a 320 x-wind landing tecnique

[micheloni]

Hi,
I just viwed the video of the airbus a 320 having a wing strike on the Amburg airport last year.

Daes anybody know if the final report has been released.

For my curiosity which is your prefferred landing tecnique during x-wind?

thanks

[Dan Winterland]

For my curiosity which is your prefferred landing tecnique during x-wind?

The one detailed in FCOM 3. We don't really have a choice!

[Gnadenburg]

Well you do if you look at expanded X-W technique notes from Airbus.

And if you have exposure to high w/v, toward the maximum, wing down in combination with decrab is essential.

Airbus confirms this in their notes.

[DBate]

The thread concerning this accident can be found here (http://www.pprune.org/tech-log/316096-lh-a320-rough-landing-hamburg.html).

The official report has not yet been released.

[kijangnim]

Greetings,
The first and last technic is to respect the X-wind limitation, using decrab :}

[Gnadenburg]

Rubbish.

Decrab at 3o plus knots only and you land with 15 degrees angle off. Risking aircraft damage.

Decrab and wing-down/ side slip is a safe combination. I would suggest that some folks who think they decrab only, in fact, use a decrab/sideslip combo in very high wind conditions.

[kijangnim]

Greetings

Due to Roll laws, you cannot side slip a FBW airbus, any type, that s the way it is, now if you still can manage to side slip it, it is not recommanded due to the stress imposed on the rudder, this is not rubbish this is a fact.
BTW it doesnot harm to be less arrogant and more polite

[Gnadenburg]

http://www.skybrary.aero/bookshelf/books/179.pdf

[PantLoad]

Gentlemen:

Please refer to:

1. Airbus Flight Operations Briefing Notes
A. Landing Techniques
1. Crosswind Landings

2. FCOM Bulletin No. 828-1
June 04
Use of Rudder on Transport Category Aircraft

3. Flight Crew Operating Maunal
3.03.22 P4

4. Flight Crew Training Manual
NO - 160 09 JAN 09
P 2/10
P 3/10



As I've said many times before on many topics/issues, please read the book for yourself. It's not nuclear physics. If what you read contradicts
your company's SOP, you have to respectfully point this out to the appropriate people in your organization. (But, you're still compelled to comply with the SOP.)

All of the above-mentioned references are available on the internet. I think after your readings, you'll find the crosswind procedures (not 'techniques') to be very clear and easy to understand. And, I think you'll find much of what both is taught and practiced is nonsense.



Fly safe,


PantLoad

[Gnadenburg]

I started flying 320's with a launch customer. X-W technique has been a poorly communicated evolution- like many things Airbus.

The FCOM's have been full of holes for years. Slowly, information has been inserted all over the place by Airbus.

I still get guys telling me you never need to drop a wing with Airbus because its fly by wire or the active flight control law in the flare is blah blah.

Anything above 10kts X-W I drop a wing for finesse. Above 30kts X-W its for directional control.

Been doing it for the last 12000 hours.

And funny enough, Airbus, after a few incidents, has got around to scientifically expressing what good pilots have been capable of doing for years ( in the link I pasted ).

[Clandestino]

You can sideslip the A320, just don't hold the stick against the rudder. However, timely and appropriate decrab manuever makes sideslip unnecessary. Decrab and just slightly banking into wind worked as a charm for me.

Final world is not out on bent wingtip fence in Hamburg, rumor has it that it was simultaneous left stick with left rudder - not a good combination with right crosswind.

[John Citizen]

The one detailed in FCOM 3. We don't really have a choice!

OK, FCOM man, now what does the FCOM say for those people who don't have reference to it ? :confused:

Read the question again :

For my curiosity which is your prefferred landing tecnique during x-wind?


He did not ask "where do you look up the preferred technique" ? Not everyone here is an Airbus pilot with access to the FCOM. :{

For those who do not have access to the FCOM, the FCOM says :

Crosswind landings are conventional. The preferred technique is to use the rudder to align the aircraft with the runway heading, during the flare, while using lateral control to maintain the aircraft on the runway centerline (Refer to SOP 3.03.22). The lateral control mode does not change until the wheels are on the ground, so there is no discontinuity in the control laws. The aircraft tends to roll gently in the conventional sense as drift decreases, and the pilot may have to use some normal cross control to maintain roll
attitude. :8


You say We don't really have a choice! :ugh:

I believe we have many choices as if you read carefully, it says "the preferred" technique only. It does not say this is the only technqiue with strongs words such as "must" and "only". :eek:

If you refer to "Airbus Flight Operations Briefing Notes - Landing Techniques - Crosswind Landing", you will actually see that Airbus says that 2 different final approach techniques which may be used :
1- wings level / crabbed approach
2- sideslip approach

Yes, Airbus actually says "2 different techniques" may be used !! :eek:

The answer is not so "black and white" and you say it is and there is more than 1 technique which we can use (as per FCOM, in your own words) :8

Learn your FCOM better before you think you are smart enough to advise others to refer to it. :ouch:

Now to answer the original question :

My preferred technique is to decrab (rudder to straighten the nose) during the flare (after the 20' call) and aileron (sidestick) to keep on centreline !!

[john_tullamarine]

Decrab and just slightly banking into wind worked as a charm for me

I'm just a tad confused .. is not the above a sideslip ?

[Dan Winterland]

JC. Spoken like a true Australian.

Your company's FCOM 3.03.22 may say that. Ours has nothing about landing in a crosswind. Our Flight Crew Training Manual (Airbus Industrie produced) says:

FINAL APPROACH
In crosswind conditions, a crabbed-approach should be flown.

FLARE
The objectives of the lateral and directional control of the aircraft during the flare are:

- To land on the centerline

- And, to minimize the loads on the main landing gear.

During the flare, rudder should be applied as required to align the aircraft with the runway heading. Any tendency to drift downwind should be counteracted by an appropriate lateral (roll) input on the sidestick. In the case of a very strong cross wind, the aircraft may be landed with a residual drift (up to about 5 °) to prevent an excessive bank (up to about 5 °). Consequently, combination of the partial de-crab and wing down techniques may be required.

And FCOM Bulletin 827 (Aircraft Handling In Final Approach) says:

Rudder use should be limited to the "de-crab" maneuver in case of crosswind, while maintaining wings level, with the sidestick in the roll axis.

The Airbus Flight Operations Briefing Notes are not an official document in our company and are not used.

So, with the use of the word "should" I and all my colleagues understand we don't really have a choice. And I'm quite happy that I know what my FCOMs say, thank you.

[Gnadenburg]

Sorry Dan but that Airbus Briefing Note on X-W LDG's is official Airbus literature in your company and is used as a TRG reference. It may even be ( should be ) on the intranet for rank and file.

FCOM's are taken too literally and are vague due Franglais. I feel a number of serious incidents have been as a result.

Applying that vague FCOM X-W LDG technique in the very occasional, high X-W conditions of your region, is a trap.

As I've said. I believe folks decrab and slip in the flare, in very high X-W's, to maintain directional control,without realising it.

[John Citizen]

Dan :

And I'm quite happy that I know what my FCOMs say, thank you.

No, I don't think so.

In your first post you wrote :
The one detailed in FCOM 3.

In your second post you wrote :
Your company's FCOM 3.03.22 may say that. Ours has nothing about landing in a crosswind

First you tell me that we MUST follow the FCOM without choice, then next you tell me that your FCOM has nothing about a crosswind landing in it at all. You seem to contradict yourself here. Now do we follow the FCOM or not ?

How can you follow the FCOM regarding crosswind landings as you say we MUST if there is nothing about crosswind landings in there at all ? :confused:

[Clandestino]

Decrab and just slightly banking into wind worked as a charm for me

I'm just a tad confused .. is not the above a sideslip ?

Sideslip it is but it's not sideslip that caters for all of the crosswind. I would only slightly dip the upwind wing down, max 3° out of 7° allowed per SOP, just as I'd squeeze out the drift with the rudder. Perhaps this technique prevented the upwind wing from lifting and maybe it was no more useful than Dumbo's magic feather. Anyway it gave me controllable, predictable and not too rough touchdowns in crosswind. No instructor or captain complained about it and I had no heart to check out if the wings-level would give the same results.

[finncapt]

Having had to test it in earnest shall we say, I can verify that if you apply a large rudder input to straighten the aircraft, after a crabbed approach in a limiting crosswind, the wings will remain level without aileron input.

It prevented us leaving the tarmac after I gave the sector away to a first officer who I thought (incorrectly as it turned out) could handle a limiting crosswind. At least we were on the upwind side of the runway.

It is not comfortable and was not my preferred landing technique!!!

[Rick777]

It sounds like the real answer to this question is it depends on who you are and who you work for. In 10 years of flying the airplane I just used the decrab method, but I saw FOs use a variety of methods since our FCOM did not specify a required method.

[a320drivr]

jeez. Fcom this Fcom that. Just land it like any other airplane. You foreign guys try to turn it into rocket science.

[John Citizen]

Dan :

Your company's FCOM 3.03.22 may say that. Ours has nothing about landing in a crosswind

Try looking in FCOM 3.04.27 - Supplementary Techniques -Flight Controls - Normal Operations - In flight - Landing Mode

This section makes reference to FCOM 3.03.22 (SOP) but the technique I quoted is actually found here !!

[FlightDetent]

I can verify that if you apply a large rudder input to straighten the aircraft ........ the wings will remain level without aileron input.
Please expand :eek:. Per design one should need not to, but in real life a dip onto the stick is unavoidable. This 25+ years old FBW is not prudent enough. :confused:

FD (the un-real)

[OPEN DES]

jeez. Fcom this Fcom that. Just land it like any other airplane. You foreign guys try to turn it into rocket science.

Maybe you are the foreigner here!? :ugh:

[finncapt]

I meant that the wing doesn't rise as it would in older types I have flown if you just rudder it straight (into wind wing giving more lift than downwind wing due to greater speed).

The fbw keeps the wings level.

However, I tended to put the wing down as I decrabbed since it's very difficult to change the habit of a lifetime.

In strong crosswinds, on takeoff, the thing will sometimes shout "bank angle" just after lift off if you use the wing down technique and are a bit slow to level the wings.

[FlightDetent]

Finn, there is a awful lot of misguided ideas about the Toulouse style FBW. On the other hand, plenty of folk who do not have steady access to any courseware like to read the TechLog contributions to learn about the system, many of them true proffesionals. Stop spoiling the thread for them, please!

1) When you put rudder in to straighten for centerline the upwind wing does come up. Once the rolling motion is sensed the FBW will do its magic and dampen it - with slight delay appropriate to 22 years old technology. If you intend to keep wings level an input on the stick is required together with the boot, a pre-emptive command of which the FBW is truly incapable of.

2) I am led to believe, that for strong crosswinds the manufacturer suggests a combination of drift/slip techniques. If it can be done for strong components, it can be done safely for small components - I am the second in the guilty line. ;)

3) Too much aileron+spoilers must of course be avoided for departure. Yet, there is no audio alert "bank angle" on Airbus, id est you never did hear it, have you? Even if there were (737 has it when over 35 deg b/a), right ... is that the one you heard?

I thank you for the excellent opportunity for me to stroll through FCOM and AFM, just to make sure I do not write crap like you do. If you wanna play pilot, get a facebook account. Truly.

FD (the un-real)

[Nevermind]

Flightdetent

As a TRE/TRI on the said aircraft, I find your technical input pretty good but the message is lost in the delivery. Arrogant postings from a position of perceived superior knowledge is always a feature of this site,and your posting sums that up nicely.

Technically I would simply add that FCOM 3, particularly the bulletin info at the back tell most that is required in the knowledge department. However, there's no substitute for experience and it takes a while from handling conventional aircraft to learning to appreciate the benefits of the FBW system.

[finncapt]

Flight detent

I am somewhat confused by your rant as I was suggesting that the airbus fbw does exactly as you mentioned.

I must confess to not reading the manuals as much as you seem to.

I was trying to imply that the fbw helps in a way that wasn't available in older types.

I have been retired for some time now, and may have forgotten the exact phrase that the 320 uses, but I'm pretty certain it shouted something like that which I said.

I haven't flown the 737.

I thought I was contributing to the forum but your comments suggest that I wasted my 35+ years as a professional licence holder.

I shall sign up to facebook immediately!!!

[Meikleour]

Flightdetent:

I think your attitude towards Finn was completely unwarranted. When I converted onto the Airbus in 1994 the AI instructors demonstrated that if the application of rudder to de-crab was GENTLE ENOUGH then the aircraft will indeed keep the wings level. Perhaps your experience is of the `kick off drift` rather than the `squeeze` school! By the way you can also demonstrate when base flying (circuits) the unreliability of the ND wind readout by gently squeezing on rudder as you fly level and again the aircraft flies wings level without the need for aileron.

So, my advice to you young chap would be accept that there may be experiences around which are outside your own! If your profile is indeed correct then I suspect that you may not have 8,000+ hrs on A320/A330/A340 to relate to.

[Nevermind]

Having joined the party fairly late, I thought I'd have a go at explain how the FBW works in a crosswind. Here goes.....

The airbus is an aeroplane, just like any other. In any other aircraft, as you decrab during the flare, you must apply into wind aileron, which gives a sideslip (!) and the net result, if performed correctly, is that the aircraft aligns with the runway, and is banked slightly into wind so that you do not drift off the centreline.
Sideslip requires a bank angle to maintain the track - hopefully runway centreline!
As the crosswind (and hence crab angle) increases, then the amount of rudder and aileron (and hence bank angle) required increases. Airbus says

"In the case of a very strong crosswind, the aircraft may be landed with a residual drift / crab angle (maximum 5°) to prevent an excessive bank (maximum 5°). Consequently, combination of the partial decrab and wing down techniques may be required. "

So, how does this fit in with the world of FBW?

After 0.5 secs airborne, you go into Normal Law, and stay there until touchdown. In roll, you demand a roll rate. Stick input results in a roll demand, until you get to the bank angle you want, when you reduce stick input to zero. Aircraft stay in bank angle selected.

During landing to remove the drift, we input rudder. To keep the aircraft on the centreline, you need some bank - the sideslip as described above. However, in my airbus experience, if you boot the drift off quickly, the control law is slower to respond and it will not catch the roll quickly enough. If you're more gentle - e.g as a previous post gave the example of sideslipping when downwind on base training, - it will keep the wings as you previously demanded i.e. level.
However, you don't actually want level, as you need some bank angle to keep it on the centreline. So you need to demand a small bank angle - using stick input- then take out the stick input when you get to the angle you need.
That's the tricky part!
For people like myself, , taking the stick input back out goes against all the muscle memory we've acquire on previous types. So you need time to get used to it.

For small crosswinds, we don't really bother too much with extra stick inputs, as the decrab and subsequent bank required is small. However, in large crosswinds, as the drift is taken off with the rudder, bank is required to maintain the centreline. And be aware what airbus say about large crosswinds - they don't want more than 5 deg bank angle, so they're happy if you land with some drift.

In summary, great piece of kit, but we all fight against our experience on previous types when we start to fly it. With crosswind landings, I still find myself putting roll rate demand in, but forget to take it out again!

[Dan Winterland]

From Supplementary techniques - Flight Controls.

"Crosswind landings are conventional.........................The aircarft tends to roill gently in the conventional sense as drift decreases, and the pilot may have to use some normal cross control to maintain roll attitude."



John Citizen. The FCOMs contradict themselves in several areas, but as far as my company is concerned, the imperative "Should'' in our manuals is the over-riding one. It's not "Must" or "Mandatory", but when we are told that we should use the crab technique, we do not really have a choice. If you scrape a pod using a different technique, the excuses will run out very quickly.

FCOMs vary from company to company. Ours don't have the crosswind landing techniques section in 3.02.22. I have a copy of a UK operator's FCOM 3 which does. And our FCOM 3 is currently being re-written to align with our parent company, and that is different again.



The Airbus Briefing Notes also contradict our company policy - which is probably why they aren't officially made available to us. The discalimer at the end says:

"This FOBN is intended to enhance the reader's flight safety awareness but it shall not supersede the applicable regulations and the Airbus or airline's operational documentation; should any deviation appear between this FOBN and the Airbus or airline’s AFM / (M)MEL / FCOM / QRH / FCTM, the latter shall prevail at all times".




As an aside, I recently performed an autoland close to the 20kt crosswind limit. The aircraft stayed on the centreline perfectly using a progressive roll input to counter the drift as the aircraft de-crabbed. It was smoother than a no crosswind autoland, which can be a bit firm with the IAE engine fit.

[finncapt]

FD

Regarding my after lift off message.

It may have solely been a feature of 320-100 series aircraft (the first ten? built) or it may have been modded out by software upgrade at a later date.

It was an annoying distraction when it ocurred.

[FlightDetent]

Finn, I got slashed now over my fingers and quite rightly so. Should you be willing to accept, apart from being days overdue, my apologies are honestly offered. Anyone successfuly retired after a safe lifetime career is naturally my role model. If ever I make it there and still have an idea what is the "facebook" of that time, that would really be icing on top.

Let's see where I came from. Our statements: wing doesn't rise as it would in older types ... The fbw keeps the wings level.If you intend to keep wings level an input on the stick is required ... pre-emptive command of which the FBW is truly incapable of. are not in agreement. As I read some time ago from one of the Airbus-struck contributors here, much better tempered than I, (loose wording) "Perhaps it is time to stop pronouncing how conventionally AB FBW behaves, but start pointing out the differencies as well". From my point of view, the TechLog is exactly the place we could learn about the differencies among a computer locked device, magical chariot, and a fine piece of engineering work. Keeping our inputs technically trimmed seems essential.

Im am sure that you read the books no less eagerly than I do today. Very inappropriate of me to assume your profile was faked, without checking first.

[finncapt]

Apologies accepted.