IFR Approach to minimums..are you allowed?

[slackie]

Of interest to all you "bus drivers" flying around (and through) the land of the long white cloud.

Are you aware of the CAA Rule Parts 121.159, 125.159, and 135.159 that read as follows...

121.159 Aerodrome operating minima – IFR flight
(a) A pilot-in-command shall not continue an instrument approach to an aerodrome past the final approach fix or, where a final approach fix is not used, the final approach segment of the instrument approach procedure if, prior to passing the final approach fix or the final approach segment, current meteorological information indicates the visibility at the aerodrome is less than the visibility prescribed under Part 95 for the instrument approach procedure being used.
(b) For the purpose of this rule, the final approach segment begins—
(1) at the final approach fix or facility prescribed in the instrument approach procedure; or
(2) when a final approach fix is not prescribed for a procedure that includes a procedure turn, at the point where the procedure turn is completed and the aeroplane is established on the final approach course within the distance prescribed in the procedure.
[Until Part 95 comes into force, instrument approach procedures are prescribed under Part 19]

[Mud Skipper]

What's your point slackie?

[custardchucker]

yip

what are you getting at

[slackie]

I have it on good authority that CAA are taking an "active interest" in the topic and was just wanting to "raise awareness" for those that might want to "take a look" on those occasions where the advertised conditions might not quite be what is required.

[FL440]

Yip!

I guess the real issue here comes that when the weather is as the rule says "at minimums" one has to make a decision as to whether the conditions are fluctuating? More often than not (unless its fog in HN Slackie then its there a looooong time! :E LOL) when the weather is this poor it does often fluctuate and so where does one draw the line at having a go!?

It would be like departing on a tempo where the tempo is saying conditions will be below minimum, you are still legal to depart because tempo is a fluctuating remark to a point? you would have a go at the apporach in a 'Gap'.

Hey Slackie, whats the onus on you as a controller to advise an aircraft on approach of weather conditions? I presume you would advise an aircraft if it goes below minima so that aircraft can initaite the missed app?

Good to see you ATC's giving us a heads up! :ok:

:ok:

[Chimbu chuckles]

This is just the Kiwi version of UK CAA 'approach bans'. Unless RVR is at or above the appropriate minimum you are banned from preceding below 1000', essentially, on the approach. If you do so they have several 'standard phrases' that indicate you're pissing em off but they won't actually order you to go around...but a world of hurt awaits you when you pull up at the aerobridge.

Difference being, I suspect, that UK ATC have transmissometers that show them what the actual RVR is out on the runway as opposed to having an educated guess and then trying to micromanage your approach and landing. Clearly AKL has transmissometers these days but what of other NZ airports?

[ACMS]

Cathay has had the same "approach ban" rule below 1000' AGL for years and years.

As far as I was aware it was a company thing, maybe it came from the UK CAA and CX followed it?

However it's up to the Crew to use and abuse, not ATC.


And you don't need RVR readings either, VIS will be controlling if RVR is not available.

[mustafagander]

It is very difficult, IMHO, for anybody except the flight crew to know what can be seen at the designated minimum.

[Sqwark2000]

Slackie,

As far as I know it's a reasonably well known rule, particuarly at Eagle where it often comes up in the interview when discussing hypothetical approaches, "...what would you do if ATC advised that vis was below prior to the FAF?" and then " ... but what if you were inside the FAF and ATC advised the same. What would you do?" The rule only applies to visibility, so if you've started an approach and it goes below mins then you could theoretically continue and "have a look".

CAA taking an "active interest"?? Are you refering to a recent incident that was reported by HN Twr involving a regular Air Transport Operator?

S2K

[Capn Bloggs]

The Oz regs seem to be a little more flexible. Perhaps fog at a primary airport would be a no-no but in other cases:

It is very difficult, IMHO, for anybody except the flight crew to know what can be seen at the designated minimum.

and that is why CASA says:

176A Determination of visibility and cloud base for I.F.R. flights
(1) Subject to regulation 257, the pilot in command of an aircraft
operating under the Instrument Flight Rules is responsible for
determining the visibility and cloud base for the take-off and landing
of the aircraft.
(2) In determining visibility, the pilot in command of an aircraft must take
into account the meteorological conditions, sunglare and any other
condition that may limit his or her effective vision through the
windscreen of the cockpit of the aircraft.
(3) In determining the cloud base, the pilot in command of an aircraft
must:
(a) for take-off—take into account the current available weather
forecasts and reports; and
(b) for landing—determine the cloud base from the cockpit of the
aircraft while in flight.

Part of 257 says:

(6) This regulation does not prevent a pilot from:
(a) making an approach for the purpose of landing at an aerodrome;
or
(b) continuing to fly towards an aerodrome of intended landing
specified in the flight plan;
if the pilot believes, on reasonable grounds, that the meteorological
minima determined for that aerodrome will be at, or above, the
meteorological minima determined for the aerodrome at the time of
arrival at that aerodrome.

[slackie]

MODERATORS....Why was this moved??? It directly involves RPT and scheduled Airline pilots NOT GA pilots...CAA Rule Parts 121 and 125 apply to Medium and Large aircraft on Air Transport Operations!!! Please consider moving this back to the other forum!!!!

[slackie]

S2K...nothing was "reported by HN Twr" as you put it...it was as much a surprise for us as anyone else...in fact none of us were aware of the rules as they don't appear in any of our documentation...I had to go looking to find the references.

In HN's case we report the vis as we see it wrt known landmarks and their distances from the tower...we recognise that what we see may be (and in many cases IS) completely different to the vis on the actual runway and as viewed from the cockpit.

We know what the minimums are for the approaches, but do not know what minimums may be imposed by individual companies or in fact what minimums a pilot may impose on him/herself that may be well above the published ones. In fact if memory serves correctly, some companies even have different missed approaches than those published (e.g. I think one company has the MA from NZNR involving a 5 or 10 degree turn that isn't in the published procedure).

[devolved]

At my work, we definitely make this aware to the kiwi students and the UK students (app ban). But I always ask; why have app minima if you’re going to supersede what’s on the plate with this limitation?

I definitely see the logic with a precision approach & this rule, as i could imagine something with a crap load of inertia (74/77) doing at missed at 200AGL would still coming bloody close to the ground.

As for HN, need more rwys? today was "crazy times" :ugh:

[Wizofoz]

Bloggs,

You've hit on a particular bug-bear of mine.

Virtually no where else is it legal to shoot an approach past an approach ban point with conditions reported below minima, as Chimbu has said.

As an FO in Aus, though, I more than once had Captains who would "Take a look" when conditions were obviously below minima. In my opinion this was illegal as there was no "reasonable grounds" to think they would be able to land, but it was never questioned and was a cultural norm throughout Aussie airlines.

I believe Qantas has instigated the equivelent of an approach ban in recent years, and good on them for it.

It is very difficult, IMHO, for anybody except the flight crew to know what can be seen at the designated minimum.

True, but if the vis is below minima before they ebven start, they shouldn't be there!!

If we could now just convince them to always carry an alternate.....

[flyinggit]

Te way I understand it is who makes such decisons & when? the PIC,& nobody could prove otherwise because Wx changes constantly.


FG

[Wizofoz]

who makes such decisions & when?

flyinggit,

It isn't a decision, it's a report. At a controlled airport ATC have visibility reports available from a number of sources, the most sophisticated being a transmissiometer, the least being a groundsman counting runway lights. In any case, what is obtained is a Reported Ceiling and Visibility.

In most countries if this number is less than that required by you (and THAT is a number which might have several variables) you cannot do an approach to minima. In Australia the "Reasonable expectation" loophole is used as an open invitation to have a go.

I believe this will have to be cleaned up before Australia gets Cat II or Cat III approaches, as go-around from those minima are high-risk events which should happen as the rare exception, not the routine event after "Having a look".

[Howard Hughes]

Doesn't Cat IIIC have a 0 feet minima, in which case you wouldn't be having a look, you would be landing...;)
the most sophisticated being a transmissiometer, the least being a groundsman counting runway lights.
The groundsman is probaly more accurate than the transmissiometer, as the beam of light is very narrow and only measures in one direction, also the height at which it measures is considerably lower than the eye height of most heavy jets...:rolleyes:

[Wizofoz]

HH,

Cat IIIB CAN have no decision height (which is actually subtley different from a 0' decision height) but you require 50m Vis to shoot the approach, mostly so you can taxi when you get there!!!

IIIC is, in theory, 0/0, but doesn't actually exisit in practice at the moment.

Actually Cat II and IIIA are where things get tricky, as a go-around from minima (100 and 50' respectivley) may result in a touch-down during the manoeuvre- one reason why the regs should ensure it doesn't happen very often!!

[Capn Bloggs]

Wiz,

First, you may remember Operational Control. Then, ATC had the power to prevent you from commencing an approach if they deemed the weather to be below the minimums. The only power they have now is to close the aerodrome if hazardous conditions exist, and the CAR applies. In conditions and with the facilities )or lack thereof) that we have in Oz, I don't have a problem with the current rules where the PIC decides. As I mentioned in my earlier post, I don't think it'd be very clever to land if ATC was reporting the vis as 200m in fog.

The other issue is that at almost every aerodrome that is not at a capital city, "approach ban" system would be an abject failure because accurate met obs are just never available. The only practical option is to "have a look", which is allowed by the reg. We are all professionals and provided we have options eg an alternate or holding, then why would a crew deliberately press on below the minimums?

[flyinggit]

Thank 'Wiz', how does one 'buy' expeience? Can't wait to get older & be too clever:)

FG

[Wizofoz]

Hi Bloggsy,

I'm actually of the opinion the the evolution of ATC in Australia, particularly our unique Operational control, is where the problem lies. The rest of the world, where the pilot/operator had operational control, had to evolve rules to ensure saftey. This led to the almost universal application of approach bans. In Australia, ATC just wouldn't clear you for the approach, so the decision whether to commence an approach never came up!!

Re remote airports, I'm in total agreeance, but infact it is covered by the philosophy. You cannot continue an approach beyong the ABP if REPORTED conditions are below minima. A forcast is not a report so, in the absence of a qualified Met observer on the ground, there is nothing to stop you doing the approach.

I'm also not talking about people going below minima. I'm saying that routinley going around FROM minima is a bad thing. If you shoot a precision approach, particualrly a Low Vis one (Cat II or better), you should have the expectation that you will land off of it. Go-around from these low minima is always an option, but is a higher risk manoeuvre than normal and should only be done exceptionally. Shooting an approach with a report of conditions below minima means you are PLANNING a go-around from as little as 50', and is not acceptable as a routine event any where else in the world.

After all we usually fly around IMC missing things by 1000', not 50!!

As I mentioned in my earlier post, I don't think it'd be very clever to land if ATC was reporting the vis as 200m in fog.


Exactley, so why even shoot the approach? I have in a 767 (which I wasn't in charge of). Three times to minima then off to Melbourne. Waste of time, money and exposure to unneccessary risk, but I was the only one who thought it was a bad idea!!

[Capn Bloggs]

Wiz,

No argument about go-arounds where you may bounce the wheels off the ground. But that doesn't apply in Australia (yet). All our current G/As, especially if conducted from the DA or the MDA at the Missed Approach Point, are simply not a big deal (or shouldn't be).

[neville_nobody]

the visibility at the aerodrome is less than the visibility prescribed under Part 95 for the instrument approach procedure being used

As mention before the only person to assess the viz at the minima is the pilot and it can change! The location of the measuring equipment can be misleading. I have on two occasions done visual approaches and landed quite safely and legally with the reported viz well below the landing minima. That's because the fog/rain was on one end of the aerodrome and I was landing in bright sunshine at the other. So if you were to introduce such rules how would you determine the viz at aerodromes where RVR is not available?

[Wizofoz]

But that doesn't apply in Australia (yet). All our current G/As, especially if conducted from the DA or the MDA at the Missed Approach Point, are simply not a big deal (or shouldn't be).

Agree to dis-agree Bloggsy, I still consider it iffy to go to a Cat I minima if you are probably not going to land, and actually maintain that the "Reasonable expectation" bit makes it unlawful, and would leave you very exposed legally should anything go wrong (But maybe I'm just a wimp!!).

As I said, it is DEFIANTLY something that would need tightening once we (Finally!!) get Cat II or III in Aus.


quite safely and legally with the reported viz well below the landing minima.


That's the whole point, Nev. It WOULDN'T be legal under the legislation of almost every other country other than Australia because it would have been ILLEGAL to continue the approach past the Approach ban Point with REPORTED vis less than the minima.

So if you were to introduce such rules how would you determine the viz at aerodromes where RVR is not available?

RVR measuring capability is a requirement for low vis ops so, if we do get Cat II or better, an RVR for the particular runway will always be available.

[Howard Hughes]

Three times to minima then off to Melbourne.
While I agree with Bloggsy that it is OK to do the occasional missed approach and really should be no big deal, there is certainly no need to have 3 goes! If you are not getting in off two approaches you're not getting in...:eek:

Three strikes and your out has no place in aviation!

[Cloud Cutter]

Thanks for the heads up slackie. Out of interest there's another part of 125 that says you can't even depart if conditions are forcast to be below landing minima (I've canned the odd flight on this premise). I believe 121 has no such restriction.

I'm interested that you guys aren't made aware of this rule, but I guess it's not of great concern to you.

In terms of landing with conditions below minima, that doesn't really come into it, because vis minima are designed for you to make a normall profile decent and landing from MDA/DA, and if you don't have the required vis to do this, you shouldn't acheive the requirements for decent below MDA/DA - this is the main test for required vis, and relates to the earlier comment about vis from the cockpit being the main thing that matters.

So it comes down to interpretation, but the accepted rule of thumb seems to be, if conditions are fluctuating below minima, it's OK to continue the approach passed the FAF/FAP and then judge whether or not required landing visibility exists from MDA/DA (see rules for decent below MDA/DA).

Obviously, if you require 2000 m to land, and tower is reporting 400 m in fog, you have no claim to be legaly continuing, unless you're inside the FAP/FAF when advised of the reduction in vis, which would make it legal, but still not a good idea.

[Capn Bloggs]

Approach Ban Point - What's the point?

If the weather is reported to be below the Minimum for landing and it is illegal to therefore do the approach, what is the point of going to or having an approach ban point? Surely the approach should not be commenced at all?

As I see it, the argument boils down to the accuracy of the reported weather. At a airport with a tower, balloons, met office, triangulation equipment for cloudbase and RVR devices/transiomotors (?), there would be a reasonable expectation that what is reported is what actually exists. In Oz, that does not apply at many of our aerodromes. Even a qualified observer cannot determine the cloudbase to 100ft or the vis to 200m which may be the difference I see in the cockpit at the MAPt and therefore allow me to land. The current Oz rules are fine for our current application.

As for not letting an aircraft depart if the forecast wx at the destination is below the minimum (assuming of course one is carrying an alternate), that to me does not make sense.

[Cloud Cutter]

I've never heard anything about an 'approach ban point'.

The NZ regs simply state you may not continue passed the Final Approach Fix (or Point on and ILS), unless the reported visibility is above landing minimums. This is usually about a 5 nm final, so it's possible to comence a lengthy aproach while a heavy shower is passing through, and have conditions change by the time you reach the FAF/P. It could be two or three minutes between commencing the approach and reaching the FAF/P so plenty of time for a squally shower to pass, and it does happen.

[Capn Bloggs]

Cloud Cutter,

I don't see the point of all that. If the conditions are changing so markedly, trying to second-guess what it will be like when you get to the FAF seems like a silly idea. Why not just do the approach regardless and when you get to the MAPt do what what you have to do, either land if you have Visual Reference/can land or G/A if you don't/can't?

[Wizofoz]

I've never heard anything about an 'approach ban point'.

The NZ regs simply state you may not continue passed the Final Approach Fix (or Point on and ILS), unless the reported visibility is above landing minimums.

CC,

"Approach Ban Point" is simply JAR speak (and also used by JAR compliant regs, such as the UAE GCAA regs I fly under at EK) for exactly what you have described- a point on the approach you can't go past unless conditions are reported above the minima. It is usually the FAF, OM or 1000' if neither of those exist.

Bloggsy,


You may not agree with the philosophy, but fact is it is regulation in Europe, most of Asia, the ME and under FAA regs for Airline (Part 125????) operations, so what makes an ILS in Australia any different? (I guess the same thing that makes a flight to a single runway airport not need an alternate!!)

[Kaptain_Kaos]

Thanks guys. Some interesting viewpoints. Some not so interesting.

It will be even more interesting what the viewpoints will be once EVS becomes more commonplace on local aircraft.

The notion of "visibility" will have to be re-written again.

[Wizofoz]

Very interesting point, KK.

To the best of my knowledge, EVS is not certified anywhere as an approach aid. It is (so far) a "Situational awarenss" aid and, as such, having it should not make it possible to land in lower vis than not having it.

Given the rather "Fluid" state of Aus regs, it SHOULD mean that you go around if you do not meet the vis requirements as judged by you, without vision enhancement, at the cat 1 min, but I wonder how often that would actually happen with the nice, clear, uncertified FLIR picture in front of you!!

[Capn Bloggs]

Wizo,
it is regulation in Europe, most of Asia, the ME and under FAA regs for Airline (Part 125????) operations, so what makes an ILS in Australia any different?
Probably the desire to let professional pilots get on with the job of landing when they can and going around when they can't. It's not difficult, even off a Cat 1 ILS. And let's not forget the visibility methods: at the ILS ports I go to it's the safety bloke in the truck counting the lights. Hardly enough, when the vis in fluctuating, to stop aircraft having a go. With your whizzbang visibility thingees in Europe, it's probably different but here...

As I said before, Oz had operational control that achieved the same thing, probably before ABPs even existed. Perhaps we've moved on from that concept...

EVS. I'd like to see that! :ok:

[Kaptain_Kaos]

Wizofoz.

I'm not going to tell you.

But....if you had been "visual" (and i dont mean the .8 miles rubbish) on an operating FLIR and HUD from more than 20 miles out and your HUD and EVS provided the appropriate flare cue with autothrottles, what would you do?

Cheers

[always inverted]

The vis that was reported by the tower on the occassion in question was, as told by the tower "about 1500m" which to the crew may have implied "fluctuating" and as stated that is reported from the tower and relative to known landmarks so may be very different at mda on the approach.

This thread does apply to the "incident" at HN and CAA are taking a very close look at ALL operators EVERYWHERE to make sure the "I'll just take a look" is not done unless the conditions are within the confinds of the rules in which we operate. Ie: above minima till you pass faf/fap then you may continue and assess at the mapt if they report the viz to be below minima once you have passed the faf/p.

But yeah we had a heads up e-mail about this the other day.

[boofhead]

You can't regulate safety. Get real.
If you fly to the MDA or DH and you see what you need to see, then you land. If you don't you go around. What could be easier.
And how does anyone make a claim that this is "dangerous"???
I suppose inexperienced, ignorant and propagandized people might think that, since it is what the regulators and training establishments have been telling them and without knowing the real world they would accept it without applying any logic.
Approach bans and the like are a crock. You can't make an approach because some regulator sitting in his little petty office says you can't? So what are you going to do to satisfy his tiny mind? Hold and use up your gas until you have to make the approach anyway as an emergency? Go somewhere else, probably with lesser approach equipment, using your divert fuel, so that now you have to fly the VOR/NDB with just enough fuel left to get on the ground?
Practice go arounds as well as approaches under the hood or in the sim if you don't have the experience needed to do either of these manoeuvres.

[HardCorePawn]

Got the latest Vector (http://www.caa.govt.nz/safety_info/vector.htm) (Jul/Aug) in the post yesterday... the very first article is all about 'Missed Approaches'...

It had this little tidbit...

On an air operation, be aware that an early missed approach may be necessary if the visibility falls below the prescribed minima before you pass the Final Approach Fix (FAF) or Final Approach Segment. In this instance, a missed approach must be initiated at the FAF. You cannot continue to the Decision Altitude (DA) or missed approach point (Civil Aviation Rules 135.159, 125.159, 121.159).

[Cloud Cutter]

boofhead

I think the idea is to minimise time spent at very low altitude in IMC when there is little or no chance of landing. This mainly applies to non-precision approaches I guess. It is also a way of mitigating the natural tendency to 'push on' in the latter stages of the approach when you may have some degree of visibility, but not that which is required for descent below MDA (i.e. you can see the ground around you, but not the runway, or lights).

[boofhead]

Sure, but what has that got to do with approach bans? If the vis or cloud base is marginal, and legal, you can still get caught in weather that does not allow a clear decision and some pilots will push the limits and get into trouble anyway. It is not the approach, or the lack of a ban, that causes this, it is poor decision-making skills of the pilot.
You cannot regulate safety. Only those who are sitting in comfy armchairs believe you can.
Flying an approach that results in a missed approach is not dangerous, it is a normal event and is practiced many times a year by all instrument rated pilots.
Give the pilots the training and the tools and let them do their job.

[Cloud Cutter]

Fair enough, I don't disagree with your sentiment.

Those are still the rules though, and our freindly tower controler was just pointing out that we may wish to follow them more precisely or risk getting pinged by the CAA. This thread has served its purpose.