Side Slip (wing down/cross control) Landing Technique on Airbus (A330)
Bloggsy-----nope not a toy plane like the Lear, wouldn't mind though.
Surely the differential thrust would be f all?
Anyway why would you want to do it anyway, surely the rudder is sufficient.....
Do you do it in the 717? Is it an approved method?
Surely the differential thrust would be f all?
Anyway why would you want to do it anyway, surely the rudder is sufficient.....
Do you do it in the 717? Is it an approved method?
Boeing doesnt seem to have an issue programming wing down for the autoland.
As long as its not excessive there's nothing wrong with it, it produces a far more stable, predictable result.
Of course if you don't have the 'courage' to kick it out at the last minute
As long as its not excessive there's nothing wrong with it, it produces a far more stable, predictable result.
Of course if you don't have the 'courage' to kick it out at the last minute
Once again the crusty old ex-RAF types who have acquired the necessary skills for a last-moment juggling exercise with rudder and stick pour scorn on the inadequates who use easier methods.
My confidence in Xwinds was almost completely destroyed by the RAF technique in Chipmunks. Later in Scotland I was taught that the crossed controls method was the professional way to make smooth controlled landings in Hebridean gales at minimum discomfort for passengers.
Later I was able to satisfy myself that the technique works superbly on machines as diverse as the Chipmunk, Tiger Moth, Viscount, B767 - and have no doubt Airbus as well although I have not had the pleasure.
As an ex-TRE I treasure a note from a very experienced ex-RAF pilot thanking me for having undone his service brainwashing after he had carried out a max Xwind landing on the 757.
There is no question in my mind but that the controlled slip (not wing-down!) is by far the easiest method to teach and is likely to have the most successful outcome.
The B767 autopilot gives a particularly polished demonstration.
My confidence in Xwinds was almost completely destroyed by the RAF technique in Chipmunks. Later in Scotland I was taught that the crossed controls method was the professional way to make smooth controlled landings in Hebridean gales at minimum discomfort for passengers.
Later I was able to satisfy myself that the technique works superbly on machines as diverse as the Chipmunk, Tiger Moth, Viscount, B767 - and have no doubt Airbus as well although I have not had the pleasure.
As an ex-TRE I treasure a note from a very experienced ex-RAF pilot thanking me for having undone his service brainwashing after he had carried out a max Xwind landing on the 757.
There is no question in my mind but that the controlled slip (not wing-down!) is by far the easiest method to teach and is likely to have the most successful outcome.
The B767 autopilot gives a particularly polished demonstration.
Originally Posted by scotbill
There is no question in my mind but that the controlled slip (not wing-down!)
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What is so difficult about removing the crab I fail to understand. The only problem I see is doing it too early causing a downwind drift. Then you use the bank anyway. You are permitted to land with 5 degrees of crab. Suppose you were late in removing the crab on touchdown the aircraft will straighten itself because of CG but if you were coming with wing down it may be more than 5 degrees and during flare you may risk engine contact. In airbus you are not dealing with flight controls directly but asking computers to give rate of roll so it positions ailerons, spoilers and rudder accordingly even if you neutralise the stick, yaw damper is positioning the rudder as long as wing is down and you need to fly against that. May be that is not desired so is not recommended.
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villas,
Exactly the same in a Boeing.
The probable reason is, if you fly with big side slip angles (early in the approach) on Airbus, you won't know when you are about to run out of aileron control (full deflection) due no feed back of FBW controlled aileron position. On all Boeings (including 777) it's obvious by the amount of control wheel necessary.
yaw damper is positioning the rudder as long as wing is down and you need to fly against that.
May be that is not desired so is not recommended.
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Goldenrivett
There is a little difference with non FBW. In that Yaw damper action may be same but the aileron and spoilers you directly control. In airbus the computer is in opposition to your action. So there is conflict. May be what you say also is possible. That is the reason I recommend SOP. You want to do something else refer to Airbus industry. I have done it on many issues and got clarifications from them. Doing something different without all the answers I am not comfortable with.
There is a little difference with non FBW. In that Yaw damper action may be same but the aileron and spoilers you directly control. In airbus the computer is in opposition to your action. So there is conflict. May be what you say also is possible. That is the reason I recommend SOP. You want to do something else refer to Airbus industry. I have done it on many issues and got clarifications from them. Doing something different without all the answers I am not comfortable with.
Last edited by vilas; 14th Nov 2014 at 13:46. Reason: addition
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ACMS...
Do you realize that many people learned to fly in the actual airplane and not in a sim? Do you realize that many checkrides are flown and that a max crosswind is not available at the time of the checkride and you can still get a type rating?
AS to assymetric thrust on planes with tail mounted engines...yes, you actually have assymetric thrust and guess what, WHEN AN ENGINE QUITS you need full rudder at some times.
AS to passenger comfort, slipping an airplane can be a bit uncomfortable.
And what really gets me is that pilots today don't seem to understand that the wind at 300' afe is not the same as it is at touchdown, so you are still FUTZING with the thing .
So if you have crabbed, can see a wind sock and can "KICK IT STRAIGHT" you are actually DOING LESS WORK than the slip method.
AS to NON APPROVED procedures. IF you don't want to use assymetric thrust, don't. But if you ever do, you will find you have more options.
And all those fancy autopilots seem to have lower crosswind limits for their landing than humans do...why is that? ;-)
Go Get Em bubbers, fly with you anytime!
Do you realize that many people learned to fly in the actual airplane and not in a sim? Do you realize that many checkrides are flown and that a max crosswind is not available at the time of the checkride and you can still get a type rating?
AS to assymetric thrust on planes with tail mounted engines...yes, you actually have assymetric thrust and guess what, WHEN AN ENGINE QUITS you need full rudder at some times.
AS to passenger comfort, slipping an airplane can be a bit uncomfortable.
And what really gets me is that pilots today don't seem to understand that the wind at 300' afe is not the same as it is at touchdown, so you are still FUTZING with the thing .
So if you have crabbed, can see a wind sock and can "KICK IT STRAIGHT" you are actually DOING LESS WORK than the slip method.
AS to NON APPROVED procedures. IF you don't want to use assymetric thrust, don't. But if you ever do, you will find you have more options.
And all those fancy autopilots seem to have lower crosswind limits for their landing than humans do...why is that? ;-)
Go Get Em bubbers, fly with you anytime!
Yes I came from a time before flight sims and we had to learn in the Aircraft as well, I clearly remember having to do crosswind landings during conversion in the Aircraft.
I still can't believe neither you or the new FO had landed in a good crosswind and they signed you off as safe IN ALL CONDITIONS? Surely you should have found suitable conditions to be trained in to a competent standard, even if that meant waiting or flying off to another Airfield to find a crosswind....
Wouldn't happen today, in my 777 command 14 years ago we had to demonstrate competence with a 38kt crosswind at Cat 1 minima and a wet runway.....if I couldn't do it safely I would not have passed....
As for the differential thrust idea, great but I've never been trained by Boeing Fokker or Airbus to use that style ( mainly as they prefer the use of Autothrust ) and I don't think it would be wise to stuff around trying......Rudder and Ailerons work just fine for me up to Max crosswind.
Yes I realise the 300' wind is most likely different to the surface wind....but thanks for the heads up.
p.s. The 777 Autoland crosswind limit 38 kts ( NON AWO ) is the same as the Pilot limit of 38kts
I still can't believe neither you or the new FO had landed in a good crosswind and they signed you off as safe IN ALL CONDITIONS? Surely you should have found suitable conditions to be trained in to a competent standard, even if that meant waiting or flying off to another Airfield to find a crosswind....
Wouldn't happen today, in my 777 command 14 years ago we had to demonstrate competence with a 38kt crosswind at Cat 1 minima and a wet runway.....if I couldn't do it safely I would not have passed....
As for the differential thrust idea, great but I've never been trained by Boeing Fokker or Airbus to use that style ( mainly as they prefer the use of Autothrust ) and I don't think it would be wise to stuff around trying......Rudder and Ailerons work just fine for me up to Max crosswind.
Yes I realise the 300' wind is most likely different to the surface wind....but thanks for the heads up.
p.s. The 777 Autoland crosswind limit 38 kts ( NON AWO ) is the same as the Pilot limit of 38kts
Last edited by ACMS; 15th Nov 2014 at 01:34.
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Back when we were flying dozens of different types of aircraft while waiting for our shot at the airlines when noone was hiring we were competent to fly so checking out in a Citation Jet or Lear was done quickly with your charter company or what ever you were doing. No ground school, no formal training, just learning the differences and taking a check ride. We all could read a manual and get in the airplane and after a couple flight were competent in that type. No training on how to land or SOP's because we were expected to fly a single, twin cessna, Beach 18, Citation any time a flight came up. The Lear I was flying that night I just started flying so never got to do a cross wind landing until then. Since I wanted to make sure I had enough rudder to compensate for the crosswind I used some upwind thrust. If you don't think fuselage mounted engines require much rudder with assymetrical thrust you are wrong. Try a V1 cut with no rudder some day.
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ACMS
Every time I got a new plane, I would read the aircraft flight manual, especially the introduction.
It always said that the book was no substitute for an experienced pilot.
Boeing didn't teach me to fly.
I was thinking about one of the airports I fly into on a regular basis. KDCA. Its approach to the south would not lend itself to the slip method of crosswind landing. I'm sure some of you know what I'm talking about .
So, don't hit the wing, or the engines, keep it in the center of the runway and do it any way you can.
Every time I got a new plane, I would read the aircraft flight manual, especially the introduction.
It always said that the book was no substitute for an experienced pilot.
Boeing didn't teach me to fly.
I was thinking about one of the airports I fly into on a regular basis. KDCA. Its approach to the south would not lend itself to the slip method of crosswind landing. I'm sure some of you know what I'm talking about .
So, don't hit the wing, or the engines, keep it in the center of the runway and do it any way you can.
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Bubbers
I know that you like nothing more than telling people how great aviators were, back in your day (we're going back quite some time, too). The simple fact remains that having zero training as you transition from one jet to another is foolhardy by anyones standards. That's why you'd never get away with it now. Oh, but never mind, that must be because your generation were so much more skilled, back then. That'll explain why flying was so much safer 40 years ago than it is today.
However, that's completely irrelevant.
What is relevant, is your assertion that a LR provides asymmetric thrust on approach. Ha, having flown one, and also having landed one with an engine inop, I must ask you whether you were joking? The asymmetric thrust experienced during approach power settings needs nary the slightest squeeze of rudder. To pretend that you need it as an option on approach is, frankly, laughable. To even consider it as a possible option would suggest that you're flying too many types, therefore unable to apply the basic aerodynamic principles pertinent to the one you're sat in.
We're not talking about V1 cuts with 'no rudder'. We're talking about differential thrust on a CL thrust aircraft on approach. With rudder.
Can you do a checkride on a LR to remove your CLT limitation? I didn't think so.
However, that's completely irrelevant.
What is relevant, is your assertion that a LR provides asymmetric thrust on approach. Ha, having flown one, and also having landed one with an engine inop, I must ask you whether you were joking? The asymmetric thrust experienced during approach power settings needs nary the slightest squeeze of rudder. To pretend that you need it as an option on approach is, frankly, laughable. To even consider it as a possible option would suggest that you're flying too many types, therefore unable to apply the basic aerodynamic principles pertinent to the one you're sat in.
We're not talking about V1 cuts with 'no rudder'. We're talking about differential thrust on a CL thrust aircraft on approach. With rudder.
Can you do a checkride on a LR to remove your CLT limitation? I didn't think so.
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mcnugget
are you saying flying a learjet means you are flying a center line thrust airplane?
tell me, what other planes with engines mounted on the fuselage are center line thrust?
are you saying flying a learjet means you are flying a center line thrust airplane?
tell me, what other planes with engines mounted on the fuselage are center line thrust?
Quote:
Originally Posted by scotbill
There is no question in my mind but that the controlled slip (not wing-down!)
This'll be good. Please explain the wings-level controlled slip.
Originally Posted by scotbill
There is no question in my mind but that the controlled slip (not wing-down!)
This'll be good. Please explain the wings-level controlled slip.
A question of terminology. "Wing down" suggests you could be placing wingtips or pods in jeopardy whereas a correctly flown controlled slip landing should see bank angles of the order of no more than 2 degrees.
Similarly it amazes me that any professional pilot can use words like "kick" in connection with control of an aircraft in the flare. What do you think would be the effect in Row 40 if your student takes it literally? (Yes, someone did do it to me in a 757!)
The single greatest disadvantage of the last-moment de-crab is that, if mis-judged, it leaves the aircraft drifting downwind and the pilot running out of ideas (particularly if carrying excessive speed). A common reaction is to push the nose down in an attempt to get on the ground. If this means that the touchdown is nosewheel first, it can cause serious damage to the airframe.
While I eventually did acquire the ability to de-crab early in my career, there is no question in my mind that controlled slip builds student confidence earlier and is more likely to lead to successful outcomes.
Why accept that touchdown with 5 degree crab angles is OK if you can ensure a smooth normal flare and touchdown on centre-line?
Glendalegoon
I have yet to find a runway where you could not use controlled slip. The whole concept is based on maintaining runway centre line and gradually intoducing opposite aileron and rudder in the last 100 feet or so. Even displaced centre lines allow a normal approach eventually.
Please explain what is different about Washington?
I have yet to find a runway where you could not use controlled slip. The whole concept is based on maintaining runway centre line and gradually intoducing opposite aileron and rudder in the last 100 feet or so. Even displaced centre lines allow a normal approach eventually.
Please explain what is different about Washington?
Yep I've said it before in this thread and I'll say it again......
I only introduce the "de crab" slip during the flare, I don't fly a sideslip approach.....I've seen it done in Jets and I didn't like it.
I've flown the IGS in HK with a gusty crosswind lining up at 500' on approach around the corner between the roof tops in a 744 at 160 KIAS during a Typhoon.
Then used the Boeing trained "de crab" manoeuvre in the flare
I'm still here alive and the Aircraft ain't bent.....
I only introduce the "de crab" slip during the flare, I don't fly a sideslip approach.....I've seen it done in Jets and I didn't like it.
I've flown the IGS in HK with a gusty crosswind lining up at 500' on approach around the corner between the roof tops in a 744 at 160 KIAS during a Typhoon.
Then used the Boeing trained "de crab" manoeuvre in the flare
I'm still here alive and the Aircraft ain't bent.....
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McNugget, a quick check of FAR 61 says a multiengine rating with no centerline thrust limitation can be given in any aircraft that has a VMC. The Lear has a VMC as does the MD80 and B727.
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Asymmetric thrust?
Still not seeing the requirement for, or advantage of this "upwind asymmetric thrust" concept (or whatever you wish to call it). Could one of the virtuosos of this technique kindly explain it in detail? Is it only peculiar to some types?
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Titaniumwings
You started the thread in relation to A330 and was applicable to Airbus FBW in general. Now it has drifted out of that parameter and now individual techniques and quirks are being discussed. None of which is applicable to Airbus. I hope you have already switched off.
You started the thread in relation to A330 and was applicable to Airbus FBW in general. Now it has drifted out of that parameter and now individual techniques and quirks are being discussed. None of which is applicable to Airbus. I hope you have already switched off.
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I have big ears and always like to listen. Now I am listening to aviators all around the world the comparing the pros n cons of the side slip vs crab-decrab method. The passion of everyone loving their art is really heartening and invigorating. Always love listening to aviator's stories and their craft.
I was taught both when I first started flying. I also read the pros n cons of both. I saw both being practiced in the Boeing and many other aircrafts but just to have a particular discussion on Airbus as its FBW has certain characteristics which make the side slip method quite a topic for discussion.
This is especially so because both the side-slip and crab-decrab method are predicated in Boeing FCTM but Airbus specifically predicate crab-decrab method in their FCTM without any restriction or limitation being mentioned anywhere else. I do not have a problem with Airbus recommendation but for those who ever wish to try the side-slip method on Airbus, an understanding of the aircraft Law would be beneficial to the action-reaction/see n react that thing pilot does. In the real world not thoroughly understanding this part may not result in critical consequences. I just like to know the aircraft intimately. BTW I used the crab-decrab method but I don't judge those who use side-slip. I like to keep things simple and just follow the recommendations whenever I can but when someone asks me I wish to be in a position to tell yes and no with the corresponding reasoning and explanations especially technically.
ps: But if someone has time and free then consider the question that I last posted in #44. I believe there is a group which has the following interpretation:
In a steady state crosswind with Airbus FBW Lateral Law the roll rate is ordered by the side stick. Computer will order rudder output for turn coordination (centering the "ball") and yaw damping. Hence in wings level condition and without sidestick input, 0 roll rate will be ordered.
Now here is the key: Will this order be continued when pilot give a rudder input. In other words will the aircraft's computer order the rest of the control surfaces to give 0 bank as the sidestick still orders "0" roll rate? From what I read, I believe some people believe this and expect the wings to be level when they input the rudder in decrabbing. (The other interpretation will have the pilot putting in a coordinated aileron with the rudder input when decrabbing).
Should this be the case then consider when you are turning the aircraft with 5 degree angle of bank then you neutralise the sidestick. Aircraft will order the rudder accordingly to coordinate the turn. Now you put in rudder input, will the computer still order the rest of the control surfaces for "0" change in roll rate to maintain your 5 degree angle of bank? (some may even take it as "in-between" the 2)
In the real world, wind is not constant and pilot will do whatever is necessary(inputs accordingly) to keep the heading down the runway and aileron correspondingly to keep the aircraft on the centreline.
Nonetheless if the interpretation of the aircraft reaction is valid then there is a bearing on the "way" the aircraft can be "used" to the the sideslip method. This thread is started by the comment that I have heard some people saying that Airbus can't do sideslip method for landing, by that I mean side-slipping the aircraft at 400'. For the purpose of this discussion let's simplify the comparison between crab-decrab (as most may have known it) and sideslip to mean sideslipping starting at short finals of below 400' but above flare height. It is also clear to me that most (if not all) know how to fly their aircraft and do their jobs. I and we are not contra-recommending any change in techniques, just a simple exploration of the aircraft that we love.
Thank you for your time and consideration.
I was taught both when I first started flying. I also read the pros n cons of both. I saw both being practiced in the Boeing and many other aircrafts but just to have a particular discussion on Airbus as its FBW has certain characteristics which make the side slip method quite a topic for discussion.
This is especially so because both the side-slip and crab-decrab method are predicated in Boeing FCTM but Airbus specifically predicate crab-decrab method in their FCTM without any restriction or limitation being mentioned anywhere else. I do not have a problem with Airbus recommendation but for those who ever wish to try the side-slip method on Airbus, an understanding of the aircraft Law would be beneficial to the action-reaction/see n react that thing pilot does. In the real world not thoroughly understanding this part may not result in critical consequences. I just like to know the aircraft intimately. BTW I used the crab-decrab method but I don't judge those who use side-slip. I like to keep things simple and just follow the recommendations whenever I can but when someone asks me I wish to be in a position to tell yes and no with the corresponding reasoning and explanations especially technically.
ps: But if someone has time and free then consider the question that I last posted in #44. I believe there is a group which has the following interpretation:
In a steady state crosswind with Airbus FBW Lateral Law the roll rate is ordered by the side stick. Computer will order rudder output for turn coordination (centering the "ball") and yaw damping. Hence in wings level condition and without sidestick input, 0 roll rate will be ordered.
Now here is the key: Will this order be continued when pilot give a rudder input. In other words will the aircraft's computer order the rest of the control surfaces to give 0 bank as the sidestick still orders "0" roll rate? From what I read, I believe some people believe this and expect the wings to be level when they input the rudder in decrabbing. (The other interpretation will have the pilot putting in a coordinated aileron with the rudder input when decrabbing).
Should this be the case then consider when you are turning the aircraft with 5 degree angle of bank then you neutralise the sidestick. Aircraft will order the rudder accordingly to coordinate the turn. Now you put in rudder input, will the computer still order the rest of the control surfaces for "0" change in roll rate to maintain your 5 degree angle of bank? (some may even take it as "in-between" the 2)
In the real world, wind is not constant and pilot will do whatever is necessary(inputs accordingly) to keep the heading down the runway and aileron correspondingly to keep the aircraft on the centreline.
Nonetheless if the interpretation of the aircraft reaction is valid then there is a bearing on the "way" the aircraft can be "used" to the the sideslip method. This thread is started by the comment that I have heard some people saying that Airbus can't do sideslip method for landing, by that I mean side-slipping the aircraft at 400'. For the purpose of this discussion let's simplify the comparison between crab-decrab (as most may have known it) and sideslip to mean sideslipping starting at short finals of below 400' but above flare height. It is also clear to me that most (if not all) know how to fly their aircraft and do their jobs. I and we are not contra-recommending any change in techniques, just a simple exploration of the aircraft that we love.
Thank you for your time and consideration.
Last edited by titaniumwings; 15th Nov 2014 at 13:26.