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Idunno
17th Feb 2004, 12:22
There is a thread running elsewhere regarding the AA A300 accident in New York. It mentions the training techniques used by AA regarding rudder use, and suggests they were faulty and contradicted Airbus recommendations.

I'm being taught a crosswind take-off technique that directly contradicts the A320 FCOMs, the A320 OEB relating to rudder use, and the companies own Ops manual! All the above state EXPLICITLY (and in the case of the OEB in underlined text) that the use of into wind aileron is not normally recommended on t/o, but when x/wind is strong it may be used up to VR, however the a/c must get airborne with zero roll rate demand (neutral stick input).

I'm being taught to hold the aileron (roll demand/stick input) into the rotate/initial climb.

Anyone got an opinion on this. It seems unfair to me that I'm being taught one thing while all the books (both maufacturer and operator) say the opposite!

Field In Sight
17th Feb 2004, 17:02
Have a look here:

See How It Flies (http://www.av8n.com/how/htm/takeoff.html#sec-crosswind-takeoff)

The technique seems closer to the 737 style example given.

As in most things flying related, it's horses for courses and one technique might not fit all.

I would do what the Operator/Manufacturer describes.

FIS.

BTW Wasn't the A300 rudder "mis-use" problem related to a wake turbulence encounter and subsequent recovery. Not crosswind take-offs.

BRAKES HOT
17th Feb 2004, 17:21
using lateral sidestick inputs during a x-wind t/o is not a great idea. My company sticks with the Airbus FCOM and teaches against using it during rotation. Once you reach round about 1/3-1/2 side stick the spoilers will start to crack open which in turn creates an additional pitch up moment on rotation - increasing the risk of a tailstrike. The other important issue is that you are demanding a roll rate from the aircraft, not just a certain amount of aileron/spoiler deflection so the aircraft will keep rolling on rotation unless a correction is made.

{Edited for Spellin}

Idunno
17th Feb 2004, 21:07
Field In Sight, Yes I know the AA accident was not crosswind related. I mentioned it because it was a well known accident created by 'innappropriate' flight control operation contrary to the manufacturers guidelines (I'm trying to be as non controversial as possible here). Meantime my own instructors are teaching a flight controls technique "contrary to the manufacturers guidelines", and indeed their own book.

BRAKES HOT, they actually had me practice displacing the stick until I could see spoiler deployment, then backing off a fraction to stow them and referencing that position as a 'learned' displacement for x-wind t/o. Pretty hard trick to control stick displacement that finely on a bumpy/gusty x-wind t/o.
Try it yourself.

They maintain the roll rate demand should be held into the rotation (contrary to Airbus) because if you zero the stick the upwind wing will lift as you rotate. This may well be true, but if the wind suddenly drops off (i.e. after a gust) you may equally get airborne with the upwind wing dropping and that roll being added to by your own upwind roll demand...pod scrape!

m&v
18th Feb 2004, 04:09
flew the a320 for 10 years(from pub to pub) I didn't hold any upwind aileron input ,But I did,in strong crosswinds, hold nose wheel down elevator beyond 100knts to stop any skip until Vr...Cheers:D

Dream Land
18th Feb 2004, 06:59
My 2 cents,

Don't have the experience of m&v but my company uses the same technique, works good, also for landing my company recommends the crab into the wind method until just before touchdown, then aligning with runway, no wing dipping like the C172.

D L:D

Ready
18th Feb 2004, 16:59
My 2 cents as well,

Displacing the stick until spoiler deployment, then backing off a bit to stow them, I agree on that one. Proper technique for any airplane with roll spoilers. I've been doing and teaching it for quite some time and most pilots seem to like the idea. Aileron input is brought to zero just prior to rotation, or into the rotation, to make sure it's totally removed when the airplane gets airborne.

The whole idea is to have min drag at lift off, ie spoilers fully stowed and ailerons neutral. Not to be neglected with an engine out, specially when using V2 min (1.2 of stalling speed) instead of V2 optimum. Don't need any unwanted drag at that point, that's for sure.

But on the other hand, an airplane like the B-757 with no roll spoilers, the technique is quite different. More wind, more ailerons into the wind until it feels appropriate. As well, in this case the aileron input will normally be kept into the wind a bit longer during rotation.

Roll spoilers or not, the airplane should get airborne wings level as much as possible and letting the rudder go to neutral during rotation will provide the proper crab to keep centerline. Don't fight it at that point, everything neutral more or less, should do it.

Cheers!!!

mono
18th Feb 2004, 17:46
But on the other hand, an airplane like the B-757 with no roll spoilers, the technique is quite different. More wind, more ailerons into the wind until it feels appropriate. As well, in this case the aileron input will normally be kept into the wind a bit longer during rotation.

Strange, I always thought those panels on the wing WERE roll spoilers. They certainly deploy with column input.

Ready
18th Feb 2004, 18:29
Not an excuse,

But it's been more than 10 years now since I last flew the 757, and I stand to be corrected, but I think they were not roll spoilers.

None of them moves opposite to aileron inputs, in the air or on the ground. They are used as speed brake only in the air, all going out at the same time.

Again it's been quite a few years. Any 757 drivers on that one? Mono, maybe you're one or used to be one, so I'll just take your words for it in that case unless.........

Caio!!

Iceman49
20th Feb 2004, 06:20
We teach primarily rudder, and only enough aileron to keep the wing from coming up. 0 roll rate at lift off. 13 years A320

Hand Solo
20th Feb 2004, 07:14
Our company manuals say side stick inputs are permitted during the take off roll, but only up to a deflection equivalent to half the cross on the PFD, with no roll input at rotation. This is a lovely idea apart from the fact that it doesn't work in reality and results in immediate lifting of the upwind wing as the wheels leave the ground before normal law has blended in. A more realistic procedure is to maintain a very slight into wind roll command (about an eighth to a quarter of the cross width max) on rotation then kind of pull and roll a bit, up to a max of half the cross width before centering the stick as your reach the target pitch attitude. The cross itself travels in a banana shape on the PFD. Sounds complicated but its actually very easy to fly accurately, prevents a wing lifting after take off and doesn't deploy the spoilers.

HOMER SIMPSONS LOVECHILD
20th Feb 2004, 08:28
"Ready" those 10 years off the 757 have not been kind to you!
The 75' most certainly does and always did have spoiler assisted roll.Any more than about 2.5 units yoke deflection on the roll will deploy them.

Ready
21st Feb 2004, 13:37
Thanks to you all!

Well in my 757 days I had it all wrong then. Not because of lack of aircraft systems, but I did not know then that the technique would be different with or without roll spoilers.

Unfortunately I cannot go back in time, but again thanks, I've learned some more here, I mean the technique as such. I fly the a300 at the moment and my next airplane will be the a320 (I'll be actually teaching it). I'll make a copy of all that good stuff that you guys wrote.

Happy crosswinds!

BEagle
21st Feb 2004, 13:57
I thought that the whole idea of manouvre demand was that, if you don't demand manoeuvre, then it won't manoeuvre?

Why go against the FCOM? Surely the manufacturer's advice is more appropriate than " 'cos that's what we did on the 707"!.....

A different question - is the A321 more demanding to land than the A320 or A319? The reason I ask is that, as SLF, I've suffered 2 bone-jarring 'arrivals' courtesy of Lufthansa in A321s but never in the 300, 319, 320, CRJ or 737!

Maxrev
21st Feb 2004, 14:32
I was taught a technique similar to Hand Solo's, meaning (in the instructor's words) just a 'smidgen' of stick into wind, and veeery slowly rolling it off after rotation. Works for me.

Beagle, the 321 is just a long sucker. Remember that and you'll be okay. All the 320 family aircraft can be a handful in a gusty approach - it's not unheard of to be deflecting the stick all the way at times, which unerved me greatly to begin with.

You get used to it though, and Boeing cockpits seem cramped, fussy and dated after a 'Bus.

320DRIVER
24th Feb 2004, 00:44
About the A321 landing; could it be cos when your're landing the A321 with A319/A320 attitude, your wheels will be underground (longer fusleage) for the same cockpit height above the runway surface at touchdown?

Never flew the '21 so might be total pigswill...

mcdhu
24th Feb 2004, 02:45
No, 320Driver, you're right, but if you use the radalt callout (which gives you wheelheight) as a cue for your flare, you won't go far wrong whichever you fly.

Cheers,
mcdhu

TopBunk
24th Feb 2004, 16:05
Maxrev

All the 320 family aircraft can be a handful in a gusty approach - it's not unheard of to be deflecting the stick all the way at times, which unerved me greatly to begin with.

I wouldn't disagree with you about them being a handful on gusty days, and would personally prefer them to go to direct law in roll with the gear down, but re the above, don't forget that the stick is demanding rate of roll/pitch and not surface position until the stick is held there long enough. Therefore full sidestick does not equal aileron/spoilers at the limit of their travel.

Dream Land
25th Feb 2004, 01:23
A321 landing: In my opinion the A321 is much easier to land, definitely a more stable platform, rolls on like butter.:D

DL

GearDown&Locked
25th Feb 2004, 04:01
Related to the A321 landing;

Some 4 to 6 months ago, a TAP A321 tried to land in LPPT in heavy and gusty crosswind, made the crab technique until some 10/15 ft and almost hit the ground with the right wing when lined up w/ the runway, caused by a quick and sudden roll movement; the second attempt was even worse, w/ the a/c swerving along the runway, right after lining up, the right wing, again, dangerously close to the tarmac. In both cases the a/c never touched down, and it took a lot of sidestick'in to make the bus "behave" again. I can imagine that an A320 in the same situation would be a lot worse, due probably to inertial force diferences between the two a/c's.

BEagle
25th Feb 2004, 06:26
Which makes me wonder just how safe it is for 'average' pilots to hop straight from a 320 to a 319 and then a 321.

Conditions for the last impact with tarmac which a LH 321 pilot subjected me to were hardly demanding, good vis, 6 knots down the runway and no cross-wind.....

Won't be able to check it out on my next trip away - all my LH flights will be in 737s, unfortunately.

OPEN CLB
25th Feb 2004, 22:44
Conditions for the last impact with tarmac which a LH 321 pilot subjected me to were hardly demanding, good vis, 6 knots down the runway and no cross-wind.....


Guess thats more a mental problem. You simply believe that it can't go wrong in that good conditions...and WHAM, gravitation strikes back.
Honestly, its happend to me as well. Gusty SW wind on 27R at LHR; a barely noticable smooth touchdown.
A day later at my home base in central Europe, clear skies and absolutely no wind; resulted in a flight/landing-check of the MLG struts....:}