VFR, VMC, IFR and IMC

[jau]

Hi all,
Could anyone help me sort out the differences between VFR and IFR and who can exersise the right to use them?

The way I understand it, VFR is wereby a pilot can maintain VMC, and cannot be used in IMC.

IFR can be exersised in VMC or IMC, but MUST be used in IMC and class A airspace. IFR can be cancelled and the flight can continue so long as it remains in VMC.

Can a PPL exersise IFR provided he remains VMC (ie, he is not FORCED to use IFR because of the weather or class A)? Or do you have to have an IR to go IFR even if it's in VMC?

Also, when VFR, you cannot fly closer than 1000ft verticaly from cloud, and you must maintain sight with the ground. Does this mean that you cannot fly above cloud? I mean, what happens if you climb to 6000ft in clear skies, but then you come across some scattered clouds lower than you? I can still see the ground though the clound patches, and I am not flying closer than 1000ft to the cloud, do I have to desend to fly under it or can I maintain my flight level?

ONE last question, sorry. My book says that for a radar guided approach, the controller will give out height, and so it is advisable that QFE is set. I've jumpseated a few times on 737's and 747's and I have always thought that the pilot set QNH. Can someone clarify?

maybe I should give it a rest and have some tea!
Thanks

[OneIn60rule]

question.

Yes I believe you can overfly clouds BUT you should always be able to see the ground.

What it means is even though you'll fly over one cloud then you should be able see the ground beneath you in some way. Looking to your far left to see the ground or to your right etc..

*If you fly over clouds and cannot see any ground feature at all then you are illegal since you can no longer tell where you are. *

Flying over scattered fog for example, you fly over a cloud and still you are legal, why? Because you can see the ground through the holes.


The IR bit, I cannot believe that you could possible go IFR if you don't have an IR since the IR is there to enable an IFR.

You can file IFR in any type of weather since you might be wanting to fly very high (12000 feet over clouds etc.). But don't believe me on this one.:ok:

[High Wing Drifter]

A vanilla PPL can fly IFR so long as they are in VMC. For example night VMC flights are IFR. So you don't need an IMC/IR to get a RAS nor to fly at night. Outside of controlled airspace all IFR means is that you comply with rules 29 and 30 (minimum height and quadrantal/semi-circular). Obviously a flight plan and position reporting is needed for flights that transit any controlled airspace under IFR.

Have a gander in the ANO.

[BillieBob]

OK, some assumptions to be made here since not all countries adhere exactly to ICAO. Since you have posted from the UK, we'll assume that you are flying an aeroplane in UK airspace by day and hold a UK (not JAA) PPL.

++++++++++ Question 1 ++++++++++

Visual Meteorological Conditions (VMC)

In Class C, D, E, F or G airspace, above FL100 - a minimum of 8km flight visibility, 1000ft vertical/1500m horizontal separation from cloud
In Class C, D, E, F or G airspace, below FL100 - a minimum of 5km flight visibility, 1000ft vertical/1500m horizontal separation from cloud
In Class C, D or E airspace, below 3000ft AMSL - a minimum of 5km flight visibility, clear of cloud and in sight of the surface
In Class F or G airspace, below 3000ft AMSL and less than 140kt IAS - a minimum of 1500m flight visibility, clear of cloud and in sight of the surface

There are no VMC minima for Class A airspace since VFR flight is not permitted
There is no Class B airspace in the UK

Instrument Meteorological Conditions (IMC)

Any meteorological conditions less than VMC minima

Visual Flight Rules (VFR)

Within Class C, D or E airspace (controlled airspace) - Rules 25 & 27 of the Rules of the Air Regulations 1991:
1. Maintain VMC (see above)
2. File a flight plan
3. Obtain ATC clearance
4. Maintain radio listening watch
5. Obey ATC instructions

Within Class F or G airspace (outside controlled airspace) - Rule 26 of the Rules of the Air Regulations 1991:
1. Maintain VMC (see above)
2. errrr - that's it

Instrument Flight Rules (IFR)

Within Class C, D or E airspace (controlled airspace) - Rules 29, 31 & 32 of the Rules of the Air Regulations 1991:
1. Fly at or above Minimum Safe Altitude
2. File a flight plan
3. Obtain ATC clearance
4. Fly in accordance with the clearance obtained and any notified SID, STAR or holding procedure
5. Inform ATC of any deviation from the clearance obtained
6. Inform ATC on leaving controlled airspace or landing within it
7. Make position reports as notified or required by ATC

Within Class F or G airspace (outside controlled airspace) - Rules 29 & 30 of the Rules of the Air Regulations 1991:
1. Fly at or above Minimum Safe Altitude
2. Obey the Quadrantal or Semicircular Rule as appropriate

++++++++++ Question 2 ++++++++++

The holder of a UK PPL who does not also hold an Instrument Rating or IMC Rating cannot fly in conditions "which require compliance with the Instrument Flight Rules". It is permitted to fly under IFR in other conditions but it is difficult to see any point in doing so by day. (ANO Schedule 8, Section 1, para. (2)(e) & (2)(f))

++++++++++ Question 3 ++++++++++

Two things govern VFR flight above cloud; VMC minima and licence privileges. VMC is achieved 1000ft vertically clear above cloud and licence privileges are maintained if the pilot is "in sight of the surface" (ANO Schedule 8, Section 1, para (2)(c)(iii))

++++++++++ Question 4 ++++++++++

Whilst the AIP does state that, "To ensure the greatest possible degree of safety and uniformity" pilots should use QFE for the approach, most companies use QNH and, in practice, ATC at large airfields will normally assume that to be the standard. Smaller airfields where most pilots are PPL holders continue to use QFE as the norm for approaches and circuits.

Any spare tea in that pot?

[Send Clowns]

The problem with QFE is that it is not use din many countries at all, largely because it is impossible to set a low enough subscale setting for even moderately-high-altitude aerodromes.

[MasterCaution]

I was just looking up the references for this thread in the ANO. Schedule 8 Part A Section 2 on the JAR PPL, refers to JAR FCL 1 para 1.175 which prohibits IFR flight without an IR unless (amongst other things) "national legislation requires flight in accordance with IFR under specified circumstances (e.g. at night), the holder of a pilot licence may fly under IFR, provided that pilot holds a qualification appropriate to the circumstances, airspace and flight conditions in which the flight is conducted".

So the privilege of daytime IFR in VMC in the open-FIR for JAR PPL holders is a side effect of having to use IFR at night? (As opposed to UK PPLs and NPPLs who get it directly.)

MC.

[High Wing Drifter]

MasterCaution,

My interpretation (probably wrong) is that the conditions for the JAR FCL are as laid out in the ANO, i.e. no PPL IFR in A,B or C without an IR and no IFR in D or E without an IR or an IMC. The reference to IMC in itself seems to corroborate my view (well with my twisted logic it does!). By that I mean not just a side effect of the night qual but also the IMC.

[FlyingForFun]

Jau

Assuming you're talking about the UK (you don't actually specify) then everything you say about VFR/IFR/VMC/IMC sounds correct to me, with a couple of exceptions

You say that "IFR... MUST be used in... class A airspace." This is not correct. VFR is not allowed in Class A airspace, but SVFR is - and it's quite normal to use SVFR to transit both the London and the Channel Islands CTRs.

As for VFR above clouds, you certainly can fly above a scattered or broken layer, as long as you are within sight of the surface - but you must remain 1000' vertically (either above or below) the clouds.

Flight out of sight of the surface I'm not certain on, but as far as I know there is nothing within the Visual Flight Rules that prevents this. The thing which prevents it is a restriction on your license if you don't have an IR or IMC Rating. What this means is that an IR or IMC holder can fly, IFR, through an overcast layer and on to the top of it. Then, once on top, he can declare himself to be VFR again, and thus not have to follow the quadrant rules. I doubt that this has any real use, though, and I'm not 100% sure that I've got it right anyway.

Outside the UK, the situation is very different - many countries don't allow IFR flight without an IR, for example.

FFF
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[BillieBob]

You see why I restricted by last post to the holder of a UK (not JAA) PPL!

What JAR-FCL 1.175(a) states is that:

The holder of a pilot licence (A) shall not act in any capacity as a pilot of an aeroplane under Instrument Flight Rules (IFR), except as a pilot undergoing skill testing or dual training, unless the holder has an instrument rating (IR(A)) appropriate to the category of aircraft issued in accordance with JAR–FCL.

This is modified by JAR-FCL 1.175(b) to take account of the fact that, in the UK, one may not fly under VFR at night. The easement from holding an IR, however, relates only to flight at night and the ban on IFR by day in JAR-FCL 1.175(a) is unaffected.

JAR-FCL 1.175(b) goes on to allow for the privileges of the UK IMC rating to be exercised, but only in UK airspace. This ties in with the ANO, Section 2, para. 2(c), which allows the holder of an IMC rating to fly under IFR in Class D or E airspace.

To summarise all of this, the holder of a JAA PPL may not fly IFR in any airspace (JAR-FCL 1.175(a)) except:

1. At night, provided a night qualification is held (JAR-FCL 1.175(b))
2. In any airspace provided an instrument rating is held (JAR-FCL 1.175(a))
3. In UK Class D, E, F or G airspace provided an IMC rating is held (JAR-FCL 1.175(b)) and ANO, Section 2, para. 2(c)

To clarify the bit about flying above cloud, the requirements for a PPL holder without an IR or IMC rating, are:
1. To maintain VMC (Rule 25 or 26 as appropriate)
2. To be in sight of the surface (ANO Schedule 8)

To comply with 1. - If above 300ft AMSL maintain 5km or 8km flight visibility and 1500m horizontal/1000ft vertical separation from cloud. If below 3000ft, maintain the appropriate flight visibility, clear of cloud and in sight of the surface.

It is worth bearing in mind that JARs are Requirements and not Regulations. They are only enforceable in the UK provided that they are allowed for in UK legislation (e.g. the reference in the ANO, Schedule 8 to JAR-FCL 1.175). The legislation concerning aviation in the UK is contained mainly in the The Air Navigation Order 2000, The Rules of the Air Regulations 1996 and, oddly enough, the Railways and Transport Safety Act 2003 and it is here that one should look for the definitive position. Unfortunatel, as with anything put together by the legal profession, much of the content of the ANO is quite unintelligible!

[FlyingForFun]

BillieBob,

My interpretation of JAR FCL 1.175(b) is different to yours. I will quote the relevant part of it, so others can read it and make up their own mind:In JAA Member States where national legislation requires flight in accordance with IFR under specified circumstances (e.g. at night), the holder of a pilot license may fly under IFR, provided that pilot holds a qualification appropriate to the circumstances, airspace and flight conditions in which the flight is conducted.The first part, I think we are agreed on: we are flying in a member state where national legislation requires flight in accordance with IFR under specified circumstances.

Given that we agree on that point, let's consider flight under IFR during the day. This is allowed, according to 1.175(b), "provided the pilot holds a qualification appropriate to the circumstances, airspace and flight conditions in which the flight is conducted" Well, the cirumstances are daytime, and we're assuming that all other rules of the air are being obeyed. The airspace is Class G, so that's ok. The flight conditions are day VMC, so that's ok. Therefore, as far as I can see, IFR in Day VMC with a JAR PPL is allowed.

FFF
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[MasterCaution]

Thanks for the comments folks.

HWD: conditions for the JAR FCL are as laid out in the ANO, i.e. no PPL IFR in A,B or C without an IR

As far as I can see, this condition is given explicitly for the UK PPL and NPPL but not for the JAR PPL.

I agree with FFF's interpretation of JAR FCL 1.175(b). It does not state that if IFR is required under specified circumstances that it is permissible only under those circumstances (although it took me a few reads before I realised that).

Trevor Thom's book suggests that day IFR in VMC by a vanilla JAR PPL is legal.

Don't you just love this multiple regulation/requirement inclusion/exception thing! Circuitous routes through the ANO, JAR FCL and the AIP can be fun can't they? ;)

MC

[High Wing Drifter]

I can't disagree FFF's interpretation - lucidly put always.

MasterCaution,
I don't understand where the explicit distinction between the UK-PPL and JAA comes into it though. Have I missed something else?

Great game ain't it. Some consolation for the lack of flyable wx though :{

[MasterCaution]

High Wing Drifter,

I don't understand where the explicit distinction between the UK-PPL and JAA comes into it though.

The old UK (CAA) PPL and the (UK issued) JAR PPL are different licenses covered by different sections of ANO Schedule 8 Part A. JAR FCL requirements do not apply to the UK PPL as far as I'm aware.

The theme and wording on both S8 sections is generally similar but the particular difference relevent to this discussion is that the no IFR in classes A, B and C restriction is given explicitly for the UK PPL in Section 1, 1 PPL(A) 2(e) whereas Section 2 on the JAR PPL doesn't have this explicitly but uses the JAR FCL 1.175 reference to impose the same restriction.

I wonder if lawyers go flying when the weather is too nice for lawying :)

MC

[BillieBob]

Sorry FFF, I am sure that you are wrong in your interpretation. Notice that your quote is a single sentence, the subject of which is "where national legislation requires flight in accordance with IFR under specified circumstances (e.g. at night)". The easement in this paragraph therefore does not apply in circumstances where national legislation does not require flight in IFR and the prohibition of JAR-FCL 1.175(a) applies.

Therefore flight under IFR by day, in airspace where national legislation does not require flight in accordance with IFR, by the holder of a JAA licence is prohibited by JAR-FCL 1.175(a) unless an IR or IMC rating is held.

[RichardH]

Interesting discussion not helped by the UK and JAA differences which does cause some problems. That said I shall put my commercial instructor hat on and try to help you through the minefield.

You elect to fly under either VFR or IFR rules.

Whether you CAN fly under these rules is determined by the VMC minima (as stated in previous posts) AND what type of airspace you are going to be flying in and your qualifications.

If the actual met. conditions are below the required VMC minima then IMC exists and you MUST fly in accordance with IFR. The whole point being to make sure that you are above MSA at a suitable FL so you don't fly into cumulo-granitas. So as a basic PPL make sure you remain visual otherwise you might not live very long.

That the other end, flying on airways (class A) on a gin clear day, though your conditions are VMC you MUST fly in accordance with IFR. Class A - NO VFR permitted EVER, the SVFR given in some control zones is an ATC concession and must not be assumed as a right. I have known ATC refuse SVFR.

In theory, a basic PPL could file an IFR flight plan (given VMC) in airspace where full IFR requirements aren't needed however there isn't much practical point.

There is no such thing as VFR at night. Your flight conditions might be VMC but the flight must be carried out under IFR, en-route obstacles again. (SVFR to clear a zone).

You USED to be able to fly "VFR on top" ie above layer of cloud, but as stated in ANO 8 a basic PPL must remain in sight of the surface at all times.

Summing up :-
VMC conditions fly either VFR or if required and qualified IFR.
IMC conditions MUST fly IFR - therefore be qualified.

Once you have experienced flying IFR and got a full IR which allows you in the airways system you shall wonder why you ever bothered with VFR. Trouble is it's expensive to get there!

Regarding landing QFE or QNH. The UK are almost alone here and certainly for most commercial operations QFE is NOT used.
All IFR charts have obstacles and procedures assuming that QNH is going to be the prime reference. There is a rule that does require that on departure and upon a missed approach at least one altimeter MUST be set the airfield QNH. Changing from QFE to QNH whilst carrying out a missed approach is something you can well do without.

Jau - though your book says radar controller reads out height, you just inform him (probably knows anyway) that you are landing QNH then he will read out altitude for you.

I learnt using the QFE method but know I am a firm convert to QNH approaches, but you must bear in mind airfield/runway elevation. Not a problem throughtout most of the UK but interesting at Saltzburg at 1600 ft AMSL with the mountains - best go at night if easily scared!.


jau & others hope this was of some use.

[jau]

Ok well thank you for the clarification.
So I can fly above cloud, so long as I can still see the surface. How much surface do I have to see in order to remain VFR? I take that as soon as you loose sight of as much surface that you can longer navigate visually, your are then IFR.

At night PPLs (with night rating) file IFR, even thought they are still VMC.

And pilots in the UK fly QNH approaches anyway.

Right?

once again, I appreciate your help.

[RichardH]

In a nutshell - yes.

VFR above cloud - no fixed figure but I reckon your own answer is what the lawers/CAA require. Take care though as gaps can soon disappear, good airmanship required here.

Night circuits would not normally require a flight plan and if your
night cross country didn't encounter any controlled airspace then an IFR flight plan is not mandatory. However you should request an IFR departure/clearance from ATC.

As I stated before the prime reason for IFR at night is obstacle clearance.

MOST commercial operations and some commercial training schools use QNH approaches.

[FlyingForFun]

I take that as soon as you loose sight of as much surface that you can longer navigate visually, your are then IFRNo. You have to be in sight of the surface, and that's it. If there's a miniscule gap in the clouds and you can see the ground through the gap, then, according to the letter of the law, that's ok.

A subject which comes up frequently is the difference between "safe" and "legal". Flying in these conditions, although legal, is quite clearly not safe if you haven't had training in the appropriate methods of navigation (and we won't even bother to ask how you managed to get there, or how you plan to get back to the ground). We're lucky to enjoy an activity where the law so often leaves it to our own discretion to decide what's safe, rather than legislating it for us.

FFF
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[High Wing Drifter]

We're lucky to enjoy an activity where the law so often leaves it to our own discretion to decide what's safe, rather than legislating it for us.
Amen to that :D