IMC rating recommended minima?

[Fright Level]

Does one of you kind instructors have the reference for minima to be used if a pilot has an IMC rating? I've found the 1800m (3,000m in CTZ) in the ANO but I can't find the suggested minima or increment for an ILS and other types of approach.

With an IR, one should add 50' to the minima to allow for altimeter errors unless that error is shown as a figure in the POH. Do you add this to the IMC limits as well?

Thanks!

[Ni Thomas]

This has been discussed ad finitum.
AFAIAA, the RECOMMENDED minima are 500ft higher for precision approaches and 600ft higher for non-precision approaches.
Otherwise the minima are as detailed in the published instrument approach chart.

Your own personal minima will be in excess of the published ones.

[Fuji Abound]

The approach minima for an IMC holder are the same as for those with an IR (the higher minima in the ANO are recommended, not legal minima) but an IMC holder must comply with a minimium flight visibility of 1,800m for departures and arrivals whereas this is not so for an IR holder not involved in public transport.

Needless to say the minima you will actually want to apply will depend on your currency.

[Fright Level]

Thanks for that. The numbers you mentioned came up in searches I ran, but I'm really trying to find the legal/CAA reference.

Needless to say the minima you will actually want to apply will depend on your currency.

Your own personal minima will be in excess of the published ones.

I understand this too but it would be nice to know where the base figures are published so that you could at least have an absolute minima to begin with, eg 200' ILS plus 500' plus 50' = 750'/1800m.

I set my own minima based on the type I fly rather than work hard and fast on weather limits alone. Although none public transport IR does not have the same restriction, you'd be on very shaky ground if something happened and the limits were below the public transport figures.

[giloc]

UK AIP Section "AD 1.1.2 - Aerodrome Operating Minima", and within that 3.3 is about "Determination of DH/MDH".

[Fright Level]

Thanks giloc! It was right below the part I'd read a couple of weeks ago about adding the 50' for altimeter error!

"Pilots with a valid Instrument Meteorological Conditions (IMC) Rating are recommended to add 200 ft to the minimum applicable DH/MDH, but with absolute minima of 500 ft for a precision approach and 600 ft for a non-precision approach."

So the minima are not 500/600 higher for an IMC rated pilot, but absolute minimums to consider after adding 200 feet to the DH/MDH.

Although the AIP says these are recommended figures, only a brave pilot would fly to limits below those recommended for his IMC rating.

Thanks again!

[Fuji Abound]

Although the AIP says these are recommended figures, only a brave pilot would fly to limits below those recommended for his IMC rating.

Incorrect - it has nothing to do with being brave, having an IR or IMCR. The license is a bit of paper that says you may have flown to minima once - quite possibly not in IMC mind you.

If you are current fly to minima, if you are not current and you fly below your personal minima then you are just stupid.

[Fright Level]

Fuji, I'm talking specifically about the "recommendation" that IMCR pilots add the increment. Let's say they were extremely current, flew the same approach 3 times that day in marginal conditions already. The Aerad says 200'/550m. Our IMCR pilot must use 1800m as the ANO says:

Instrument meteorological conditions rating (aeroplanes)

(2) The rating does not entitle the holder of the licence to fly:
(a) on a special VFR flight in a control zone in a flight visibility of less than 3 km; or
(b) when the aeroplane is taking off or landing at any place if the flight visibility below cloud is less than 1800 metres.

Pretty well defined?

For cloudbase limits, the rules say "A pilot may not continue an approach below the Category I decision height .. unless at least one of the following visual references for the intended runway is distinctly visible and identifiable ...". Again no argument, they may not continue an approach.

But the AIP "recommends" an IMCR in practice adds 200' to a precision approach with an absolute minima of 500' yet the Instrument Rated pilot can come all the way down to 200' (say).

The license is a bit of paper that says you may have flown to minima once - quite possibly not in IMC mind you.

I don't agree. The piece of paper is part of the licence that gives you privileges to operate in certain conditions.

The "brave" bit I allude to is the IMCR pilot ignoring the AIP recommendation and coming below 500' on an ILS. Although legal, I would think he would be on very dodgy ground for not following AIP recommendations in the same way my car manufacturer "recommends" I change my brake pads at x mm.

I'm not talking about bravado or "personal minima", I was trying to find the written rule. The books provide the guidelines for the current and not so current IMCR pilot in their notes in section 3.3.3.1.

Anyhow, this has been discussed before my time, but good to get the dust out of my books!

[Pace]

The "brave" bit I allude to is the IMCR pilot ignoring the AIP recommendation and coming below 500' on an ILS. Although legal, I would think he would be on very dodgy ground for not following AIP recommendations in the same way my car manufacturer "recommends" I change my brake pads at x mm.

Fright level.

Just to add a point! There is no way of enforcing a cloudbase bust other than the pilot admitting to it.

Weather might be reported as 100 feet overcast but who is to say whether there is a break in the clouds as you come near the runway and you get the lights and numbers at 400 feet.

RVR is different bust that and you will get the book thrown at you.

Sense tells you to only ever fly within your own limits and comfort zone.
I have known of ferry pilots who have flown an Ils to the ground due to unforecast fog because they had no choice and no where else to go but thats another issue.

There maybe IMCR pilots who are current and capable of flying to published minima then there are IMCR pilots who should never use that qualification for any more than getting out of inadvertant entry into IMC.

You could argue the 1800 M rule for all single engine pistons as well as having at least a 500 feet cloudbase. That is purely on the basis of an engine failure and having enough clear air and visibility to manouvre on becoming visual in a forced landing on or off airport.

I also know of a friend who flies singles and wont go unless his whole route gives him 800 feet cloudbase and 1800 M, very sensible!

There are many pilots who think because they are IMCR that they are now instrument pilots and should fly as if they have an IR, The danger is not knowing your capability or the aircrafts capability in serious IMC.


Pace

[Fright Level]

In an SEP, I personally use 1000' cloudbase and 1800m at my departure airfield (again because these are the limits the ANO apply to SE public transport ops). Not sure my met is up to scratch to say with certainty that I can guarantee those sorts of limits all along my route, but I do adopt a "big picture" and generally fly high enough enroute so I can aim for a lower bit of ground where there won't be any cumulo-granite.

[IO540]

Oh no not that one again

The AIP is not the law. The law is the ANO, and above that is the Civil Aviation Act.

An IMCR holder can fly legally down to the minima on the approach plate. But he needs 1800m met reported vis.

As regards personal minima, these depend on currency and aircraft equipment. For example I am reasonably current and regularly fly an ILS by hand down to 200ft, and it isn't hard unless there is a lot of crosswind etc. Not sure I would want to hand fly it down to zero/zero!

But I also have an autopilot with which I have flown an ILS down to nearly surface (well below 100ft) in clear VMC conditions, as a test, and it worked every time so if I was pushed (emergency) that is what I would use. Using the AP down to 200ft is a piece of cake - you just sit there and watch it. It would definitely take me down to zero/zero (say 10m visibility) especially in close to zero wind which is more than likely if there is fog.

There is a world of difference between the usual sort of clapped out wreckage usually found on the GA scene, and something decent and modern in which everything works and is regularly tested for real.

And there is a similar world of difference between a pilot who does a little bit in each of 20 different types, having an IR but rarely going into cloud, and perhaps doesn't understand much of the avionics fitted (a pretty common scenario), and a pilot who flies only the one plane the whole time and knows what all the knobs do and knows the various quirks. Like the old American saying: beware of the man who has only one gun - he probably knows how to use it.

The issue of currency, and esp. currency on the type, is so important that the difference between an IMCR and an IR is insignificant within a few months of the last check flight. Anybody who thinks their IR (alone) gives them some kind of edge is welcome to turn up for an IR checkride in an unfamiliar plane, with a crappy precessing DI, and see how far they get with it!! I have an IR and it was damned hard work too, but relevant to real IFR flight in something half decent? No. It was done in a clapped out PA28-161 in which I would have never flown IFR for real.

[Fuji Abound]

The "brave" bit I allude to is the IMCR pilot ignoring the AIP recommendation and coming below 500' on an ILS. Although legal, I would think he would be on very dodgy ground for not following AIP recommendations in the same way my car manufacturer "recommends" I change my brake pads at x mm.

I dont see any similarity in the analogy what so ever.

The recommendation so far as IMC pilots is concerned probably derives from the assumption that most IMC rated pilots will not be flying to minima "regularly". In fact in would be just as sensible to apply the same recommendation to IR pilots - as there are many who also do not fly to minima "regularly". In my opinion the CAA has no business including a recommendation in the ANO in the first place. Where do you stop? We would recoomend a pilot who has not flown in IMC for more than three months should not do so. The minima is an absolute minima more fool anyone who operates below their personal minima based on their currency - it matters not one bit whether they have an IMC rating or IR. Have you read some of the accident reports involving non current pilots with an IR?

The piece of paper is part of the licence that gives you privileges to operate in certain conditions.

You need to read what I said, not what you think I said.

I'm not talking about bravado or "personal minima",

I think you were the one who mentioned "brave".

There is a deal of difference between brave and stupid. I simply feel you choose the wrong word.

Anyway as IO says it has been done to death this one.

So far as I am concerned if you are CURRENT and have an IMC or IR rating you are entitled to fly to minima if you wish.

[Pace]

So far as I am concerned if you are CURRENT and have an IMC or IR rating you are entitled to fly to minima if you wish.

Fuji

Intersting bit what Minima ? 200 feet and an RVR of 550 metres I would imagine the powers that be would throw the book at an IMCR flying that? not because of the cloudbase but the RVR.

But I also have an autopilot with which I have flown an ILS down to nearly surface (well below 100ft) in clear VMC conditions, as a test, and it worked every time so if I was pushed (emergency) that is what I would use. Using the AP down to 200ft is a piece of cake - you just sit there and watch it. It would definitely take me down to zero/zero (say 10m visibility) especially in close to zero wind which is more than likely if there is fog.

10540 A radar alt is brilliant for giving you a flare point set it at 10-15 feet.
After a bad experience I wanted to see whether the a Seneca could land in thick dense fog and you were forced to or run out of fuel.
Set the aircraft up in VMC on an ILS with a safety pilot looking out and using the radalt yes you can

Pace

[Fuji Abound]

Pace

I agree. I was referring to the approach minima not the RVR. I appreciate that that for practical purposes when flying to minima the RVR might well be outside the legal RVR for an IMC rated pilot.

There was an interesting article in Flying recently. The pilot froze up - or should I say the aircraft did! The screen was completely covered in ice. He didnt have a radar alt - just standard kit, but managed to land the aircraft from an ILS without damage - as he landed the jolt dislodged some of the ice. A lucky fella, but demonstrates what is possible when needs must.

[Pace]

I agree. I was referring to the approach minima not the RVR. I appreciate that that for practical purposes when flying to minima the RVR might well be outside the legal RVR for an IMC rated pilot.

Fuji

I would imagine there is no legal stipulation on cloudbase because it could never be determined in a way that would stand scrutiny in a court of law. RVR
Can be measured and proved in a court of Law if you break those minima

The chances of having a 1800 metre vis under such a low cloudbase at 200 feet is unlikely in my experience or rather unusual.

Thus if the cloudbase doesnt get the IMCR going to minima the RVR will

Pace

[IO540]

The chances of having a 1800 metre vis under such a low cloudbase at 200 feet is unlikely in my experience or rather unusual.

I would disagree with that. Only once ever have I seen a vis below say 2000m combined with a cloudbase below say 500ft.

But you are an airline pilot so you probably see a lot more in the way of weather, since almost nothing (short of total fog) stops CAT going to a destination. Whereas I would probably cancel the flight in many such conditions, due to other factors (low cloudbase -> a warm front -> high tops -> icing conditions in the terminal area).

[Pace]

But you are an airline pilot so you probably see a lot more in the way of weather, since almost nothing (short of total fog) stops CAT going to a destination. Whereas I would probably cancel the flight in many such conditions, due to other factors (low cloudbase -> a warm front -> high tops -> icing conditions in the terminal area).

10540

I have an ATP But am not an airline pilot merely biz jets secondly I enjoy your posts and the high level of your knowledge.

As to good vis under low cloud bases I cannot remember many times when the cloudbase is given as 200 feet that the vis isnt also down. Maybe through preciptation in rain or drizzle.

Pace

[Fuji Abound]

Can be measured and proved in a court of Law if you break those minima

Hmmm, but in reality if you pitch up and find the RVR is below minima you divert assuming your diversion is better, and if it is not, you declare a pan and land. In either case you have not broken the law unless you departed knowing the RVR was going to be below 1,800m.

Of course that is why in my earlier post I was careful to add the words "might well".

All that said I cant imagine too many pilots with an IMC shooting the ILS to minima, but I also agree with IO540 with modern kit (ASSUMING everthing is working and you fly it on automatics, which is a dangerous assumption) it is not that difficult. However the countless accidents that occur doing just this also proves that it is unsurprisingly unforgiving.

[Pace]

Hmmm, but in reality if you pitch up and find the RVR is below minima you divert assuming your diversion is better, and if it is not, you declare a pan and land. In either case you have not broken the law unless you departed knowing the RVR was going to be below 1,800m.

Fuji

I do not know what the regulations are concerning an approach with less than 1800 metres and a IMCR?

I do know that with the published RVR minima that you cannot even start the approach if below the RVR Minima.
Regarding having to land in that situation it would have to be classed as an emergency to avoid prosecution.

I know of a pilot who was fined £2000 for landing on a portion of runway which was sticking out of the fog in clear air. He landed on that porion including the numbers and then ran into fog 100 metres further along the runway.

As the RVR was given below minima for both ends he was found guilty and fined.

The takeoff minima was 200 metres so I was surprised he could not argue that he had landed in above RVR minima and was effectively landed by the time he hit the fog thus proceding on taxi and takeoff minimas but they still found him guilty and fined him.

Pace

[bookworm]

As to good vis under low cloud bases I cannot remember many times when the cloudbase is given as 200 feet that the vis isnt also down. Maybe through preciptation in rain or drizzle.

Examples from the last 3 hours:

EVRA 170450Z 13003KT 090V150 6000 OVC001 08/07 Q0995 18190060 NOSIG=
EFVA 170420Z 26002KT 4000 -RA BR OVC002 07/07 Q0986=
LFBT 170500Z AUTO 00000KT 6000NDV BKN002 BKN006 BKN012 13/13 Q1019=
KBKW 170451Z AUTO 34006KT 4SM -RA BR OVC002 12/12 A3014=
EYVI 170620Z 24005KT 2600 RA BR BKN002 OVC012 08/08 Q0994 TEMPO 1500 RA BR=

To complete the statistical picture, of the METARs with celing less than 300 ft, approx 15% have vis > 2000 m.