Talk:Special visual flight rules

SVFR merge with VFR

Re proposal to merge with Visual Flight Rules: I vote against. SVFR is a bit of a misnomer - it is definitely not VFR.BaseTurnComplete 10:14, 4 April 2006 (UTC)

Since no-one else has voted I've removed the merge tag. SVFR is not directly related to VFR, despite the name.BaseTurnComplete 21:12, 15 June 2006 (UTC)

I am not in favour of a merge, but of course SVFR is "directly related" to VFR. To say otherwise requires a redefinition of either "directly" or "related". Paul Beardsell 12:46, 16 November 2006 (UTC)

Hmm. VFR requires VMC. SVFR does not, for starters Without delving too deeply into semantics, that's a pretty major distinction and therefore does not require the redefinition of the word "directly" in my opinion.BaseTurnComplete 11:52, 11 January 2007 (UTC)

I agree VFR requires VMC and SVFR does not. (The article as it stands seems to say otherwise, somewhere, but it is wrong.) SVFR requires a different set of meteorological conditions from IMC. Some less but some more. But I cannot work out what point you are making. Obviously SVFR is related to VFR, otherwise it wouldn't be called "Special VFR", it would be called XFR or YFR or ZFR. Paul Beardsell 11:58, 11 January 2007 (UTC)

It's possibly my profession leaking into the writing. ATC treats SVFR very differently to VFR. I think we both agree with the point anyway, that the two articles shouldn't be merged!BaseTurnComplete 12:03, 11 January 2007 (UTC)

"compromise"

SVFR exists as a compromise between two sets of rules? Who says? Reference required. Paul Beardsell 10:04, 11 January 2007 (UTC)

I have culled this text:

They exist as a compromise between visual flight rules (VFR), where other aircraft and terrain must be seen-and-avoided and pilots fly by utilising external visual cues, and instrument flight rules (IFR), where pilots fly by utilising on-board instruments, and use promulgated procedures and Air Traffic Control (ATC) assistance to avoid other aircraft and terrain.

There is no "compromise" and no regulator explains SVFR this way. This might be the writer's understanding and it might be a helpful way of thinking about it (but it also confuses!). Paul Beardsell 10:23, 11 January 2007 (UTC)

It is my interpretation (and the interpretation of other aviation professionals). However as you say it is not an official description, therefore if it confuses others then it goes.BaseTurnComplete 11:10, 11 January 2007 (UTC)

"means of flight" & "for some reason not permitted"

Cut:

SVFR is intended as a means of a flight, that is intended to be flown by external visual cues not by instruments, to be able to enter more restrictive airspace where VFR flight is for some reason not permitted.

(1) A "means of flight" is the flapping of wings, or such like. SVFR is a set of rules.

you've ignored an "a" - a means of a flight, not a means of flight. Include that and the meaning changes to a correct one.BaseTurnComplete 11:14, 11 January 2007 (UTC)

The flapping of the rules will never be the means of even one flight.  :-) Paul Beardsell 11:44, 11 January 2007 (UTC)

(2) SVFR can be requested where VFR is permitted. It isn't usually but, nevertheless, the sentence is wrong.Paul Beardsell 10:36, 11 January 2007 (UTC)

Correct. My mistake. SVFR is such a nebulous concept that, in the verbal gymnastics to try and define in non-jargon words what it is, I appear to be confusing things further.BaseTurnComplete 11:14, 11 January 2007 (UTC)

"separation" & "instrument rating"

Cut:

"Like flight under instrument flight rules (IFR), air traffic control will provide SVFR aircraft with separation from other aircraft; unlike IFR flight, the pilot does not necessarily require an instrument rating (although some countries require it in certain circumstances),"

No! IFR flights are not always separated by ATC. IFR flight is frequently undertaken outside of controlled airspace. So: No separation. Flying under IFR rules only requires an instrument rating in IMC. This is a common misconception. So culled text is wrong, twice, again.

Paul Beardsell 10:46, 11 January 2007 (UTC)

We're talking about SVFR. SVFR is only ever inside controlled airspace. The preceding paragraph makes that clear. Per ICAO, ATC always provide IFR aircraft with separation from other IFR aircraft inside controlled airspace. Also, in many countries, IFR flight requires an instrument rating full stop. The UK (and certain other countries) are more the exception than the rule on not requiring one for IFR flight. Culled text not wrong on either count.BaseTurnComplete 11:23, 11 January 2007 (UTC)

To ensure that the wrong impression is not gained all that need be done is to add the words "in controlled airspace". What must be remembered is that the reader of this may know NOTHING at all about airspace rules. Paul Beardsell 11:30, 11 January 2007 (UTC)

The statement is made in general terms. If it is not correct universally then it is wrong. Paul Beardsell 11:31, 11 January 2007 (UTC)

If you're referring to Instrument Ratings, then I don't agree with this assertion. If we held to this in aviation, particularly in aviation law and rule-making, we'd end up writing nothing because many jurisdictions do things differently. The way to proceed, in my opinion, is to write about either a de facto standard or an actual standard (i.e. ICAO, but see my concerns below with this), and then point out important and significant exceptions.BaseTurnComplete 12:31, 11 January 2007 (UTC)

I agree with you as per the de facto and ICAO. But when, in the same or fewer words, we can be more clear and more accurate we should always be so and not allow the difficulty of sometimes being so to give us an excuse. Here, e.g. in the same paragraph we go to the trouble of saying "not necessarily" on a different issue. So why not say "in general" on the other point? I am getting sidetracked anyway: The para seems to say that an instrument rating is sometimes required for SVFR?????? Why would we say here that SVFR does "not necessarily" require an IR. "Not necessarily" means "usual but not mandatory". This would be very unusual! And so should not be phrased this way. Or said at all, here, at WP. Paul Beardsell 12:42, 11 January 2007 (UTC)

Probably my verbal gymnastics again. Apparently you need an IR in the US to operate under SVFR in certain circumstances. That was inherited from previous versions of the article.BaseTurnComplete 12:47, 11 January 2007 (UTC)

confusion re "zone"

In some places in the article "zone" is used (correctly) to refer to controlled airspace which touches the ground. In other cases "zone" is used either incorrectly or where controlled airspace in general is meant. E.g. The article says SVFR flight occurs "usually only in control zones". This is false. It might be (arguably) true if the word "only" were removed. SVFR occurs only in controlled airspace, but not only in control zones.

Paul Beardsell 11:01, 11 January 2007 (UTC)

Let's clear this up completely. I use the term "control zone" here in its correct sense. The only incorrect word is "usually", per ICAO PANS-ATM Doc 4444 1-11. Sentence to now read "only in control zones".BaseTurnComplete 11:28, 11 January 2007 (UTC)

I can't wade thru all that. Please just say what it is you mean by control zone and provide a reference. Here in NZ (an ICAO country) I think the text books only call controlled airspace a "zone" when it touches the ground. I note that the WP reference you provide agrees with me in this respect, at least. Paul Beardsell 11:40, 11 January 2007 (UTC)

SVFR can be requested in controlled airspace which does not touch the ground. E.g. when one doesn't what to fly below the controlled airspace e.g. to cross a body of water or to avoid mixing it with mountains. Paul Beardsell 11:50, 11 January 2007 (UTC)

You're correct about the definition of a control zone. However ICAO clearly says that SVFR is in control zones only, and the UK (for example) follows ICAO on this. The big pain with ICAO is that, despite being the global standard in aviation, it does not publish its documents on the web as it would rather charge an exorbitant fee for copies. This is a bigger problem here that I've bashed my head against before in writing aviation articles on wikipedia. Either we apply the ICAO standards on wikipedia and suffer the citation problem, or we go with one particular authority's regulations which are citable, but are often quite divergent with ICAO and therefore at odds with much of the rest of the world. BaseTurnComplete 12:01, 11 January 2007 (UTC)

re "SVFR can be requested in controlled airspace which does not touch the ground." Just to be clear, this may be the case in NZ and other countries, but is not allowed according to ICAO or in the UK (my local jurisdiction). I think this is the source of your confusion on the meaning of control zone with regards to this article. BaseTurnComplete 12:10, 11 January 2007 (UTC) Italicised "not" added later as my typo was causing all manner of confusion. BaseTurnComplete 13:20, 11 January 2007 (UTC)

You are allowed to quote the definition from the document here. It would be "fair use". I may be wrong about SVFR being allowed in controlled airspace which does not touch the ground. But are you perhaps thinking only of class A? What about someone crossing the North Sea at altitude in a pressurised twin. Are you saying IFR only? Paul Beardsell 12:18, 11 January 2007 (UTC)

Correct. SVFR is allowed in control zones only in the UK and ICAO

Special VFR flight. A VFR flight cleared by air traffic control to operate within a control zone in meteorological conditions below VMC

— ICAO, Procedures for Air Navigation Services - Air Traffic Management (Doc 4444) 1-11

Also, this strengthens your point about the links between VFR and SVFR. Hoist on my own petard! BaseTurnComplete 12:43, 11 January 2007 (UTC)

Still, "zone" is said in the article when controlled airspace in general is correct. Paul Beardsell 12:18, 11 January 2007 (UTC)

As discussed it depends on whether the article reflects the ICAO standard (which NZ doesn't appear to adhere to), or to a broader description of the world at large, in which case we can't be specific about anything, because of all those countries that do it differently! BaseTurnComplete 12:43, 11 January 2007 (UTC)

At the risk of going over old territory, have re-read our discussion I think we've basically been talking at cross purposes all the way through here with regards to the meaning of a control zone. When I use the term control zone in all of the above, I use it as per the Wikipedia definition in the Control Zone article, which is correct as per ICAO. I thought that this was apparent from my use of the wikilink above, but it seems it was not. On top of that I managed to miss a rather important instance of the word "not" above which has caused no end of confusion!BaseTurnComplete 13:16, 11 January 2007 (UTC)

I should apologise. It seems my stronly worded assertion that SVFR is possible in controlled airspace outside a zone may well be wrong. I assumed that without good reason. Paul Beardsell 13:25, 11 January 2007 (UTC)

problems with the examples

Article says:

Examples of the use of SVFR include:

• Flights wishing to leave an airport in class D airspace, to fly VFR in class G airspace, when the visibility is below the minimum for VFR flight in class D but not below the lower minimum for VFR flight in class G.

Yes, of course. I am being churlish complaining about this but this example adds / explains nothing. The reader does not necessarily know that D is controlled and G is not.

a wikilink to airspace classes could solve that one.BaseTurnComplete 11:43, 11 January 2007 (UTC)

• Flights wishing to overfly an airport within a control zone, when ground fog or mist is obscuring the ground visibility at the airport while visual meteorological conditions exist above.

Well, OK. But the existence of the airport is neither necessary nor relevant. Unless you think you can't have a zone unless there is an airport. Not true!But, once again, this applies to all controlled airspace not just zones. Lastly, in some countries VFR flight "on top" i.e. above cloud is allowed so this is not universally relevant. AND, FURTHERMORE, if VMC exists then SVFR is not necessary, VFR would do (where "VFR on top" is allowed). Not sure anout this and to be checked: VMC does not exist above cloud in countries where "on top VFR" is not allowed.

This example was inherited from before. I'm happy to see it go. See above re SVFR in control zones only.BaseTurnComplete 11:43, 11 January 2007 (UTC)

• Flights wishing to fly visually a control zone at night in countries that do not allow night VFR flight.

Hey? If VFR is not allowed then either IFR or SVFR flight is necessary. So "at night" helps not at all!Paul Beardsell 11:19, 11 January 2007 (UTC)

Probably being confusing here again. I was trying to make an example of countries like the UK where SVFR is used as a get-around at night for aircraft whose pilots don't for some reason want to fly under IFR inside CTRs. Probably could be much better worded no doubt.BaseTurnComplete 11:43, 11 January 2007 (UTC)

I've taken the axe to the examples. See what you think.BaseTurnComplete 16:52, 11 January 2007 (UTC)

SVFR at night in the UK

Article says:

In the United Kingdom, a pilot needs a Night Qualification to fly SVFR at night; see Night flight in the UK.

That seems to imply that in the UK one can fly VFR at night and possibly without qualification. This is unecessarily confusing. Better to say: "In the UK VFR flight is not allowed at night."

Paul Beardsell 11:19, 11 January 2007 (UTC)

I don't see the explicit or implicit suggestion in that sentence that night VFR is allowed in the UK, it quite clearly states SVFR!BaseTurnComplete 11:45, 11 January 2007 (UTC)

In the UK flight at night is not allowed without a night rating or an instrument rating. What is said in the article is that "A requires B" where A = "SVFR flight at night" and B = "a night qualification". For the newbie reader the inference could easily be made that what is meant is "SVFR as opposed to VFR" - which is how much of the rest of the article reads. Paul Beardsell 12:06, 11 January 2007 (UTC)

I've removed that sentence anyway. It didn't really add anything to the article.BaseTurnComplete 13:10, 11 January 2007 (UTC)

SVFR in the UK

In the UK SVFR absolve the pilot from the low flying rule that requires the pilot to stay 1000ft above the highest fixed object within 600m distance. Does this also apply to other countries? —Preceding unsigned comment added by Ralf.Baechle (talk • contribs) 11:08, 31 December 2008 (UTC)

A pilot may receive an ATC clearance to do something which is otherwise forbidden in general, or forbidden for the aircraft type, or forbidden for that pilot with his/her set of qualifications, or forbidden . A clearance is not permission to break other rules. So, AFAIK the answer is no, in all countries. Paul Beardsell (talk) 23:01, 2 January 2010 (UTC)

"SVRF" listed at Redirects for discussion

The redirect SVRF has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2024 August 17 § SVRF until a consensus is reached. 1234qwer1234qwer4 02:56, 17 August 2024 (UTC)