Un-official Approaches

[pistongone]

For those of us flying in the murk, purely for conversational purposes you understand, i was wondering if you would like to share your local knowledge of your home bases? For starters, i happened to hear in a bar the procedure for the un-official vor approach that whent something like this. Fly 218 inbound to LAM and at 2.2 miles you are a mile and a half from touch down, and you should be at 450'. This will put you on the centre line and now turn a few degrees to the right. Not that i have ever used this info, just thought it would be nice to share it! Watch out for the power lines 2 miles out:eek:

[IO540]

That's probably the unpublished approach into Stapleford :) One can find these at every airfield that has a navaid on or near. Wellesbourne, Goodwood, Welshpool, Coventry, you name it. Based commercial operators can get a private CAA dispensation to use these, and they are often overtly used for instrument training in VMC. They are usually known to the locals.

It would be great to get a collection of them, because somebody woul dhave done the terrain survey and the procedure design at some stage. I have not been flying for long enough but I think many/most used to be published, so somebody should have the old approach plates.

[FlyingForFun]

It would be great to get a collection of them, because somebody would have done the terrain survey and the procedure design at some stageThe problem is, though, that no one is continuing to survey them and ensure that nobody has stuck a tower block or a crane on the approach. Although I might be happy to use an un-published approach at my home airfield if I drove to the airfield and departed that morning and had a good look around whilst doing so, I'm not sure I'd be willing to trust them from a "collection" without knowing how old they were.

At White Waltham, I used to (and I assume pilots still do) track away from the Wallasey NDB on a given easterly QDR (which I forget off the top of my head) whilst descending to your MDA (there was no MDA published, it was left to the pilots' discretion). This would bring you to the southern airfield boundary, so you would look to the left to find the airfield and then join the bad-weather circuit to land. There was a DME check against either Compton or London for a missed approach point, and on reaching that point, if not visual, you would have to make a climbing turn to avoid the LHR control zone.

FFF
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[IO540]

OK, it's quite trivial to design your own VOR/DME approach into some airfield. You have to get the current Ordnance Survey 1:25k maps out, plus the current CAA maps, and work with a generous MDH like say 600ft above the highest obstacle around. If there are any towers etc near the runway then you need to have the MAP further back so you are well visual (or have gone missed) at the relevant time.

A lot of people have done this as a GPS approach, and I am not aware of any evidence suggesting that this is a major source of CFITs, especially compared with how many people get killed flying the official IAPs.

It can be done properly if you have a copy of TERPS, which is online somewhere. To do it really properly needs a survey.

I don't think cranes are an issue since anything tall enough should be notamed, and we are not doing an ILS with a 200ft DH.

To be fair though I have done this only once in the last few years (a combined VOR/DME/GPS approach) and it is the lack of GPS approaches that steals most utility value out of UK GA.

[nouseforaname]

I have made my own GPS approach with step downs and made it up like a Jepp LetDown Chart which I keep in the ship with me. Works really well but my DH is kept quite high as PAX don't like popping out of the murk 200ft above the ground looking down at a green field!!

[englishal]

What about SIDs and STARs :)

[Floppy Link]

...White Waltham, I used to (and I assume pilots still do) track away from the Wallasey NDB on a given easterly QDR...
Wallasey? You sure? Wouldn't that put you in the Liverpool or Manchester zone? :)
Compton? Wescott?
Is there a new NDB down there...I knew I should have bought that new chart!

[eharding]

Woodley.Shirley?

[foxmoth]

my DH is kept quite high as PAX don't like popping out of the murk 200ft above the ground looking down at a green field!!

Also illegal IMHO, if not an official approach I would think you must be looking at a 1000' minimum above obstacles to stay legal - fine using lower until something goes wrong - I am not so worried abot the CAA here, just how quick the insurance will wash their hands of any claim.:ooh:

[FlyingForFun]

Ahem. Yes, I meant Woodley. I've spent too long flying around "oop north".

FFF
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[IO540]

just how quick the insurance will wash their hands of any claim

Insurance does cover negligence. Some things may not seem wise to some but I think they are still worth discussing; how to do them right, etc. The bit about 1000ft applies to enroute IFR; there is an exemption for takeoff and landing (unsuprisingly).

[Colonel Panic]

The bit about 1000ft applies to enroute IFR; there is an exemption for takeoff and landing (unsuprisingly).
So, if you are in IMC, how do you legally get from 1,000' agl to, say, 250' agl, whether you are trying to land or not?

[tmmorris]

Please, let's not do this one again. Use the search facility if you want to see a full discussion; for the moment, please accept that this has been done to death and that 'home-made' approaches are perfectly legal for a private flight into an airfield with no published approach. The CAA did discuss making them illegal a couple of years ago but nothing has yet happened.

Tim

[pumper_bob]

Well i think the original post was for locals to share their knowledge of their fields?
Well for what its worth, if you are flying into top farm you could try the barkway 27 approach. 330 degrees outbound, 9 miles and turn onto 270. You are 2 miles out so down to 600' fotr the turn. Ask Dave to turn the landing light on!!

[Piltdown Man]

Many years ago I was scared fartless by an over-confident IMC instructor (now dead, earth poisoning) who had lots of "un-official" instrument letdowns. He was actually quite good at doing these things but every now and again you'd end up scraping over house roofs, avoiding TV aerials and such-like. These things sound marvellous, until you end up bumping into things which shouldn't be there! And then you have the interesting legal bit: How exactly do you transit from IFR (where you are 1,000' feet above highest obstable within 5 nm of track) to VFR? This seems to imply that you should have a cloudbase of 1,000' AGL to make the transit. So if you have a minima of 1,000' plus airfield elevation, then these things should be OK (assuming similar thought and planing has gone into the go-around, which always appears to be missing from these plans). I could be wrong, but I get the impression that we are talking of using numbers less than this.

PM

[unfazed]

Piltdown Man

I think your understanding is correct, anything less than 1,000 above highest obstacle within 5nm is definitely illegal. Don't think that anybody is promoting descent to lower unless on a published approach.

So yes you do need a decent ceiling for most DIY examples

Also Go around would be to continue on whatever VOR radial that you are tracking and bu£$er off to the published alternate that you have planned and checked the weather for in advance (yes I suppose I am being a tad optimistic).

[IO540]

The last two posts above are a mixture of wishful thinking and being plain wrong.

Everything that is not expressly prohibited is legal.

Whether it's wise is an entirely separate matter.

Unfortunately many people have problems separating the two and that is responsible for a large chunk of bandwidth on pilot forums.

Please, if we have any more posts on this well worn subject, can they be accompanied by references to the primary legislation, the ANO, whose URL is here

http://www.opsi.gov.uk/si/si2005/20051970.htm (HTML version)

[chevvron]

If your airfield has a properly surveyed final approach segment (Type A Survey?), the obstacle clearance within that final approach segment for a non-precision approach would be 250ft above obstacles if you have a final approach fix (FAF) (actually 75m/246ft 'cos ICAO work in metres) or 90m/295ft without FAF PROVIDED your missed approach area was also clear of obstacles.
They're very complicated equations to work out, and should only be done by those with the correct computer software; there is also minimum safe visibility to be taken into account and this also has a factor for any available airfield lighting.
I wouldn't recommend anyone doing the calculations without the necessary experience or without getting it checked by a qualified person; licensed airfields normally get CAA (DAP) to do it but I understand other organisations can now do it with CAA approval.

[bookworm]

there is also minimum safe visibility to be taken into account and this also has a factor for any available airfield lighting.

Visibility/RVR minima are tabulated in the UK AIP for different DH/MDH values and lighting systems. For those of us that use charts from the AIP rather than from third parties, it's a regular part of preparing for an approach. It's not the responsibility of the approach designer.

I would say that approach design is definitely an area of aviation that is "terribly unforgiving of any carelessness, incapacity or neglect"!

[Piltdown Man]

The last two posts above are a mixture of wishful thinking and being plain wrong.

Please, if we have any more posts on this well worn subject, can they be accompanied by references to the primary legislation

IO540 - Which bit of of the ANO, PART 5, Operation of Aircraft, Section 49. "Non-public transport aircraft — aerodrome operating minima" isn't clear? From the way I read it, it appears that you can't decend to less than 1,000' AGL unless you have the prescribed visiblity for a notified approach. However, I suppose knocking up your own letdown allows you to ignore that rule. But there again, being a very ignorant, ill-informed person with maybe I have missed something. So to put me and many others right, how do you legally descend out of the murk with a cloudbase of less than 1,000' on your own letdown procedure?

PM

[unfazed]

IO540 AND PILTDOWN MAN

OK I CAN Admit when I am wrong

Looked more carefully at the ANO and there is a caveat which allows descent below 1000 above hioghest obstacle within 5nm and that caveat is when landing

However I wont be doing that, but it's nice to know that I am legal if I do (in theory anyway).

:)

[drauk]

From the way I read it, it appears that you can't decend to less than 1,000' AGL unless you have the prescribed visiblity for a notified approach.

And if you're not doing an notified approach (i.e. you're doing a home made one)?

[Piltdown Man]

...then I presume that you have to have the prescribed criteria to continue under VFR (less than 3,000' and 140kts, worst case 1,500M vis and clear of cloud). I can't really see the caveat "unless landing" applies here as designing your own instrument let-down is not a standard (legal) method of landing.

[drauk]

I can't really see the caveat "unless landing" applies here as designing your own instrument let-down is not a standard (legal) method of landing.

I think IO540's point is, where does the ANO say that it's not a legal method?

[IO540]

That's right.

To repeat myself: Everything that isn't specifically outlawed (which means reading the law exactly as it is written, without any poetic license) is legal.

This one was done to death a while ago.

[unfazed]

IO540

I't may well have been done to death a while ago but I am pleased that we have given it another "beating"

I agree that if it is not specifically stated then it is not a law

Courts deal with written laws hence ANO unfortunately CAA always appear to me to err on the negative when answering complex questions such as this one. I think it is important when given an answer by somebody in supposed authority to say "OK I take your point ...now can you show me the regulation that states that ?"

Then again I am a bit of an Anti-authoratitive sod but don't forget that if you believe that an authority is wrong or incorrect in what they are saying then it is responsible to challenge (think of co-pilot / captain scenario) ...not always good to defer to authority just for the sake of it.

So...the way I read it if you are landing you can use your own judgement and common sense and if you have a good plan then I can't see what rule you are breaking.....however won't be descending into a mountain valley using ADF DURING A THUNDERSTORM (extreme example I know):rolleyes:

[slim_slag]

CAP393 Endangering safety of an aircraft

73 A person shall not recklessly or negligently act in a manner likely to endanger an aircraft, or any person therein.Would appear to cover all the poor airmanship you get admitted to on here. Probably fair to say the person/people hearing the case will not have a clue about airplanes and will fall over backwards to go with the CAA if they play the safety card (which they will). Of course that will not matter if you have gone and killed yourself.

[IO540]

however won't be descending into a mountain valley using ADF DURING A THUNDERSTORM (extreme example I know

That's sensible, but there are plenty of official NDB approaches that are in that category (high terrain nearby) and nobody is supposed to question that. I think they tend to be designed so that if the DME stepdowns are followed (which they must be) then you won't hit anything, but if the ADF is 30 degrees off then one may not be in a position to make a landing if going visual at the MDH; then one has to make a missed approach, and guess what that will be based on? The same NDB :yuk:

[tmmorris]

IO540,

Exactly! This is why I (and you, no doubt) get so cross about the state of IFR letdowns at smaller airfields in this country. We can't use GPS, yet we're supposed to be SAFER using an NDB.

And no, to add my voice to the never-ending argument, there's nothing reckless about using a home-made IAP designed with a good deal of local knowledge into your home airfield.

Tim

[slim_slag]

And no, to add my voice to the never-ending argument, there's nothing reckless about using a home-made IAP designed with a good deal of local knowledge into your home airfield.
TimWell that wasn't my point, but as you mention it, if you tried that in FAA Land they'd have your ticket before you could shut your engine down. That's the FAA who many on here champion as the sensible regulator with the right approach to safety and risk.

The reason I quoted that reg was to counter those who say if there isn't a reg stopping you doing something then it must be legal. These tend to be people who have made their minds up and are going to do it anyway, and are now looking for justification in the regs. If they cannot find a specific reg allowing them to do something they take another reg and re interpret to say they can do what they were always going to do anyway. I reckon they simply don't know there is a 'reckless' catch all reg in both JAA and FAA land, or they simply say they cannot be reckless, so it doesn't apply to them anyway.

Well, don't tell it to me, tell it to the judge, who I suspect will give the CAA the benefit of any doubt, plus their costs.

[unfazed]

I find the following comments very emotive and reactionary and lacking in any real substance or fact.


A person shall not recklessly or negligently act in a manner likely to endanger an aircraft, or any person therein

So define "reckless" and "negligent" in a planned let down through cloud to a sensible and well thought out minimum ?

Well, don't tell it to me, tell it to the judge, who I suspect will give the CAA the benefit of any doubt, plus their costs

What judge? why would a judge give a monkeys unless you screw up ?


if you tried that in FAA Land they'd have your ticket before you could shut your engine down.

FAA Land has tons of very good approaches into many small strips, they have a wealth of GPS and other cheap ILS type approaches -- Not to mention a fantastic and open to all comers Radar service in most places so turning the question around why would you need to make up your own ? Come on what reg are you quoting ?

[mm_flynn]

if you tried that in FAA Land they'd have your ticket before you could shut your engine down. That's the FAA who many on here champion as the sensible regulator with the right approach to safety and risk.



There is a very fundamental difference in philosophy in FAA land vs. the UK on the effectiveness of big sky vs. see and avoid. The FAA has a view that operating in IMC (no see and avoid) you will hit someone or something unless you are in receipt of a service of some type and on a route segment. The whole idea of IFR flight in Class G as practiced in the UK would be considered careless and reckless in FAA land. The DIY approach is specifically forbiden in the US. But the infrastructure won't support a move to the FAA philosophy in the UK - and to date there is no evidence to support the safety case for such a move.

In the UK, once you have accepted the principle of big sky in Class G there doesn't seem to be that much of an additional risk factor in a well planned DIY approach as compared to scud running.

[IO540]

I am sure it suits the CAA perfectly to keep things just the way they are.

If they brought things into line with the rest of the world (banned IFR without an ATS, etc, etc) then the IMCR becomes close to worthless, because nobody is going to pay for the ATC services, never mind the radar coverage.

The IFR sectors would have to start offering a service to all and sundry... can you imagine the reaction :yuk: ??

UK GA exists on its own; it has to make do as best as it can. Discussing the options is very worthwhile.

[unfazed]

the infrastructure won't support a move to the FAA philosophy in the UK

Agree - Why do we have to put up with no radar cover - understaffed ATC - have to plead for a service and then probably won't get one due to bottom of the priority list and too busy - no cheap practical approach aids

The whole idea of IFR flight in Class G as practiced in the UK would be considered careless and reckless in FAA land That's because it is, must stay below 2,500 in London area but above MSA, no reliable radar coverage available for practical use at those altitudes outside CAS and too busy anyway :bored: