I interpreted your comment:

as suggesting that the other aircraft wasn't flying to the rules. But I take your main point.


WCollins wrote:
I heard of a proposal many years ago that the big hand on the altimeter should match your heading (e.g. NE at 1000s + 125 ft). It provides only 500 ft of separation between opoosite direction, but it seems to meet sensible criteria. Perhaps we should add a die to the requirements of Scehdule 4 :)

Finally, IO540 wrote:
It's a good question. One way of looking at it might be to consider a flight 1 from A to B taking 2 hours at 150 kt, and a flight 2 from B to A, taking 3 hours at 100 kt. They will pass if the difference in their departure times is in a 5 hour window (i.e. if 1 leaves at 1400, it will conflict if 2 departed between 1100 and 1600). If you reverse flight 2, it will conflict only if it leaves in a 1 hour window (1300 to 1400).

While that's a 1-dimensional look at a complex problem, but I think it illustrates the point.

bookworm

That's an interesting way of looking at it. I am not qualified in this field so better not say any more, but I feel that a better way to look at it is to start with an assumption that two planes are already inside a sphere of a given radius, say 1 mile, and work out if they are more or less likely to hit depending on the rules they follow.

Anyway, the French use the semi rule, which appears to discard half of whatever advantage there is.

Like the Dice Man, you mean? But he ends up raping and murdering and all sorts of terrible things, then I gave up reading it in disgust.

Actually, going back to Woss' original point, maybe we should make the VFR/IFR choice based entirely on the throw of a die :ok:

Will

THIS IFR?VFR QUESTION........
 

Is this departure IFR or VFR? That is the question!


And the answer is ....................er............somewhat ambiguous!


Very many versions exist of ICAO/ATC or CAA/JAA regulations from the ANO/AIPs.


The AIM does a good job of collating all the relevant Air Law material to give the private pilot a good point of reference for all Air Law/legislation issues, but it does not seem to go far enough. It could be a little more coherent.....with an INDEX too!

I can't remember which poster said I should stop quoting my ATPL material and look at the rules, what are you on about?

If you KNEW I was wrong just say it and quote me the ANO/AIP/JAR/ICAO Doc reference and I will go and look it up!
My JAR/CAA Approved ATPL course has to be kept up to date and correct, ratified and inspected regularly by the UK CAA.

The school I use was inspected while I was there in OCT 2003. Why would the CAA let such a closely monitored and regulated organisation diseminate incorrect information?


I quoted (in good faith) the ICAO based JAA approved notes saying that VFR departures should not be made with

a) cloubase less than 1500ft (aal)

b) and vis below 5000m

In CTR/ATZ or traffic patterns

The 2002/2003 AIM says (and may now be out of date)

AIP 4.1.1.2(pg 274)

the minima for SE aeroplanes should be adequate to ensure a HIGH PROBABILITY of a successful landing being made should engine failure occur after take-off.

It goes on to say that minima for commercial ops is 1000ft cloud ceiling and RVR 1800m as another poster quoted earlier.


I am not trying to tell the original poster that he took off illegally or anything such. What I am trying to tell others who may be reading and of less experience (ie PPLs or recent IMCs) that caution is the best option and that was the basis of the scenario in my previous post. EFATO SE in IMC after declaring a VFR DEP then entering IMC shortly after takeoff.

Taking off "into-the-soup" VFR (then IFR) at an uncontrolled airfield with no flightplan is foolhardy at best.

A better example should be being set to the other low hours PPL/IMC pilots on the forum whose last guidance was their flying instructor.

Just think how you might explain the loss of an aircraft/freind or loved one after taking off in marginal conditions. The CAA seems only too happy to prosecute these persons these days not including the personal injury fraternity.

If in doubt and the ATC or a more learned aviator says....DON'T.

Then don't. Caution=best option.


Regards

Tropo

Ps Happy New Year to you all!!!!!!!!!!!!!

That would be me, and what I was on about was that you should stop quoting your ATPL material and look at the rules.I did that, though it is not in my nature to be didactic and brusque, so I put it rather more nicely. I told you that I had scoured the ANO and RotA and there was no reference to the figures you quoted. I was even helpful enough to give you links to the relevant legislation so that you could check for yourself. The trouble with my quoting chapter and verse is that the rule you mention just ain't there. What if I told you that there was a law that brown poodles may not go into Royal Parks on Thursdays, and when you said that you could find no such regulation I said "If you KNOW that, then quote the regulation."?It is how many, many IFR flights take place. GA is strongly discouraged from using the big, grown up airfields which are connected to controlled airspace, and ends up in the Fairoaks, Blackbushes, Elstrees and Biggins of this world, from which there is no "right" to a radar service, it is only available in the gift of controllers at Farnborough, Luton or Thames, if they have time. As you would be told if you went onto the ATC forum, an FPL is of almost zero safety value outside controlled airspace.

It is great that you have so much faith in your ATPL course notes, but I fear that you will find, once you have been out in the real world for a bit, that it is not as black and white as the printed page.

Will

I think part of the ambiguity of deciding whether to fly VFR or IFR comes from the airspace system. If the airspace was set up to facilitate easy and safe IFR flights, and flight plan filing by GA pilots using an IMC rating, then it would take much of the uncertaintaty out of whether one should fly VFR or IFR, which would increase safety and help the pilot in his/her aeronautical decision making process.

Heres and idea......why not re-label all airspace (within reason) above say FL50, and below FL100 Class E, so an ATC clearance while operating under IFR could be given.....No clearance would be required for VFR flight. Overhead 'busy' airports, this Class E could become Class D, so ATC clearance would be required for VFR flight. Existing Class A low altitude airways could be re-labeled Class D if it were to make people happy, then at least VFR pilots could enter under control of ATC......

While we're at it, employ more ATC controllers, link all the radar data from military installations and civil stations and pipe it into one room in the south, and one in the north (lets call them London Lower Airspace approach control and Scottish Lower airspace approach control), and hey presto every one is happy :D

Am I getting carried away? :D

CU
EA

Only with the thought that anything might actually happen :p

It is great to campaign for more expenditure on ATC infrastructure, but the fact is that ATC is now (in the UK) an almost exclusively commercial matter, and I cannot see NATS and SERCO tripping over each other to bid to invest in control systems and controllers to handle what will be almost exclusively non-paying users (because they are below 2T).

If you impose charges on all IFR flights (of whatever weight) you will find that the majority do as I do and fly in such a way as to mitigate or eliminate charges (in your model that will mean below FL50) thus reducing any income to the service provider.

Will

What, and actually use the different classes of airspace for what they were intended??? :eek: :eek: :eek:

It'll never happen.

FFF
---------------

Not long now in any case before ICAO moves on from the A-G airspace classification system and into a simpler model.

It'll be interesting to see what the DAP makes of that in the context of the UK's airspace system.

2D

It'll be interesting to see what the DAP makes of that in the context of the UK's airspace system

Make it all "N" :D

Are you flying Saturday, 2D?

2Ds, I'll let you know in a couple of weeks!

I'm counting on it! Good luck with the job :D

2D

Do you know roughly how it'll be done, 2Donks?

tKF

Its a long way off tFK, but in essence it is proposed to divide airspace into areas of "Known Traffic" (Class K) and Unknown (U).

The implications for separation adn control in class K are clearly somewhat different to Class U. Much more than that varies somewhat depending on where you read it. The bottom line is

- fewer airspace classes
- greater harmonisation of ATC service
- less confusion.


Worth holding you breath for perhaps ;)

2D

Troposurtfer,

The ICAO requirement you quote requiring 1500ft ceiling for VFR flights only applies within control zones. The logic being that since under ICAO, you may not fly lower than 500ft AGL and in controlled airspace you must be 1000ft vertically from cloud, it would not be legal to depart VFR unless you could both reach 500ft agl and be 1000ft below the cloud. That is ICAO, not UK which does not have the same 500ft ASFC requirement or the 1000ft vertically from cloud requirement in the lower controlled airspace.


Getting back to the priginal matter;

Logically, I think....who in their right mind would depart VFR into such conditions.

There is no reason for not departing IFR. Even if one wished to remain "visual" until a radar service was established, there is absolutely noting wrong with departing IFR but remaining visual...check out IFR minimum height requirements and the exemption for being visual below 3000ft etc.

To look at the situation from a post accident point of view, a review of the decision to depart VFR and then soon after fly IFR would place much emphasis on the prior planning made by the pilot and comparing the actual point of entry into IMC with the planned point of entry into IMC.

Looking the the situation from the "other VFR pilot" point of view........can one honestly say that two VFR flights in such conditions could if they saw each other in good time, manoeuvere suficiently to comply with the rules for avoiding collisions while at the same time remaining VMC?

It is the same as driving down a twisting busy country road at 60mph...where the legal speed limit is 60mph......but one would be deemed reckless to drive so fast.

Regards,

DFC

At least two have been given earlier in this thread.

All these big "reckless", "foolhardy", "dangerous" words are simply silly. In the real world of departing an airfield that is not in a CTR and doesn't have radar there is absolutely no difference in the safety of departing VFR or IFR. Known traffic only extends to 2.5 miles from the ARP, there could easily be unknown traffic crossing the take-off path whichever set of rules you declare.

I fear that there is a considerable amount of prejudice and a considerable lack of knowledge and experience being shown in this thread, some from people who equate IFR with controlled airspace and some from people who haven't got there yet.

Maybe we can tone down the accusations if we want a reasonable discussion.

Will

CAN you depart "IFR" from a non-ATC airfield, anyway? You can't be in receipt of IFR departure instructions, for a start.

The originally described scenario is perfectly OK for a departure, whatever one calls it, provided the pilot is capable of instrument flight. If not, he almost certainly won't get very far.

The additional risk (relative to departing from the same place in say a higher cloudbase) is that in the event of a SEP engine failure one won't have much time to look for a field. I departed from the Scilly Isles once in probably 200ft cloudbase but there is only water at the end of the runway...

Yes.

It is not mandatory to be under a clearance to operate IFR outside controlled airspace. If the departure is made, remaining clear of controlled airspace, then the fact that the A/G Operator cannot give you a clearance is neither here nor there.

The Rules to be obeyed under IFR are set out in the Rules of the Air.

2D

2Ds quoth: ...but in essence it is proposed to divide airspace into areas of "Known Traffic" (Class K) and Unknown (U).

I thought the "known traffic environment" would be class "N" - hence my comment previously :O

Rustle

You may be right. I have documents here that call it numerous things :D

I felt more comfortable defendning the choice of the letter "K" when describing a concept spelled "K N O W N" though.

It was my understanding that N was Intended Traffic Environment and that U was Unknown.

2D

IIRC N is iNtended, in other words ATC not only knows about the traffic but knows its intentions, for example from Mode S enhanced data.

It seems you two could be right :O

Just had a look at the PPL/IR Europe mag:

http://www.pplir.org/journals/old/InstrumentPilot34.pdf

(page 15)

Which, whilst not authoritative, is informative :D

Since it is an old issue of "Instrument Pilot" non-members can download and read it

AFISOs can, and very often do, read IFR clearances issued by London Control.

You can take off from a farmer's strip IFR, fly 200 miles IFR, and land in VMC at another strip without ever mentioning it to anyone, whether by FPL, telephone or radio, providing you remain clear of regulated airspace.

And remember a few things before we have more expletives about such a trip:

IFR does not necessarily imply IMC
The need to fly IFR might be that you are flying at 500' below a 4000' cloud base in 30km vis (that's IMC!)
Even if you are fully IMC all the way (except the first 500' and the last 1500', say) you are statistically infinitely less likely to have a mid-air than someone else doing the same thing VFR on a gin-clear day.

Will

2donkeys / wcollins

Interesting - I didn't know that you get the non-ATC airfield radio operator to telephone London Control (or who-ever else). That's news to me. What if it is a farm strip? You presumably call them yourself.

Of course none of this means anything safety-wise because at best one is going to get procedural separation from known traffic. In a free for all airfield you won't get even that.

So, given that departing "IFR" is likely to mean absolutely nothing, why not depart VFR and change to IFR on the first call to the proper ATCU? I suppose having a pre-assigned squawk saves a bit of time :O

Having been to plenty of free for all airfields, I think the chance of a collision in the conditions described is far less than on a clear day!

It's been an interesting debate on terminology :O

The normal procedure for an airways IFR departure from an uncontrolled field, does not vary much.

If the field is A/G or FISO controlled the clearance will often sound like this :

"London Control instructs N33NW to remain outside controlled airspace, squawk 1234, and to contact xxx.xx when ready"

Where the field is a farm strip, you could telephone for some sort of clearance, but it is more common to take-off and use either London Information or a local LARS/Radar unit to negotiate your entry into controlled airspace.

Getting a clearance straight into controlled airspace from the ground under either set of circumstances is vanishingly rare because of the airspace that such a clearance would tie up. This is despite it being common practice in the US with its somewhat different airspace structure.


Whether you deem yourself to be IFR or VFR before receiving your clearance into controlled airspace is a decision you take based primarily on the prevailing weather conditions.

2D

2 Donkeys has it spot on and London Inf or the likes of Thames and Farnborough are always very helpful an efficient in activating flight plans in the absence of ATC at an airfield.

The main reason for not leaving VFR and transferring to IFR is that you will save a hell of a lot of radio time if you don't have to file an airborne flight plan. It is better to have it in the system before you leave. (You can fax it to Heathrow or similar and then call them to check it is in before you take off).

The issue, in the weather conditions described, is to get a radar service as soon as you can after departure whether it be RAS or RIS. If you are leaving from an airfield that is not within range of a suitable station then you have to take the chance whether you are VFR or IFR

The latest Occurence Reports mentioned an incident in the Scottish TMA where an aircraft had got airborne from an uncontrolled airport with an IFR flight plan and entered class E airspace without a clearance. IIRC the weather was VMC -- I'm not certain if the aircraft entered class D as well, which would change things substantially.

Interesting situation. Is it OK to simply "maintain VFR" in class E until you get a clearance, even though ATC knows of your intention to be IFR? What's standard practice in the US? Do you file a VFR/IFR flight plan for that, or just file IFR?

(Of course it's irrelevant to most of what we do down south in the absence of class E.)

The US position is somewhat different in that at uncontrolled fields, it is usual to call the center on the phone to receive a clearance (with a clearance void time) prior to departure. In this way the situation doesn't occur.

In the case where this is not possible, IFR flights (on IFR Flight plans) must remain outside controlled airspace unless cleared. In the case of class E though, once two way contact has been achieved (defined as an exchange of callsigns) entry is permitted without a specific IFR clearance. VFR flights require no particular formality to enter class E.

If you are filed on an IFR flightplan, and elect to enter Class E claiming to be VFR, this will cause confusion and potential embarassment...

2D

Despite being a PPRuNer for a good while, I still haven't learned how to quote properly. So forgive my home made version please.

2 Donkeys said:

This depends very much on which part of the country you fly from and which controlled airspace you want to enter.

I fly from Bourn, Cambs. There is generally no problem in entering the local Class D (Stansted or Luton) on an airborne flightplan. The problem comes in trying to get into the TMA.

The difficulty (as I understand it) is that, even having filed and activated an IFR flight plan, the TMA controllers will not have a flight progress strip come out of their computer for the flight and will be therefore unwilling to accept the flight. The Luton and Essex controllers rarely have the time to solve this little problem for you. (Bourn is about 7 miniutes from Class D and about 8-10 minutes from the usual Class A entry points). This time is not enough to call London Info to request and obtain a clearance without orbiting outside CAS for an uncertain time.

So, what about telephoning before take off? For one flight, as luck would have it with a TMA controller sitting in the right seat, he tried to get the flight progress strip out of the system and onto the Essex or Luton controllers' position by phone before we departed. He succeeded, but it took him two or three calls over about 15-20 minutes and I think his success was more due his intimate knowledge of the system and who to talk to than anything else. In other words, not a method open to the average pilot. Even then, the Luton controller was not expecting us.

That leaves the third alternative, telephoning a local ATC unit (not the uncontrolled departure field) before take off and asking them to prepare the ground for you, so you can get the clearance soon after becoming airborne. I don't believe you have any right to such a service and you are relying on their good offices and other workload and priorities not interfering.

I would say it's an unsatisfactory situation for all concerned, pilot and controllers.

AA.

I think that is the nub of the issue. My examples above made the assumption that the intention was to depart IFR into the airways system, because simply getting an IFR clearance into class D is not a particularly onerous task.

The workload associated with negotiating your own clearance is not trivial and can involve you flying, if not orbitting outside controlled airspace for some time. This makes the UK somewhat unique in requiring IFR pilots to carry VFR charts with them - just in case. UK-based pilots may cope with this adequately. There are many horror stories of foreign pilots struggling badly when their "clearance" contains the line "remain outside controlled airspace". Hard in a C182, very hard in a Citation.

It is a pity that the airspace is too busy and too "uniquely" designed to permit the widespread use of US-style "void after" telephone IFR clearances.


2D

Being told "Remain Outside Controlled Airspace" is not a clearance. I fact it is reinforcing the fact that a clearance has not been issued and one must not enter controlled airspace.

On the Class E issue, Once can enter under VFR without clearance and must remain VMC at all times. If IFR then one can not enter without clearance. So, if departing into or towards class E, if one decides to depart VFR and pick up IFR enroute, one must remain VMC until ATC issue the IFR clearance.

That is diffeent from the Class G case which started this all off...where in the case of say the London TMA, one can continue IFR remaining outside controlled airspace until such time as a clearance is issued.

One point to remember with regard to the London TMA is that if one decides to continue enroute below the base awaiting IFR climb, this can in some cases complicate matters because the flight while not in receipt of a clearance will be moving from sector to sector thus slightly complicating the coordination process. Thus it can at times be easier if the flight holds while awaiting clearance...although this varies from situation to situation and from day to day.

However, what must be remembered is that for an IFR flight intending to enter controlled airspace, a SLOT may be issued by CFMU.

Going back to the flight departing and remaining in Class G, as W Collins correctly says, one can be IFR for a number of reasons and provided that one complies with the minimum height rule in descent towards the destination can be FIR from farm strip to farm strip non-radio.

I also agree that possible with the exception of some choke points below the London TMA, one is more likely to have an airprox in VMC than in IMC.

However, the rules require that except for a local flight the combination of forecast and actual weather must show that the flight or portion of flight can be completed in VMC if the flight departs VFR. If the end of the VFR segment is dependent on receipt of a radar service which is not guaranteed, where is the end of the VFR segment?

There would have to be some point where the pilot would say...if I don't have a radar service by XXX, I'll turn back.........however, given the conditions, is a safe VFR return guaranteed?

One can depart IFR from any aerodrome. Remember however that the relevant part of JAR-OPS applies to all flights and sets the weather minima!!

On flight planning...don't forget the Z and Y flight rules!!

Regards,

DFC

Good summary DFC. Which question were you answering though?

2D

DFCOf course, one reason that fewer airproxes are reported in IMC must be that we may be totally unaware of them :O

Which is why I think that it is more helpful to talk in terms of collisions than airproxes. As Vintage ATCO (I think it was he) said a couple of days ago "a miss is as good as three miles!"

I wonder though, whether the choke points are any more dangerous in IMC than VMC.

I fly between OCK and BIG in VMC on weekends from time to time and it's horrific. Sometimes there seems to be more metal than air.

I don't know if, in the early days, it was easier to see other aircraft than now, but in the present mixed traffic environment in the Epsom area, with 250kt bizjets, 180kt twins, 120kt singles, 100kt rotaries, 80kt singles and 40kt microlights the chances of seeing other aircraft seems to be small. I often fly with two or three other pilots and we all miss seeing something until it zooms past.

What I rely on, and believe to be true, is that the number of people who are flying in Class G and who would choose to be in IMC is considerably less than those who would choose VMC, or not fly at all if VMC is marginal or unavailable, which is why I am happiest in the choke points in IMC rather than VMC. However, I take the precaution of not flying at an exact multiple of 100s of feet (2250 would be typical in the Epsom/Dorking/Guildford area) and I avoid passing through beacons, preferably by a couple of miles.

Will

2D

My examples above made the assumption that the intention was to depart IFR into the airways system

In which case, surely, one needs to file an IFR flight plan, via Brussells, 3 hours before the flight.

It is true that in order to fly an IFR flight in controlled airspace, Brussels needs to get a flight plan. 3 hours is a little extreme, and most flight plans can be turned around inside an hour if you have take the trouble to pre-validate the route.

However, if you are implying that having a flight plan in the system will in some way ease your clearance into controlled airspace, this is only partially true. There is a considerable gap between filing a flight plan, and finally receiving a squawk, frequency and clearance to blast into controlled airspace. Your flightplan will not necessarily be sent to every conceivable class D provider that you might wish to use to organise you clearance, and therefore you will be treated with caution if you call xyz Approach up unannounced looking for asssitance. This is precisely the point that AlphaAlpha makes.

As a result, the normaly way of getting your clearance, having departed from an uncontrolled field, is to call London Information telling them your registration, position, time of departure and requirements, and they will activate your flightplan and liase with an appropriate ATC unit to arrange your clearance. In due course, they will relay a squawk and frequency and hand you to your airways controller (or as appropriate).

2D

Slots are issued 2 hours before EOBT for flights in the system already on a first-come-first-served basis. While there's no doubt that many if not most FPLs can be turned round quite quickly, there's a tactical advantage in getting the FPL in by then if things are going to get busy.

Its a bit of a diversion, but with the exception of low viz or thunderstorm activity within the TMA, it is pretty unusual for things to get sufficiently busy for a serious slot delay to be incurred at typical light GA levels.

I have suffered more slot delays since flying heavier higher stuff than I ever have flying unpressurised piston.

Of course, attempting to fly through the Clacton sector at 1600 on a Friday afternoon is asking for trouble

:O

2D

Further to the discussion on difficulty of obtaining a clearance into the LTMA when departing IFR from an uncontrolled airfield:

Has anybody tried including in the flightplan address list, the unit which will be initially contacted?

For example, in my scenario above, flying from Bourn south into the LTMA via BKY, including Essex radar in the address list. If so, including an estimate for BKY in the RMKs might also help?


Entirely subjectively, I agree with WCollins in that I too feel happier in IMC, compared to low-level VMC, whether in marginal or good visibility. The low traffic density and big-sky theory do provide separation comfort.

Under circumstances where you are flying at WCollins 2250 feet and there may be VFR traffic below a 1500 foot cloudbase, the availability of a radar service does not help much. Under RIS, a fair proportion of the contacts called will not be squawking, or not squawking mode C, hence you have to trust that they are actually VFR and below cloud, so separated from you. At least this is my mind-set inthese circumstances. The benefits of RAS here are questionable -- you would be lucky to make much progress towards your destination.

AA

One thing you can try, and seems to have a reasonable amount of success for me, is to add the address of the unit you wish to call first on the addressee part of your flight plan. In most cases, this is the ICAO id suffixed with 'ZTZX', but either the AIP or a phone call will give the definitive answer. (in fact, if calling the ATSU on the 'phone first, they might well tell you who they would like it addressed to)

Just another drop of oil into the vast number of cogs.....

Hey! Steady on, that's my altitude...you go and find your own :E :p

Will