Flying Airways in the UK?

[12Watt Tim]

IO540

Single-crew, various piston twins. Didn't answer about the speed, but generally between 160 and 180 kts TAS.

Try it in an aircraft cleared for known icing. Most of the time ice will clear somewhere below -2 degrees. Most of the time even below zero in cloud you won't pick up ice. I know what the books say, I know plenty about the theory, but as always with science there is nothing to beat a test, and I've been there and seen it.

Remember also that if the surface temperature is that low then the temperature at FL100 will often be so low that icing will not be that bad.

Which bit of the world?

Europe. Mostly western and northern, but some into southern and central Europe.

Let's say you get a DCT BCN (Barcelona VOR) from 250nm away. How would use use a KNS80 to do that? (I can see ways but not easy)

You ever actually do a comms exam, and learn the expression "unable"? You never have to accept a clearance. However I was pretty good at it, and would usually be able to accept. Various methods, easiest was to use a nearby navaid to define BCN as a waypoint. Works with Brecon too!

Islander2

Then we can only assume that you never flew in European winters or over mountainous terrain!

You would assume incorrectly. I found icing to be exceedingly rare at FL60, rare at FL90 and 100 which was my more usual territory.

[Islander2]

You would assume incorrectly. I found icing to be exceedingly rare at FL60, rare at FL90 and 100 which was my more usual territory.

Then for inexplicable reasons, our experiences do not coincide!

[12Watt Tim]

If you were flying Islanders I suspect you were flying rather lower than I was. I would only go lower to clear ice I was suffering higher up, but at FL100 I was rarely in cloud.

[IO540]

12Watt Tim should go for the Nobel prize in physics.

But yes one can get away with a lot if flying a substantial deiced plane, especially at 160-180kt.

And one gets away with a lot anyway, due to the statistical nature of weather. Then..... something comes along and bites you

You ever actually do a comms exam, and learn the expression "unable"? You never have to accept a clearance.

No, never heard of it

Have you heard of BRNAV and FL095? Your flight would have been illegal at

FL100

if unable to do RNAV.

[S-Works]

You would assume incorrectly. I found icing to be exceedingly rare at FL60, rare at FL90 and 100 which was my more usual territory.

Then what exactly were you flying a rocket or MS FS?

I have just flown to Spain and at 18,000ft it was MINUS 35c and I can tell you as we were climbing through all that cloud we were icing and that was at Turboprop climb rates. I have iced this morning flying, started picking it up around 6,000ft and not stopped until clear over the top.

[IO540]

wonder whether it is a cause or consequence or both, of the lack of a Class E system, that fewer smaller planes fly in IMC.

I think that is just the way light GA is. The vast majority is VFR-only and I really mean VMC-only; pilots who are st scared of entering a cloud (which, as an old hand might point out, is just as well ).

There is a small hard core who do fly in IMC; these comprise of pilots who have an IMC Rating, or an IR, or neither (but probably did have one or the other but it has lapsed but they still have what they judge are the skills and an appropriate equipment).

I am pretty convinced the whole European private IR population is of the order of 2k pilots, plus probably a few k IMC-R holders in the UK, and if you work on say 100hrs/year (which itself is about 5x the UK VFR pilot annual average so I am being awfully generous) is a really small chance of one being airborne anywhere near your bit of the cloud.

On top of that, pilots who fly in IMC are for the most part not cowboys and they are going A-B and not for the view (obviously there is no view) so will probably not be flying at 700ft AGL. They will be at a few thousand feet where there is close to zero VFR (VMC) traffic anyway.

The statistics support this, with zero mid-airs in IMC in living memory.

I'm starting to buy-in to the assumption that flying IFR in IMC in Class G will probably be fine for now, due to lower levels of traffic. But until a few mid-airs happen, probably nothing will change.

I don't think that the (nonexistent) mid-air data supports any belief that one of them is going to happen anytime soon.

The existence of Class A airways suggests Big Sky Separation doesn't always work for higher density, faster moving, mainly commercial traffic.

As the old joke goes, ATC pack them in tight into narrow corridors and then work hard to stop them hitting each other

That's just the way the aviation world has developed over the decades. It probably came from navaids, which gave rise to airways (VORs are the perfect "old" solution for flying long legs, but they work only if you are flying between two of them).

The airways in turn gave rise to controlled airspace, and that in turn has been kept tight by all kinds of other interests: the military, GA, the need to provide an expensive radar service in CAS thus creating an incentive to keep it tight.

With separation offered if you have a plane which flies high enough to do it in, and only on a best effort basis to everything else which flies beneath, this setup contrasts greatly to the rather zealous "health and safety" culture which exists on the surface.

Sure.

While a risk still remains, I guess the plan for now is to climb to VMC on top and enjoy the view

Indeed

The catch is that UK CAS is generally too low to enable one to do that unless they have an IR and are on a full IFR flight...

Emotionally, the risk is hard to accept, because it means a virtually certain death if your number comes up. I can't suggest a way to get one's head around it, other than (again) to consider the stats.

The midair stats tell you very powerfully how to get yourself killed in a mid-air:

- fly below 1000ft (the best way)
- fly in areas where traffic is packed tight (the circuit)

Some traditional ideas, e.g. not flying across VORs but flying a shortcut instead, are not supported by the stats. I guess it may be because so few pilots are radio navigating and those who are are not going to be flying low, because they planned the MSA and are sticking to it.

[Pace]

10540

I really must stress it is not just a few piper warriors bombing around in IMC OCAS.

Fly airways to LondonDerry in Northern Ireland and you will be met with the fact that once away from Belfast you are OCAS and soon after with NO radar coverage.

I can well remember flying in there solid IMC from 12000 feet on down to a 700 foot Cloudbase there were four of us all at different levels in the hold while the first was on finals after flying the pilot interpreted approach.

The rest of us were all talking via the controller to each other checking our revelant positions. Below me was a 737, above me was a passenger carrying turboprop.

I take your point that the big sky principal appears to work. I take your point that the worse the weather the less the traffic and the more experienced the pilots (usually

Because it hasnt happened doesnt mean it wont happen and then it will be CAS nearly everywhere after the media have a field day.

Pace

[IO540]

Agreed; there is also the Islander type traffic there which cannot go high because they are unpressurised and have no oxygen. In fact some of these get up to all sorts of things like scud running across the Channel at 400 ft

I don't think that an OCAS midair would bring a lot of CAS. I think it would possibly force the CAA to ban OCAS public transport ops though. Whether such a move would be successful I don't know because it would instantly terminate a lot of AOC/PT ops which pay fat (think "737-fat") AOC fees to the CAA..... The CAA has been extremely reluctant to take action against anybody who pays it big fees.

So nothing would probably happen.

I don't think widespread CAS would happen because of objections from the military, and what voice GA has (not a lot), and the cost of providing a radar service all over it, and the service would have to be provided because one could legitimately file IFR routings anywhere within it...

A possible outcome is a huge TMZ but that wouldn't bother anybody flying at the relevant levels.

It might even have another positive outcome, like forcing EASA's hand in relaxing its dead slow certification process for ADS-B which would pave the way to cheap TCAS for everybody.

[IO540]

I also don't know why GA will object to CAS if it means greater safety for everyone else.

Because (a) the safety is 99% illusory and (b) there is no assurance of getting entry and (c) nobody wants to pay for the radar service to the traffic flying over a larger area (any perceived safety gain comes from traffic separation).

As far as GA is concerned, the present operation of most CAS (below Class A) is an abuse of the ICAO airspace classification, especially as quite often there is no obvious reason for the denial (I am talking about Europe, of which parts are "the 3rd world"; not UK specifically)

As far as ATC are concerned, denial of a transit is what CAS is about If you did not have that option, there is no point in having it.

The thing is that different systems fit together differently with that country's practice elsewhere. For example, the UK's widespread Class G fits well with the privatised ATC (which doesn't want to provide a service to anybody unless it's mandatory) and with the ability to fly IFR non-radio. The French (and American) extensive Class E airspace works well with their centrally funded radar services.

We are not going to get a US-style Class E and radar services (incl radar controllers covering non-towered airport GPS approaches) here unless ATC is re-nationalised; simple as that.

[Pace]

10540

the trouble with the theory of its never happened before so never will is a dangerous policy to take.

Take what happened with the gun laws.

The policy that it nver happened before does not equal it will not happen.
A lot in our society revolves around liability and duty of care.

To have a lump of airspace where a 737 is descending in cloud with 200 pax OCAS and mixing it with Gliders in cloud, microlights hang gliders etc is really a game of Russian roulette.

When the media hit on the reality of what is allowed to go on the Sh+t really will hit the fan especially when it reported than non instrument trained pilots with non instrument equipt aircraft and no transponders had a collision with a 737 ????

IFR traffic will want CAS from takeoff to touchdown. Look what happened to the airspace around Robin Hood Donaster there are plenty of airfields like that.
I am afraid that light GA does not figure as important when it comes to airspace distribution and will be relegated to airspace that no one wants.

Pace

[Pace]

Fuzzy69

I am not taking a holier than thou attitude as I have and do operate OCAS in anything from a twin up to business jets.

In the past I have used an IMCR in anger and sat there with no radar coverage in solid IMC now its an ATP.

Up until my near miss with a glider in imc I too trusted the big sky theory. Now I am slightly more aware.

I must admit to relaxing the higher you climb OCAS especially in the business jets as you are travelling a lot faster.

I must admit in another thread I was surprised at the lack of support for compulsory use of transponders with altitude in IMC and fear that unless we govern ourselves someone in the future will do it for us.

Pace

[IO540]

Sorry IO540, what do you mean by this?

In the context of IMC mid-airs, and CAS, and radar services, etc.

I thought CAS was established to provide separation to traffic.

Separation within CAS is done by radar, or occassionally (e.g. over Africa) procedurally. But this is only within CAS. OCAS, traffic can do what it likes, including flying into CAS...

Transit ought be granted where traffic conditions allow.

I agree

I also agree (obviously) that a widespread radar service OCAS should be provided. The problem is that you have to do this within today's privatised ATC system, so it isn't going to happen - ever.

You can achieve TCAS today. The system costs £10k-£20k depending on details, and usefully shows up Mode C transponding traffic. The plane needs to be dismantled to a large degree to install most of the antennae and to move all existing antennae off elsewhere (seats out, trims off, etc). 2-3 weeks at the avionics shop and that assumes they are competent. I looked into this a while ago; most avionics shops could not be bothered to even quote on it, and I decided that the upheaval was not worth it since many people in aircraft maintenance cannot even refit trims properly.

As regards hitting an airliner, any large PT aircraft has mandatory TCAS already so if you always fly with Mode C on (which you obviously should) they will be able to avoid you using this last-resort means.

Given currently mandatory TCAS on CAT, I think the whole risk of a GA-on-CAT mid-air is with nontransponding (or Mode A transponding) GA, which has a simple technological solution: make Mode C mandatory Now, how long a thread do you want on that one?

[TALLOWAY]

If we're paying taxes for the aviation sector, it sounds fair that it should be spent on developing aviation infrastructure, such as a Class-E system, free landing fees, and cheaper CAA fees.

If only that's how it worked in the UK but the Government pays not a penny from it's aviation taxes to anything within aviation. The CAA and NATS, although different types of company (one wholly government, the other part government- part private), are both expected to pay their own way and cost the government nothing. Indeed Nu Labour will probably sell off a good portion of their share in NATS come the end of January. They don't care about the public and the infrastructure we deserve. They care about lining their pockets and trying to patch up their shocking economic policies.

As a further example of their greed, they are even looking to charge frequency useage in the aviation band, regardless of the fact that it is primarily for air safety.

politicians. I'd shoot every last one of them.

[debiassi]

Remember also that if the surface temperature is that low then the temperature at FL100 will often be so low that icing will not be that bad.

Not quite sure what your saying here? Do you mean if its cold at the surface then ice at fl100 wont accrete on an airframe???
Lets say its plus 2 at the surface and ISA exists so lets round it up from 1.98 to 2 degrees x 10000ft = -18c Lets then add a cluster of cumuliform clouds with vertical development from 3000ft to fl110. At -18 and when considering that the majority of moisture would be towards the top of the clouds, then I would say that icing at fl100 would be a very serious threat.

[CMS]

At -18 and when considering that the majority of moisture would be towards the top of the clouds, then I would say that icing at fl100 would be a very serious threat.

I was taught, when I did my US IFR, that airframe icing could only occur between 0°C and -10°C. At -18° icing should not occur.

Was this wrong? Or is it different in the UK?

Cliff.

[A2B Ferry]

I was taught, when I did my US IFR, that airframe icing could only occur between 0°C and -10°C. At -18° icing should not occur.

Was this wrong? Or is it different in the UK?

You were taught wrong but fortunately all is not lost. Ice will usually attach to an airframe in the temperature range of +2 through -20c. Although it is possible for icing outside this temp range, it is unlikely although the only physical limiting factor number is -40c and there must be visible moisture in the air in the form of cloud, freezing rain supercooled liquid etc.

[debiassi]

I was taught, when I did my US IFR, that airframe icing could only occur between 0°C and -10°C. At -18° icing should not occur.

Was this wrong? Or is it different in the UK?

He definately steered you wrong on that one Cliff. The temperature range for icing is the same anywhere on the planet and the numbers for operational terms are positive 2 to negative 20. The study theory always states that icing is possible on the colder side of the scale with negative 40 as a physical limiting factor but outside of the +2-20 temp range, icing is unlikely. I have seen some theory that state zero through -20. May be its something to do with the wind chill factor on the leading edges unless of course your flying at concord speed in which case heat is generated.

[mad_jock]

Well there must be something weird going on over the Cairngorms then. Because I have had ice shedding off the props at -30 and building on the wings.

Why would you want to muck about with icing anyway?

Its not just "look at that" we have picked up a bit of ice.

When it starts building fast it really does lump on. In under a min you can boots banging away ice clattering off the hull off the props airframe vibrating like a bugger. I avoid it if I can and I have over 2000 shp to play with, pneumatic boots and prop heaters. I have still had my arse twitch a couple of times flying around the highlands due to icing and I know I am not alone.

[debiassi]

Well thats relatively easy to explain really. If you have picked up ice on the way up and your flying into colder temperatures then its unlikely the ice you picked up is going to sublimate in a hurry. Simple as that really, not sure of the point you attempt to make?

Well there must be something weird going on over the Cairngorms then. Because I have had ice shedding off the props at -30 and building on the wings.

[mad_jock]

That ice can form on the air frame at -30 when you enter cloud.

The profile of the flight was up the old W3D at FL180 remained high and when started dropping the height off for the direct arrival within about 2 mins we had about 1 cm of ice on the wings and ice shedding off the props. When we landed we managed to get a 1ft high for want of a better word vase off the spinner about 1 cm thick.

When we departed it was CAVOK down south, no ice in the climb.

If the de-iceing gear isn't working the plane gets grounded if there is cloud in the sky and the temp is below 5 degs above MSA. And yet it appears to me that some people are saying its ok to play a numbers game flying in cloud with no de-icing gear? Its utter madness.