Use of Autoland in Adverse Weather
 

Dear Experienced Pilots

I have a query. If on an ILS, landing in Cat 1 conditions with heavy rain with Cat 2 Dual on FMA, if visibility, despite using wipers/rain repellent, drops suddenly at MDA for a very short period (just for a few critical seconds) without losing the lights but they become fuzzy and may not guarantee a good flare and touchdown, would you continue the approach without disconnecting the autopilot and carry out an autoland, go around, or disconnect autopilot and do a manual landing? I take into consideration a busy airport wherein if I was to do a GA, it would involve a large fuel loss. Of course safety is the primary issue as always. Thank you ladies and gentlemen for your response.

in my company if you want to do an autoland you have to engage the second autopilot way before the mda
so in your case it will be a go around

You don't say whether the required visual references are lost during the brief deterioration of the weather conditions.

Descend below MDA without required visual reference = Cowboy, irrespective of wether the autopilot is engaged or not.

sorry guys / gals, just updated the query based on initial responses.

Mate, if you haven't planned and briefed an auto land, don't do an auto land. Stick to what you have briefed you will do . If you have to go around then good stuff, you've gained the experience of one more G/A and and in doing so you've maintained a safe environment for all those people sitting behind you.
Changing your plan at the last second is a bad idea.

Many companies in EU-land preach the use of dual autopilots on all ILS approaches, so yes, you could find yourself technically able to autoland from DA/H. However, this except in an extreme emergency, is not allowed and worries about 'a large fuel loss' do not normally constitute an emergency. Loss of visual reference at DA/H requires a G/A and I am surprised from your 'profile' that you need to ask!

Your description 'without losing the lights' does not actually constitute loss of visual reference in EUOPS and a 'drop' in visibility past the relevant point does not count - it is the crew's decision whether to continue.

I note you do not tell us which regulatory framework you are licensed under, so it may, of course, be 'acceptable' in yours.

Totally concur with Framer on this.

Go around. If you attempt to fly below your briefed da you're asking for trouble. If at planned da you lose the required visual references, or if in your judgement you can't see well enough to continue safely you must go around. In the time it takes to go from 200 ft agl (cat 1) to 100 ft agl (cat 2) you don't have time to consider variables such as

1) are LVP's in force
2) aircraft auto land serviceability
3) airfield auto land capability
4) auto land crosswind limits
5) decide on and re bug a new minima

There are other things to consider, that list is just a snapshot. Far safer to go around, re brief, and try again. No one has ever collided with the sky.

Agada, it's back to school for you...MDA on an ILS?!?!?!

Autoland systems are basically designed to be used during low visibility caused by phenomena like fog, NOT for tropical downpours with or without windy conditions. Foggy conditions hardly ever go together with extreme wind conditions. (excluding Scotland... :p )
Autopilots most likely have insufficient authority to cope with a large and sudden wind shear or down draft because of entering a shower on short final or flare heights.

Loosing visual reference AFTER You made the decision to land is a nasty one. I one time asked our training manager to incorporate that item in a new Type recurrent. He did and it made for some interesting experiences with several crews as I heard later.

If LVP's are not inforce at the airfield the ILS is not protected for autolands.

Use of Autoland in Adverse Weather
 

@ BOAC: Technically he would not need more than one autopilot engaged to perform an autoland if he was sitting in a 737.

- open to debate. I believe the question has never been answered by Boeing and I did not wish to be the first to find out:).

"Autoland systems are basically designed to be used during low visibility caused by phenomena like fog, NOT for tropical downpours with or without windy conditions"

I can remember an autoland approach to LHR when it was heaving it down with quite a strong, gusting wind as well

Went off quite well - better than hand flying for sure

Better than your handflying, perhaps :rolleyes: ;)

indeed, indeed......... :hmm::hmm::hmm:

On the bus we fly all our ILS's with both auto pilots in so Cat 3 Dual is always annunciated irrespective of whether it is a Cat 1 or Cat 2/3 auto land (Cat 2 is always auto land for us). Clearly on a Cat 1 approach we would disconnect and land manually.

If you have planned a Cat 1 approach then that is what you fly. If you achieve the required references by DA then you can continue to land. If you do not achieve those references, or lose them below DA then you go around. It is that simple.

To do otherwise would be fool hardy in the extreme as the airfield will not be safeguarded, you will be busting your briefed minima and will not have pre briefed what you are up to.

Now if you are in some kind of dire emergency then that would be different but it would need to be dire.

The B777 can autoland with a 40kt crosswind. In BA it was allowable to do that in Cat I conditions or better. It can also autoland one engine out.

Surely you would have anticipated such conditions and set-up for an autoland?

Personally I brief autoland if any significant cloud below 500ft or vis less than 1500m and consider reverting to Cat I if appropriate. Can't go the other way though, and its a bit embarrassing to explain to the CP why you had to go around in a CatIII equipped aeroplane just because you hadn't set it up...

Boeing 737 & 1 autopilot. "technically"... Hmmm, well, yes, it will autoland fine with just one but there's no redundancy so not exactly a sensible thing to do unless you're going to die otherwise. You "could technically" do all sorts of things in any aeroplane but that's a pretty pointless line of discussion really.

It is not protected for Cat2/3 approaches, autoland is at your discretion, not recommended at Munich!

Agree 100%, always brief and fly the worst case scenario then situations such as the OP describes can be avoided safely.

one of the key things about flying is to be ahead of the game...think ahead and accomplish things which will make your flight safer and avoid problems.

it sounds like you aren't thinking ahead...until you posted your question.

IF your plane, the airfield and crew are all certified for CAt 2 or 3 autoland and the wx is right at Cat ONE mins...you have a choice...and you should make it about 15 minutes before you are at the outer marker.

IF the airfield' s wx is above cat one mins and suddenly goes to mins or below, you can't suddenly go back in time and brief your approach.

you should be sharp enough to hand fly the plane and do a great ILS approach. In the simulator, we trained hand flying to 100'DH instead of 200'. We NEVER actually flew in real conditions to 100' dh hand flying...that's breaking the rules.

So, if things get tough at DH you should know what you are going to do by shear pilot instinct (learned after many years).

The magic of the simulator does not really do justice to the critical moment of TRANSITIONING TO VISUAL at DH. I wrote an article about it and its somewhere on the forum here...maybe in the private pilot area. I put it there to help out private pilots.

That splash of rain, and the inability of the windshield wipers to handle it can be a handful. But a pilot knows that can happen.

I think boeing wipers are above average. I think douglas wipers were better. If you have your wipers on at one speed, brief to the non flying pilot to be ready to switch to high speed upon your command or when he thinks its needed.

How many people brief wiper speed and commands during a flight?

YOu can also brief the use of landing lights...sometimes its better to keep them off at night if the conditions are right at minimums.

Also ask ATC to set the runway lights to YOUR preference. Sometimes using different runway light settings can optimize your chances to get in.

Its alot to know...but either play for keeps or get out of the cockpit.

''Technically he would not need more than one autopilot engaged to perform an autoland if he was sitting in a 737.''

Nor in the FBW Airbus types. With one AP, CAT3 SINGLE would be annunciated and it would be a fail operational approach.

Fail passive approach surely?

Modern A/L works well and not only in fog
 

The choice about whether to use an autoland system in adverse weather, particularly related to winds, and shear, depends on the aircraft type, installed AFDS, the mode to be used (e.g., LAND 2 versus LAND 3, Dual or Triple Channel, etc) and the relevant AFM provisions.

It is absolutely not true that autoland is intended "only for use in fog conditions".

APs ranging back to the PB100 or FCS-110, and even before as with the SP50 (e.g., Mod Block IV) had reasonably good capability in winds and turbulence. Whereas modern autopilots have terrific robust capability (e.g., B777, B737NG, B757/767, B744 and B748) in winds, shears, and turbulence. I've done successful and reliable A/L flight testing (and also many authority certifications), as well as operational use, with good resulting A/L performance in modern transport jets, in winds, shears, and turbulence conditions that otherwise would water the eyes of a pilot even attempting to land manually in those conditions, even if in CAVOK. The rule of thumb is fly within bounds of the approved AFM, and within any applicable operator specified policy constraints, ...and A/L will provide safe and reliable service, particularly in modern civil transport jets.

The Boeing autopilot gives an immaculate demonstration of how best to land an aeroplane in strong Xwinds

Not on the 737 it doesn't! Check limitations.

Thank you Tom. Airbus does talk about Autolanding in cross winds as a part of limitations, but no where RECOMMENDS autoland in heavy rain (other than a presentation). Many times pilots just keep going around (and around) because the rain at some point becomes heavy enough to suddenly reduce the clarity of runway lighting (rain is not like a bathroom shower that remains steady) for a GOOD landing, though the reported visibility or RVR maybe even Cat 1 conditions. Autolanding in Cat 1 is permitted everywhere (I hope so) provided the pilot is aware that the ILS beams are not protected as for a Cat II or Cat III approach. My intention of starting the thread was that pilots may become aware that Autoland is NOT limited to FOG related weather only and can be used in case of visibility dropping because of rain - of course when you have briefed for it. A lot of pilots do think that auto land is only permitted in fog related weather deterioration. In Airbus, FMA reads Cat III Dual (Fail Operational) when both AP are engaged and Cat III Single (Fail Passive) with a single AP (for others on the forum). Thank you everyone for your excellent participation and making me wiser and a more aware pilot.:)

The 737 has only a 25kts crosswind limit for autoland, so yup, it doesn't demonstrate the maximum of the envelope of 40kts.

agada, what you describe is mostly a description of exceedingly bad training. Guess your airlines training department need to attend a few retraining courses.

It isn't appropriate to generalize that way, ....about any modern jet's potential capability... You have to address the specific model, and the applicable AFM, and airline policy.

For example, have you had any experience with the EDFCS AP with LAND 3 on the NG???, particularly with GLS?????

I have. It is terrific, ....even on a 90 ft wide runway, in pouring rain, in a very strong gusting crosswind.

''Originally Posted by Dan Winterland

Nor in the FBW Airbus types. With one AP, CAT3 SINGLE would be annunciated and it would be a fail operational approach.

Fail passive approach surely?''

Doh!

This comment reflects another case where you need to read the specific AFM and airline policy, to be sure that one understands the true restrictions and constraints which apply. For some (many?) authorities globally, the AFM 25 knot crosswind provision has the caveat added... "WHEN LANDING WEATHER MINIMA ARE PREDICATED ON THE A/L SYSTEMS USE". This means that for those aircraft with this particular (e.g., FAA) AFM wording, and airline policy sanction, that even when in rainy and very windy conditions, albeit with visual reference, the AL system can still be safely and beneficially used to higher wind values. I and many others have used this provision safely and beneficially many times. Various airlines globally do so too, to great advantage, for both safety reasons, and for their flight crews benefit for workload relief. It is particularly useful when a pilot is tired, and would rather monitor the big picture, rather than have to "hand fly", especially after flying those "all nighters and red-eyes" eastbound, and then face a "bad weather" landing. Modern jet transport APs are vastly more capable than then their predecessors, even more than indicated by the very conservative constraints placed on them by some authorities for taking "credit" for "approval of Cat III minima". As but one example, with aircraft with the appropriate AFM wording, I've safely, legally, and beneficially used many of the new APs in gusting crosswind components well in excess of 30 kts, and they perform most admirably.

If one is so tired that he cannot do a manual landing he should make sure that the CAT III sensitive areas are protected, otherwise the outcome could be something along the lines of the singapore airlines incident in MUC with their 773. in rather benign conditions, 7 to 8 kts roughly along the runway.

Over here we may not use the autoland system beyond its limits except in an emergency, and the wind limits do include all gusts. However, the 737 is a very easy plane to land manually in 40 kts crosswinds anyway, so there is no need for autoland.

Sadly GLS isn't yet certified for lower than CAT I operations, but we did quite a few CAT IIIb trials at EDVE and it works like a charm, actually better than the ILS and without the need for protected areas. But the number of installations is still very low and many airports do not see why they should invest in it if they still have to maintain their ILS anyway for those old fashioned aircraft without GLS capability.

There is of course a difference between the visual references required to continue an approach beyond DA/DH ( which,without getting too specific ,is just about anything that confirms that the aircraft is on the correct trajectory towards the landing zone as opposed to the perimeter road.You don' t necessarily need to see the runway) and the visual references required or desirable to conduct a manual landing.
A cat 1 approach to minimums in 550 metres vis could have you legally continue towards the runway with only approach lights or other approved references visible. Given that the usual visual reference for a good manual landing is the far end of the runway,which in 550 metres vis is way out of sight,most pilots are now entering the twighlight zone of there handling experience.
My mob forbids autoland out with protected LVP conditions but the airplane makes a lovely job of flying to the touchdown zone and entering the flare at the correct rate. Keep your thumb on the disconnect and either chuck it away or correct if something strange happens. Disconnect in the flare , keep it straight and proceed to the bar for a cold one- job done!

Thought rain repellent was banned??