Gransden Lodge when I was flying near there in Nov 09. It was at 4,000ft (level with me) and overhead an active glider site. A few days later I was on the ground at that airfield and a similar flight occurred. Recently [I was on the ground in my garden and] noticed something similar and complained to Luton, who told me that it was an Easyjet positioning flight. It was 10 Apr and I reckon LTN were on 08 that day.

This increase in activity bothers me because it is over where I live, but more to the point it seems less than sensible for airliners to be mixing it with gliders who are all but invisible to the eye and radar. Why are they not above 5,500ft and in the controlled airspace?

[Vortex Issues]

complained to Luton

Why? surely they have the same right as you in be in Class G airspace.

Why are they not above 5,500ft and in the controlled airspace?

The jet could have been on it's way back from an air test to the north or out of Cambridge. The a/c can't simply join controlled airspace at any level due to other traffic that may already be there.

It may have been more expeditious for the jet to join Luton at 4A so as not to get in the mix of Essex traffic.

The default clearance for aircraft coming out of Cambridge that want to join controlled airspace to the south is to fly towards Barkway at 2.4A and contact Essex Radar. Essex will then when able give that aircraft further climb and routing in instructions when it's safe to do so.

[10 DME ARC]

Just look at the likes of Newcastle 40% of the IFR inbounds route through class G airspace mixing it with fast jets not so fast jets, gliders, light aircraft, micro lights, hang gliders etc etc. With only one linking airway from the South West what else can they do!

[BugOutWest]

Why? surely they have the same right as you in be in Class G airspace.

I don't dispute that; I complained about an airliner going over my house at 4,000ft, not about the one in the same Class G airspace as me.

Quote:
Why are they not above 5,500ft and in the controlled airspace?
The jet could have been on it's way back from an air test to the north or out of Cambridge. The a/c can't simply join controlled airspace at any level due to other traffic that may already be there.

I don't think you can have read my post: it was an Easyjet positioning flight that flew over my house. That doesn't sound like an air test.

It may have been more expeditious for the jet to join Luton at 4A so as not to get in the mix of Essex traffic.

The default clearance for aircraft coming out of Cambridge that want to join controlled airspace to the south is to fly towards Barkway at 2.4A and contact Essex Radar. Essex will then when able give that aircraft further climb and routing in instructions when it's safe to do so.


Thanks for the explanation, anyway.

This monitoring on my part came as a result of the flawed and aborted NATS consultation last year (or was it the year before). The argument was started among non-aviation types in the area about the base of the holds for STN and LTN, whereas my assertion has always been that the base altitude is immaterial: the aircraft will drop out of any stack when it can and make its way towards the approach at whatever altitude the captain decides with ATC. It's the general practice that we, the public, need to consider, not the holds and their altitudes.

[BugOutWest]

Just look at the likes of Newcastle 40% of the IFR inbounds route through class G airspace mixing it with fast jets not so fast jets, gliders, light aircraft, micro lights, hang gliders etc etc. With only one linking airway from the South West what else can they do!

Thanks for that information. But my question is, is it sensible or good airmanship to mix it with light aircraft and gliders? How is separation from gliders maintained?

[Vortex Issues]

I don't think you can have read my post: it was an Easyjet positioning flight that flew over my house. That doesn't sound like an air test.positioning from where? in which area do you live?

the aircraft will drop out of any stack when it can and make its way towards the approach at whatever altitude the captain decides with ATC.The captain does not decide what level they leave the stack at. The approach controller manages the stacks, gives vectors from the stacks and descends the aircraft. Normally the aircraft will leave the stack at min stack level, FL70 or 80 normally (depending on the QNH)

flawed and aborted NATS consultation (http://www.consultation.nats.co.uk/uploads/TCN-PartEv2.pdf)The changes they wanted to make would have decreased the noise heard for many people, kept the aircraft higher for longer and decreased the area in which the aircraft were flying. It would have also given a separate stack for Luton inbounds and therefore keeping them higher for longer instead of being restricted to 5A flying E to W over Duxford/Fowlmere/Royston area which happens now.

How is separation from gliders maintained? You don't, it non-controlled airspace

[HEATHROW DIRECTOR]

<<the aircraft will drop out of any stack when it can and make its way towards the approach at whatever altitude the captain decides with ATC. >>

The writer of this gem is, apparently, a QFI. I am surprised at his lack of knowledge.

[spekesoftly]

The irony of an ex-mil FJ pilot complaining about noise and seemingly also unaware of the "see and avoid" principle in Class G airspace is not lost on me! :rolleyes:

[Roffa]

This increase in activity bothers me because it is over where I live, <snip>

BugOutWest, for someone who has if your profile is to be believed spent their life in aviation, a lot of it at my expense as I'm a tax payer, I find this to be NIMBYism at its worst.

When you were blatting about yourself making lots of noise in FJs, did you ever spare a thought for the folk you were making noise over? A modern airliner must be much quieter than a 1980s vintage mil jet.

[BugOutWest]

<<the aircraft will drop out of any stack when it can and make its way towards the approach at whatever altitude the captain decides with ATC. >>

The writer of this gem is, apparently, a QFI. I am surprised at his lack of knowledge.

Well, I suppose that's why I'm airing my ideas here. I don't know much about controlled airspace, except when I have been forced to use it -- very rarely. That's what the RVCs are for.

And how the rules are laid out and how operators operate are sometimes subtly different.

For instance, I know that I may fly at 2,000ft over an ATZ, or 3,000ft over a MATZ, but to do so without talking to ATC would be poor airmanship and perhaps more than a little dangerous.

So, my point is, that it's just as risky and lacking in airmanship for a large aircraft to fly over a glider site at or just above the top of the launch envelope without knowing where the gliders are flying.

[Vortex Issues]

that it's just as risky and lacking in airmanship for a large aircraft to fly over a glider site at or just above the top of the launch envelope without knowing where the gliders are flying.

How do you know the pilots hadn't briefed themselves on their route and knew what they were overflying. Was the Easyjet in contact with ATC? Did ATC pass this local information to the pilot?

It sounds like you are presuming that this Easyjet a/c was bumbling around class G on it's way to Luton, and not talking to anyone.

[BugOutWest]

The irony of an ex-mil FJ pilot complaining about noise and seemingly also unaware of the "see and avoid" principle in Class G airspace is not lost on me!

I'm not immune to a bit of irony, but the tables are most definitely turned, now, spekesoftly :-) (haven't got the hang of putting the emoticons in the text). There are far fewer FJ mates around now, and they practise more at medium level. And yes, I have had the odd airprox when my lookout was poor (in my younger days), but that was just me and my nav (sometimes) and a puddle-jumper. I'm concerned at the proximity of a large, relatively unmanoeuvrable ac to small, almost invisible gliders.

BugOutWest, for someone who has if your profile is to be believed spent their life in aviation, a lot of it at my expense as I'm a tax payer, I find this to be NIMBYism at its worst.

When you were blatting about yourself making lots of noise in FJs, did you ever spare a thought for the folk you were making noise over? A modern airliner must be much quieter than a 1980s vintage mil jet.

Of course a FJ is noisier, especially one of the ones I flew (it was limited to 450kts at 250ft over land as a result). Of course I spared thoughts for those underneath me, but it was my job and I avoided built-up areas at low level. And in those days, the sound of freedom was enough justification ...

But I live nowhere near an airport, military or civilian so noise from an increasing intensity of airline traffic is of course a concern, especially when I don't believe in allowing the UK to become more of a hub for the rest of Europe.

But that's not my argument: I am an aviator, and as such I believe that the practice of mixing airliners with small GAT or gliders (which, as I said, are nearly invisible) is more risky than necessary. My complaints about noise are minor (a twin-jet at 4,300ft is pretty quiet -- not as noisy as the aerobatter nearby, for instance).

[BugOutWest]

Quote:
the aircraft will drop out of any stack when it can and make its way towards the approach at whatever altitude the captain decides with ATC.
The captain does not decide what level they leave the stack at. The approach controller manages the stacks, gives vectors from the stacks and descends the aircraft. Normally the aircraft will leave the stack at min stack level, FL70 or 80 normally (depending on the QNH)

That is information that I didn't have, that the min level is the min leaving altitude/FL; thanks Vortex issues.

And your points about the NATS consultation makes me believe that NATS should have had you on their PR team, explaining what and how would happen with the new holds for Luton and Stansted. The noise envelope graphics they used were obscure to a great proportion of Joe Public and some of the assumptions/facts that they used were incorrect.

But, we shall see how it goes next time.

It would be good to meet some of you chaps over a beer to discuss it, but this information has been most useful, thanks.

[Roffa]

BugOutWest,

It would be good to meet some of you chaps over a beer to discuss it, but this information has been most useful, thanks.

All the control for the traffic you're talking about is done down at Swanwick.

With your QFI hat on get in touch with the folk down there and bring yourself and some of your studes down for a visit, you'd be very welcome I'm sure.

[BugOutWest]

All the control for the traffic you're talking about is done down at Swanwick.

With your QFI hat on get in touch with the folk down there and bring yourself and some of your studes down for a visit, you'd be very welcome I'm sure.

Excellent idea, Roffa. Thanks

[Grabbers]

Bug out west a fj QFI? My a**e (arse). :O

[Barnaby the Bear]

The writer of this gem is, apparently, a QFI. I am surprised at his lack of knowledge.

I'm not! :}

[10 DME ARC]

Gliders - Radar - In my 28 years of experience a primary radar will show gliders up very well!

[BugOutWest]

Gliders - Radar - In my 28 years of experience a primary radar will show gliders up very well!

OK, now I feel a prat (ignoring BtB and Grabbers). So a controller will be able to deconflict gliders from other aircraft under normal circumstances?

I must admit that I thought that plastic structures would do a good job of transparency to radar waves.

[Vortex Issues]

So a controller will be able to deconflict gliders from other aircraft under normal circumstances?

You would be hard pressed to find a controller giving a Deconfliction service in an area of high activity. They may at best get a Traffic Service and told where there the gliders are ie.

"Big Jet 123, area of high intensity gliding in your 12 o'clock, 5 miles, keep a good look out" :E

[BugOutWest]

You would be hard pressed to find a controller giving a Deconfliction service in an area of high activity. They may at best get a Traffic Service and told where there the gliders are ie.

"Big Jet 123, area of high intensity gliding in your 12 o'clock, 5 miles, keep a good look out"

Thanks Vortex issues, that's all I need.

[spekesoftly]

I'd be cautious in generalising about how well gliders show on primary radar. My experience suggests that some gliders are detected on some types of primary radar.

[McDuff]

I'd be cautious in generalising about how well gliders show on primary radar. My experience suggests that some gliders are detected on some types of primary radar.

Sounds like BoW has a point. It's not a great place for airliners to be, in among the plastic aircraft.

[ToweringCu]

Bugoutwest is right to be concerned about CAT flying outside CAS, in a busy part of the country, at levels used by light aircraft (including gliders). If CAS is available it should be used. Flying over a busy gliding site or aerodrome at these sort of altitudes and speeds, in an unmanoeverable jet is pretty poor airmanship. Airline pilots will not be keeping a good lookout and they are unlikely to be supplied with a deconfliction service (particularly in an area of high traffic density). Gliders do not always show on primary radar and when they do, are often mistaken as clutter or simply ignored by ATCOs. Some of the comments in reply to Bugout (while probably technically correct) show naivety and a lack of appreciation.

[mad_jock]

I don't think many CAT pilots would do it out of choice.

Ops tells you to shift an airframe the IFR flight plan gets submitted a couple of hours slot comes up on it due to flow restriction in an area sector. The aircraft is required 30 mins ago to be somewhere. Crew get told to take it VFR. Its legal so you have to do it or risk having a no tea and biscuits or possibly worse.

Until the ANO is changed so its not legal, it will continue to happen whatever the opinion of pilots or ATCO's.

[fuzzy6988]

I believe that the practice of mixing airliners with small GAT or gliders (which, as I said, are nearly invisible) is more risky than necessary

Could I suggest that the mixing of operations may not necessarily be the problem? I learnt to fly in an environment where many different types of aircraft were mixed with many other types. Uncontrolled airspace almost did not exist - but the freedom of VFR flying was still preserved away from terminal areas.

If the glider and airline are both in receipt of a suitable ATC service, could adaquate separation be performed? The fact that the glider is nearly always invisible on radar may be a problem if the glider issues inaccurate position reports? Or is the fitting of a mode-C/S transponder feasible?

[McDuff]

Could I suggest that the mixing of operations may not necessarily be the problem? I learnt to fly in an environment where many different types of aircraft were mixed with many other types. Uncontrolled airspace almost did not exist - but the freedom of VFR flying was still preserved away from terminal areas.

If the glider and airline are both in receipt of a suitable ATC service, could adaquate separation be performed? The fact that the glider is nearly always invisible on radar may be a problem if the glider issues inaccurate position reports? Or is the fitting of a mode-C/S transponder feasible?

I suspect that many gliders don't have radios, let alone transponders: weight is a major consideration as well as cost.

I've flown in Florida as well, fuzzy, and I know that you mean about the many different types, but there are 2 differences, I reckon: most light aircraft get a traffic or deconfliction service (from what I used to hear on the radio with Jacksonville Centre) and all military are flying IFR, even at low level, unless they're in the range or the manoeuvring areas (TMAs).

[NorthSouth]

Tcu:Gliders do not always show on primary radar and when they do, are often...simply ignored by ATCOsTwo days gone and no ATCO responses to that? - c'mon guys!
NS

[dpo2309j]

> Two days gone and no ATCO responses to that?

No €€€. No incentive. No talk. :}

[Spitoon]

Two days gone and no ATCO responses to that? - c'mon guys!Well, I'm an ex-controller....and bored for a few minutes - will I do?

I spent many years working traffic in a mixed airspace environment (inside and outside CAS, and a variety of different classes) with areas which respectively attracted mil and GA aircraft and gliders. What the controller sees on radar depends on the type of radar and the aircraft characteristics.

One primary radar that I used was excellent at displaying gliders - and anyone with the right knowledge and training could easily be pretty sure they were looking at a glider rather than clutter (just as they could recognise angels, anaprop and other common radar artefacts). And no-one I know ignored the targets that were displayed - they may not have provided a service in an area where there were multiple targets, but they did not ignore them.

This particular radar was not heavily processed and so all of these things could be seen on the display. However, other processing systems typically used today are designed to filter out anything that isn't deemed to be a 'proper' (and I mean no disrespect to pilots who fly things that might not fall into this category) aircraft.

[throw a dyce]

With heavily processed primary,gliders could be partially visible to completely gone depending on the RAG map setting.When they are visible then thermalling gliders look like a windfarm.Single gliders can be mistaken for spurious because the of the low speed and intermittent returns.Some high performance ones like the ASH25 can show,where as the old K8 no chance.
I didn't ignore them.Just vectored the pilot around what I could see,or downgraded the service.If VFRs wanted to overfly the gliding site,then here's their frequency,and the pilot can talk to them.Class G :hmm:

[chevvron]

Easyjet (and other airlines) frequently operate crew-only positioning flights into Lasham airfield for maintenance, this being the busiest gliding site in the country. Sometimes they do a visual approach, mostly it's an SRA, but except when Farnborough is closed ie roughly 10pm - 7am weekdays or 8pm - 8am weekends, they are operating under at least traffic service. If the operators and their insurance companies are happy with this, then BugOutWest should accept it's not an unusual or dangerous situation.

[DFC]

Little aircraft should be kept well away from big ones.

Don't let those pesky B737 or A320s anywhere near an A380. They should have separate airfields and separate zones and only the little ones (B737 and A320) should be allowed to fly over peoples back gardens.

:)

[BugOutWest]

Easyjet (and other airlines) frequently operate crew-only positioning flights into Lasham airfield for maintenance, this being the busiest gliding site in the country. Sometimes they do a visual approach, mostly it's an SRA, but except when Farnborough is closed ie roughly 10pm - 7am weekdays or 8pm - 8am weekends, they are operating under at least traffic service. If the operators and their insurance companies are happy with this, then BugOutWest should accept it's not an unusual or dangerous situation.

That sounds like a good bit of co-operation, chevvron.

I should be surprised if that happens around my neck of the woods, though.

[Lon More]

seems to be related to the Protocol (http://www.pprune.org/atc-issues/413615-protocol.html) thread

[BugOutWest]

Hmmm, since my last post I have discovered radarvirtuel.com. From this I managed to find the flight parameters of an Atlantic Airlines B733 (?) flying on an easterly heading over Gransden glider site at between 2,500 and 3,000ft at around 1632Z today.

I wasn't there at the time, but I saw the aircraft from my garden. It was too far away to be a nuisance, of course, but I was extremely concerned at the aircraft's height -- particularly since my son was gliding at that airfield only a few hours earlier.

Again, flying an airliner in open airspace in the vicinity of gliders which are virtually invisible to radar, and which are very difficult to pick up visually is for me extremely poor airmanship.

Any dissenters?

BoW

[mad_jock]

What exactly do you expect us to do about it Bug?

Current climate of jobs and ops asked me to do it. I would give the choice of doing it or looking for another job along with the othr 1-2k pilots out of work in the UK a good thinking about for all of half a second then agree to do it.

There are quiet a few place round the UK where airliners mix with GA and gliders in Class G. In fact if you wanted to ban it you would cut off the whole of the North and West of Scotland.

Its the company's you will have to speak to/ or make life difficult (through your MP maybe) to get any changes. ATCO's can't stop the practise and for every pilot that refuses to do it there are another 3 who would be quite happy to operate to get a job.

[Talkdownman]

positioning flights into Lasham airfield for maintenance.....do a visual approach, mostly it's an SRA, but except when Farnborough is closed ie roughly 10pm - 7am weekdays or 8pm - 8am weekends, they are operating under at least traffic service.
Don't worry, chevvers, they get a Traffic Service when Farnborough is closed..... ;)

[Jim59]

Hmmm, since my last post I have discovered radarvirtuel.com. From this I managed to find the flight parameters of an Atlantic Airlines B733 (?) flying on an easterly heading over Gransden glider site at between 2,500 and 3,000ft at around 1632Z today.



If the comment above is accurate then the airliner pilots involved are very brave. Gransden Lodge is a notified cable launch site to 3,000' above surface (250').

[BugOutWest]

If the comment above is accurate then the airliner pilots involved are very brave. Gransden Lodge is a notified cable launch site to 3,000' above surface (250').

Well, I've grabbed a snapshot of the Atlantic Airlines track off RadarVirtuel website. Jim59. I'm not sure that it's going to work as a link.

I'm not sure that "brave" is a good way to describe this sort of flight path. He/she might have considered it safe because it was late on a Saturday afternoon. Perhaps Stansted had ascertained that gliding had finished for the day, but I really don't think that an airliner should be there.

BoW

Picasa Web Albums - cmacdb - Airliner tracks (http://picasaweb.google.co.uk/cmacdb/AirlinerTracks#5474375239228726418)

[BugOutWest]

What exactly do you expect us to do about it Bug?

Current climate of jobs and ops asked me to do it. I would give the choice of doing it or looking for another job along with the othr 1-2k pilots out of work in the UK a good thinking about for all of half a second then agree to do it.

There are quiet a few place round the UK where airliners mix with GA and gliders in Class G. In fact if you wanted to ban it you would cut off the whole of the North and West of Scotland.

Its the company's you will have to speak to/ or make life difficult (through your MP maybe) to get any changes. ATCO's can't stop the practise and for every pilot that refuses to do it there are another 3 who would be quite happy to operate to get a job.

You, nothing, mad_jock, thanks. As you say, the company and its captains are the people to convince of the doubtful airmanship of this practice. I have already raised the subject with the CAA, Cambridge CC and a couple of locals. My MP is now SofS for Health, malhereusement, so he will be v.v. busy, but I have hopes of a PQ, nonetheless.

My reason for braving the "lion's den", as it were, was to canvass opinion and to find out what makes good practice as far as professional controllers are concerned. Apart from the odd spurious question about my professional capacity :), it has been a fruitful exercise, thanks to people like you.

B0W

[fuzzy6988]

extremely poor airmanship


You may find that after you fit a radio and transponder into the glider (weight/cost permitting), yourself and others can have a greater awareness of what's going around?

If you're flying in uncontrolled airspace, anything else can randomly fly in it as well. I know it may not come across as something easy to digest.

Powered aircraft pilots (pistons, jets, etc.) could be equally concerned too. I've heard of someone who's been flying through cloud in Class-G and nearly had a glider wrapped around it. You cannot see-and-avoid in such conditions.

A solution is to have more controlled airspace in your area to keep things separated.

But pretty please - no more low-level class A. That kicks me (a non-IR pilot) out!

[mad_jock]

I think you would be shocked to learn how little input Captains would have to stop this practise. Submit an ASR on it get the reply safety assement says its acceptable for none public transport flights.

Another line of attack would be to use CHIRP.

[TALLOWAY]

Well, I've grabbed a snapshot of the Atlantic Airlines track off RadarVirtuel website. Jim59. I'm not sure that it's going to work as a link.



Prove that system is 100% accurate in terms of aircraft position and level please. I suspect it's not.

I have already raised the subject with the CAA, Cambridge CC and a couple of locals. My MP is now SofS for Health, malhereusement, so he will be v.v. busy, but I have hopes of a PQ, nonetheless.

My reason for braving the "lion's den", as it were, was to canvass opinion and to find out what makes good practice as far as professional controllers are concerned. Apart from the odd spurious question about my professional capacity http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif, it has been a fruitful exercise, thanks to people like you.


If you really want to improve safety for all, then I'd lobby them to make Mode S mandatory in gliders, as well as all other aircraft. That way the various collision avoidance systems can do their job and safety is enhanced for everyone. If the country wasn't in such a financial mess, you could even ask the taxpayers for some funding assistance for the equipment ? :O

The only other solution is Controlled Airspace everywhere, but then you run in to all sorts of arguments about freedoms, service provision, costs, access, etc, etc, etc.

Or you can accept that other airspace users are entitled to operate in Class G and that 'see and be seen' applies to all as a method of collision avoidance. Everyone has the right to be there, everyone also needs to apply high standards of airmanship and put away their elitism.

[Sir Herbert Gussett]

This is just nonsense! So uncontrolled airspace is exclusively for gliders? Back to your club house in your 'LOOP' polo shirt, farah slacks with Nokia phone on belt and mountaineering shoes where you can discuss your bizarre perspective with other bad-breathed glider pilots with dirty beards 'till your heart's content!

Uncontrolled airspace DOES NOT mean that it is controlled by GLIDERS.

[10W]

Back to your club house in your 'LOOP' polo shirt, farah slacks with Nokia phone on belt and mountaineering shoes where you can discuss your bizarre perspective with other bad-breathed glider pilots with dirty beards 'till your heart's content!


That also describes a few ATCOs I know :p

[Sir Herbert Gussett]

That also describes a few ATCOs I know :p

Haha! ATCOs are a weird mix! You get some like described then the others that have their lips sealed around pints....!

[jumpseater]

A good few years back I used to deal with noise and track complaints from the public, including people who 'knew' what altitudes aircraft were supposed to be flying at and what altitude they reported them flying at in their complaints. I can't recall a single example of the hundreds of complaints that I recorded and analysed where a complainant stated the height that the aircraft was flying at, was correct. The allegation altitude was always way way too low to that actually recorded. The complainants also included previous pilots and other 'experts' makibng all sorts of assumptions from their knowledge or lack of about what they were actually seeing. The easiest comparison I used to make was with witness reports and how they vary to any given event, a good case being the Biggin Hill Biz jet accident, where despite many seeing it, there was not a conclusive set of witness accounts that gave a reliable picture of the event.

I'd also question the data accuracy of the picture above too, particularly how the altitude displayed is matched to QNH and a whole host of data correlation and verification, not least of which is geographical map, to radar overlay of that specific map and recorded track correlation. Getting those correct is a long laborious process, ask anyone who's done it :ooh: , and involves a bit more than buying a map from a supplier and sticking it underneath a radar track ...

I used to test myself, watching a typical aircraft B737, guess its height over the airfield and then replay the recording. If I got withing 500ft of the altitude I was very lucky, despite doing this many many times. If I couldn't do it accurately, despite being involved in it as my day job, the chances of a 'lay' person doing it accurately are even more remote.

[Charley]

As both a glider and commercial pilot often operating outside of controlled airspace, this is something that I've thought about often. I don't panic or lose sleep over it, but the growing trend of CAT outside of CAS does leave with a increasing sense of inevitable conflicts in the future.

I don't fly airline equipment and the five-ton aircraft I do operate is probably the limit of what I'd personally deem comfortable operating OCAS on a lovely summer weekend such as this one.

Two things;

Easyjet (and other airlines) frequently operate crew-only positioning flights into Lasham airfield for maintenance, this being the busiest gliding site in the country..if the operators and their insurance companies are happy with this, then [others] should accept it's not an unusual or dangerous situation.

Good catch, but does this make the best example of your case under scrutiny? Precisely because Lasham is one of the busiest gliding sites in the country, crews flying larger aircraft surely brief in detail the surrounding lack of controlled airspace and the nature of flying activities in the vicinity. Furthermore, the gliding clubs based at Lasham also do brief their guys when large aircraft movements are expected and the glider-types understand the directions that approaching and departing big iron will take. And they avoid it. And it all works well, just as you say; but it works well because both teams know what to expect.

Compare that with, say, an Air EasyRyan Jet re-positioner flying VFR OCAS. If the route is, say, East Mids to Luton then perhaps there is no need to brief an arrival into a GA field. Only the route. A friend of mine works for one such company synonymous with a particular colour of the rainbow. He once told me a story of how (just as mad jock suggested) he and his captain were invited to ferry an aircraft outside of controlled airspace only to find no VFR charts in the aircraft, only airways charts. Great. They show all the controlled airspace, but they handily don't show where the gliding sites are. Useful that... Naturally, commercial pressure won the day. Not quite the same 'joined-up thinking' and team play of Lasham, I suspect.

:hmm:

If you really want to improve safety for all, then I'd lobby them to make Mode S mandatory in gliders, as well as all other aircraft.

That's all well and good but as previously mentioned on the thread, weight and the lack of a suitable electrical supply on board some types either puts paid to it, or mandates such aircraft out of the airspace. To give you a context; the Ka-6 I used to fly was so weight limited that the pilot had to be more than 9 stone (ish) and less than 12.5 (ish). Otherwise, the aircraft was out of c-of-g limits. Strapping a Mode S and corresponding 12-volt battery into the aircraft would be just lovely, if it wasn't impractical.

The gliding community have been waiting patiently for the much-touted 'lightweight, low-power Mode S' unit that they were confidently told by the powers-that-be "would be developed" by someone along with the rollout of Mode S. Only it never came. So what next? Rule out that sector of aviation from Class G?

Airliners should not be excluded either, far from it. Open FIR for a reason. But all aircraft should be operated in a way which is commensurate with 'see and avoid', if necessary. That means relative airspeed, maneouverability and lookout as required. If certain CAT movements, even positioning ones, cannot be flown slowly enough, or the a/c flightpath altered quickly enough, or if the windows are too small or the cockpit workload too high to maintain adequate lookout, it is encumbant upon them not to go, or to go inside CAS and with the protection it affords them.

Sadly, I fear that at the moment, many large/heavy/fast aircraft operated OCAS may not be adhering to such basic tenets of airmanship. And the "ban/Mode S/geographically limit the gliders" brigade are just pandering to that.

p.s. I think the low-level mil thing is something of a red herring in terms of airprox with gliders. Most fast-and-pointy mil stuff, in my experience, has generally (but not entirely) been well below 'gliding altitudes' or well above it. The most frequent military traffic experienced at soaring levels tends to be rotary. Caveat: in my experience.

[McDuff]

I'd also question the data accuracy of the picture above too, particularly how the altitude displayed is matched to QNH and a whole host of data correlation and verification, not least of which is geographical map, to radar overlay of that specific map and recorded track correlation. Getting those correct is a long laborious process, ask anyone who's done it , and involves a bit more than buying a map from a supplier and sticking it underneath a radar track ...


Yes, it is very difficult to estimate heights, but ADS-B readouts are from the transponder, I believe, which uses 1013 as the datum, so where is the difficulty with that, on a standard day?

McD

[zkdli]

Aha Mcduff,
What was the pressure at the time that the aircraft was flying over head? If it was today or yesterday i would wager that it was higher than 1013.
I wont give any clues on how to work out it's true altitude we will have more fun arguing over that for the next couple of days:O

[BugOutWest]

Well, zkdli, the Chatham was 1025 on Friday, I seem to remember, so that's about 12mb difference; at sea level that would be in the region of 400ft. But that's immaterial, really, since it was below 3,000ft over the glider site and it *looked* low.

But if you have a cool method of calculation, do tell ... ;)

BoW