Airblue down near Islamabad

[aterpster]

Iceman 50:

My A330 / A340 flies the airbus procedure very well, but in this case the Cat D circling minimums on the Jeppessen chart of 2510'(842') and 3600m, at Islamabad, would have been replaced by the company minimums of 2656'(1000') and 4600m. The only headdown part of the procedure is the activation of the secondary which has been already loaded and checked.

That's called "1,000 and 3" in this part of the world. A ceiling is required, which the FAA normally does not require for minimums on straight-in IAPs. At a familiar airport and lacking significant precip it does work (barely). At 1,500 and 5 and no precip it works quite well...and so forth.

[BOAC]

My experience with CTL was primarily reading accident reports. I did a few in light aircraft.

- didn't realise that! Then for you the answers to your previous question (you know - driving rain/snow/dark etc) are:

1) You don't attempt it if the weather is too bad or
2) You break it off when the conditions render it unsafe

That is how we are trained.

A PPL told me that

Once again, you miss my point.

- no - your 'point' was incorrect. Why drag your arse in on the wrong runway and drag around a CTL when the magic kit would take you straight in in the first place?

which makes it look like a routine operation

- and so it should be.

[aterpster]

BOAC:

no - your 'point' was incorrect. Why drag your arse in on the wrong runway and drag around a CTL when the magic kit would take you straight in in the first place?

My primary point throughout this thread is the missing straight-in IAP at Islamabad where terrain would not prevent a straight-in to Runway 12. I guess we agree on that primary issue.

[Phantom Driver]

I am reliably informed by an old timer that radar will provide you with a perfectly acceptable vector to 5 nm finals for straight in Rwy 12. Apparently stays well clear of any terrain.

[HundredPercentPlease]

aterpster,

As BOAC points out, a CTL is a routine procedure. That pretty picture I posted which makes it look routine, is in fact what we fly and why it is routine. We do them quite regularly, at airports that preclude a straight in instrument approach due to terrain. Split and Pisa are my regulars, but there are many more.

The Airbus CTL is very straightforward, and very low risk. You have two systems (visual reference and track/time) so if they stop matching up you know something is wrong and you go around. The two of you work together to execute a pre-defined and discussed plan. One mostly eyes out, and the other mostly eyes in. You are both looking for a deviation or a mismatch.

Like all approaches, the risk is increased if you fail to prepare properly. Maybe a CTL is particularly prone to this, because they tend to be done less often and they all seem to vary a little. So gash crews will experience high risk CTLs. Typical mistakes include (but are not limited to):

• Not briefing (an ILS suddenly turning into a CTL due to a wind shift).
• Poor allocation of duties (PNF not briefed what to expect and look out for).
• High cockpit gradient (FO not able to speak up about "unexpected" flight path).
• Hoping you will become visual again shortly.

All of these can be avoided, even if you have to abandon the initial approach and go away and prepare for the CTL.

If an airline has crews that are not good enough to achieve all of this, then it is the crews that need attention, not the whole CTL concept.

[aterpster]

HundredPercentPlease:

If an airline has crews that are not good enough to achieve all of this, then it is the crews that need attention, not the whole CTL concept.

I would rephrase that: training and airport familiarization, not crews "that are good enough."

Also, it is a far different issue in TERPs minimal CTL areas than it is with PANS-OPS.

[GerardC]

to show what the current Airbus SOP is for a circling approach. Approach is flown with A/P at Conf 3 - about 140 or so knots. Maybe less.


My A330 / A340 flies the airbus procedure very well, but in this case the Cat D circling minimums on the Jeppessen chart of 2510'(842') and 3600m, at Islamabad, would have been replaced by the company minimums of 2656'(1000') and 4600m. The only headdown part of the procedure is the activation of the secondary which has been already loaded and checked.

Once again, there is a misconception here (and in the shown Airbus SOP) : be your minimas 842'/3600m or 1000'/4600m, you will NOT have "runway in sight" at the MDA if real visibility is 3600m or 4600m.

CTL is not a visual approach, it is an IFR procedure :
- between MDA and final descent, all you need is to see enough of the ground to be certain to positively identify the approach area ;
- you MUST see the runway to continue below MDA ;
- as stated by 100%pls, it IS a routine procedure IF properly briefed and IF flown according strictly to the SOP .

[BOAC]

You do not need "airport familiarization" to successfully complete a CTL - it is, of course, a bonus. Knowing runway QDM and keeping the 'runway environment in sight' are the 2 prime requirements. It appears AirBlue knew (did) neither.

TERPS is not particularly relevant here - 100%Pl refers to Pans-Ops as does this thread topic. If the FAA wish to pursue a bizarre system for extremely dubious reasons, so be it (I think you would like if differently). Yes, it is not so easy. QED?

- you MUST see the runway to continue below MDA

- actually, Gerard, I thnk you will find this is not so - although once you descend more than xxxft below CTL MDA (insert Terps/Pansops figures as appropriate) you may be 'in uncharted territory'. Where you can CONFIRM your flight path is clear of obstructions you may indeed leave MDA on base - take a CTL in 30k vis? Where it becomes crucial (and should make you seriously consider the wisdom of a CTL) is where the weather is marginal, in case there is an unexpected pile of granite or metal in the way - then the 'local knowledge' certainly helps - take CMF for example. From base to touchdown there is nothing in the way.

[aterpster]

BOAC:

TERPS is not particularly relevant here - 100%Pl refers to Pans-Ops as does this thread topic. If the FAA wish to pursue a bizarre system for extremely dubious reasons, so be it (I think you would like if differently). Yes, it is not so easy. QED?

TERPs CTL criteria have been debated for 15 years. I was part of that debate. New, more PANS-OP-like CTL criteria have been adopted by the FAA and will slowly find their way into TERPs IAPs starting sometime next year. The process will take years to complete.

Having said that I would far rather fly an RNP AR IAP to a runway such as 22L at LIRP than CTL in "adverse" wx conditions. Both Boeing and Airbus have the same viewpoint as I do, as do many others with whom I work.

[BOAC]

Having said that I would far rather fly an RNP AR IAP to a runway such as 22L at LIRP than CTL in "adverse" wx conditions. Both Boeing and Airbus have the same viewpoint as I do, as do many others with whom I work.

- no dispute there - just nice to have a ship that can do that!

[GerardC]

you may indeed leave MDA on base...

Sorry, BOAC, not with my airline SOP's.

"final descent [below MDA] shall only be started with runway threshold in sight and identified".

I readily admit that :
1) SOP vary from airline to airline ;
2) if real visibility is 3600/4600m you will have a hard time to complete your approach.

[BOAC]

Gerard - 4600m (remembering that is 'IFV') should be enough, though?

(I apologise for the 'CTL in 30k' bit which was totally irrelevant to your post - I was on another planet thinking about descending on base)

[aterpster]

no dispute there - just nice to have a ship that can do that!

My hunch is that a significant percentage of the large air carrier birds that fly into Pisa today have the airframe equippage to do RNP AR.

[Nevermind]

GerardC

I wouldn't normallly get involved in these sort of debates but a circle to land is not an IFR procedure beyond when you become visual with the runway.

You'll notice that the diagram says maintain visual contact with the runway. In our company SOPS if you cannot keep runway or approach lights in sight then you discontinue the approach.
The only exception if you have a separate visual approach chart that you can use to be certain of your position.

Humblest apologies if I have the wrong end of the stick here.
But I would not want to be a passenger on a plane that was at at circling MDA, flying downwind and the pilot could not see the runway or approach lights.

[PBL]

Nevermind,

are you perchance confusing Instrument Flight Rules, which may contain details of manoeuvres in strictly continual VMC, with manoeuvres in Instrument Meteorological Conditions?

A (U.S.) contact approach is an IFR procedure which requires continual VMC. You don't cancel IFR when performing a contact approach, and if you are doing it into a non-tower airport you still have to close your IFR flight plan after you land. CTL strikes me as similar.

[BOAC]

My understanding too, PBL, as with a visual approach - still conducted under IFRules unless 'IFR' is cancelled with ATC

[Zeffy]

GerardC

Sorry, BOAC, not with my airline SOP's.

"final descent [below MDA] shall only be started with runway threshold in sight and identified".

And how does that instruct or even imply that the descent from MDA may not commence on a base leg?

[BOAC]

681 posts to wade through, so - has anyone posted a link to the preliminary report? They have made one, haven't they - 30 days and all that - FDR and CVR available................

[mm43]

BOAC;

- has anyone posted a link to the preliminary report? They have made one, haven't they - 30 days and all that - FDR and CVR available......

You'd be joking?! The answer can be found in the Pakistan CAA wikipedia page

[PJ2]

Why, one wonders then, is Pakistan remaining as an accepted member country of ICAO? Blacklisting is effective as it goes directly to the bottom line.