Airbus A/C flaring on landing

[leewan]

I've generally noticed that Airbus aircraft tend to flare with a high AoA compared to other makes, sometimes to the point of near tailstrike. I've even seen a few A330s bounce upon landing due to this "phenomena" . This is irregardless of operator. My question is: Is this steep flare a component of the autolanding software or a Airbus FCOM stipulated thing that they should flare with high AoA ?:)

[Founder]

no its not... I fly A321 and we have maximum pitch of 7,5 degrees but I almost never go above 5 degrees when I flare. I dont know if that's high considering other aircraft but I wouldn't think so...

The autoland pitches about 4,5 - 6° depending on conditions...

[villian]

Yes,but you probably add some app speed to reduce pitch increasing landing distance.

do you make this addition in autoland ? i do.

[Carnage Matey!]

Never seen increased speed used for that purpose on an A320 autoland in my company, nor were there ever pitch attitudes routinely in excess of 5 degrees.

[FatFlyer]

Perhaps they landing with flap 3 instead of full to save fuel/noise which gives a higher nose attitude on approach/flare?

Some operators specify on A321 (due to long body to avoid tailstrike?) checking that Vapp is at least 5 knots above Vls and if not to adjust it to that

[J.O.]

If the nose is being held that high, whether landing flap 3 or flap full, the flare is being held off too long, i.e. improper landing technique. The best landing technique is one which closely emulates the autoland technique.

Another common problem (from my perspective) is leaving the thrust up too long in the flare. More than two or three "Retard" calls is a clue that the thrust was left up too long. Personally, it's very rare that I don't close the thrust levers passing 20 ft on the autocallout, again just like the autoland.

[TyroPicard]

More than two or three "Retard" calls is a clue that the thrust was left up too long.
On a normal day in the A320 Airbus recommend you should close the T/L promptly at 30' and there should be no "RETARD" reminder. If you leave it too late the thrust starts to increase to maintain target speed in the flare, increasing the landing distance. On an autoland the RETARD call is an instruction and not a reminder - the A/THR will already have reduced thrust.

[mourgo]

The 330 & 340 have a natural tendency to flare with a high AoA. You wont notice this in a 320 series. If you have a bit of a tail wind you will hear the RETARD call out about 6-8 times.

[leewan]

The 330 & 340 have a natural tendency to flare with a high AoA.

So, is this a result of the autoland software or pilot input ?

[TyroPicard]

All aircraft land with a high AoA - do you mean pitch attitude?

[divinehover]

1-There is no difference between Autoland and manually flown landing attitude.

2-There is no significant difference between Airbus and any other swept wing large jet in terms of it's landing attitude.

[mourgo]

No.. the airbus 330-340 land with a higher AoA than other planes. Manual or auto doesnt matter.

YouTube - A-330 Landing (http://www.youtube.com/watch?v=G_fhn_zuovM)

Observe this video. I fly both 330 and 320.

[TyroPicard]

How do you know the AoA? Do you mean pitch attitude?

[leewan]

My bad. Got confused. I meant the pitch attitude.:ooh:

[guiones]

Mourgo:

The landing on both the A320 series, A330 series and all Airbus FBW(including the A380) should be a change in pitch and let the aircraft settle down, not a prolonged flare like the video you posted. Proper pitch change and thrust reduction will reward you with a smooth landing on the landing zone and not a prolonged flare looking for the ilusive greaser. Do this and you will have constant smooth safe landings, just watch the auto pilot do it and emulate it.

G

[swedflyer]

You can see the AoA in the ACMS, if it's of any interest....

[Exaviator]

I am showing my age here a bit but on the A-300 (B4) the smoothest landings were achieved by easing forward on the controls after the flair had been established, very similar to landing the 727-200. Worked every time.:ok:

[EpsilonVaz]

My company encourages Config 3 approaches/landings where possible. Sitting at the hold watching company aircraft land, I very often think "that's quite a high pitch!", but apparently that's a competely normal perception if you're watching an A319 landing in Config 3!.

[Capt Turbo]

First the background: Airbus gives 3 landing distance tables, "manual/manual", "manual/autobrake" (FCOM 2.03) and "autoland/autobrake".
"Manual/manual" is the minimum landing distance based on certification flight tests. You arrive over the "screen" (50´) with Vref (Vls), retard the thrust and rotate the aircraft along a constant flight path resulting in a touchdown speed of Vls minus 7-8 kts and a relatively high pitch attitude. Derotation is positive and max brakes are applied without reverse.
"Autoland" includes the addition of the A/THR +5kts and that is why there is a difference between the FCOM 2 and QRH values.
Assuming that all systems work as per design the only variables affecting landing distance are landing GS and residual thrust (+ some wind effects during ground roll).
This is why Airbus recommends retarding thrust at 30´/40´and before the retard reminder, but....

Line pilots are reluctant to do this :confused:. Many prefer to keep the (auto)thrust in , sometimes even to touchdown, with a baloon, a 3-pointer, a prolonged flare or firm touchdown and excessive landing roll as the result. And this is not only a French problem; the West Coast jocks are even worse, if anything.

During countless base-flight landings with pilots having between 100 and 20.000 hrs total stick time I see a clear tendency: The thrust is retarded too late for an easy landing (old hands and Boing/MD to Airbus converts are most pronounced).
Once they retard as per FCOM and make a smooth rotation the whole thing falls into place and the landing becomes simple. The exception is if you have a lot of ballast concentrated in the rear of an empty aircraft (which is often the case during base flights), then the bird becomes more responsive and does not require a positive flare, but this configuration is rare during normal ops.

There are a few Airbus diff´s: Early A320s require a more positive flare, A321 - having a different flap slot - require less rotation and 330/340 settles nicely with 40´ retardation and a smooth rotation.

But is late retard a No-no? If the actual headwind is stronger than the FMS entered value GS mini may give too small an addition. If the wind is gusting greatly or downdraft is present. Then is may be prudent to delay the retardation at the expense of longer landing, but dont do it as a routine. And not in tailwind....and not with Conf 3 or less.

An operator had a serious problem with hard landings on a particular (non-airbus) type. I made a FDR study of the hard landings and all had a touchdown attitude of 4 dg or less. It turned out that the pilots had been taught a "power-on/no flare" technique ever since the CFI converted from straight wing props to jet some generations ago.:ugh:
You may have heard that "this new aircraft require a totally different landig technique"....Bullocks! I have flown supersonic deltas to LSAs and a lot in between and the fundamentals are the same (except those with boundary layer suction and blown flaps).

Remember: An aircraft is an aircraft is an aircraft! Chop the thrust at FCOM value, rotate a few degrees (typically from 3 dg ANU to 5-6 dg ANU depending on CoG) and wait for the kiss. Even if the flare is a bit longer than you are used to, the stopping distance is not affected much, if you got rid of the thrust passing the threshold.:ok:

Next time in the sim, ask your friendly TRE if you can practise a few landings (yes...I know..but anyway..).

Happy landings!

Capt T.

[Mr Levitator]

could this be to do with the fact Airbus fly 1.15 Vs (guess) on app due to having FBW where as Boeings fly 1.3 Vs? This would imply both high pitch attitude and AoA in the flare for Airbus.

[FlightDetent]

No, Vs1g is deemed (by certification authorities) equivalent to Vs. Vref is locked at 1,3 Vs1g. Typical Vapp is Vref+5 kt.

Yours,
FD (the un-real)

[salamanderpress]

Looking at it as a simple Maths problem. If descent angle is 3 deg, you need to change body angle by 3 deg to get a level flight path IF the speed was constant. Wind additives to V Approach would have the effect of giving you a virtually constant body angle (for an unadjusted V App, you would have a higher body angle due to a lower rate of descent.)

at the COMPLETION of the flare, the body angle would be higher than required to fly level, because you would have been using additional lift coefficient (angle of attack) to change flight path from descent to level. If you had a speed vector which you could point at the aimpoint during approach and then at the horizon on completion of flare, you would get a perfect touchdown every time, regardless of speed. Every landing technique aims at this trajectory, with different ways of briefing for it, with the addition of the speed decay from V App to a few knots below.

Just my two bit worth

[PantLoad]

Captain Turbo,

I wish I had had a copy of this post years ago to describe to others the correct way to land this plane! (I'm retired, now. Too late!)

Obviously, you read the manuals.

Well said!

Fly safe,


PantLoad

[AirRabbit]

Generally, I agree with all that Capt Turbo has said – but I would add the following … every airplane lands from the level flight attitude for the established configuration – supersonic fighters, light general airplanes, transport category airplanes from the smallest to the largest, regardless of the manufacturer. In other words if you were to level off at a height of 3 to 4 feet above the runway (that should be about 1 foot in a Cessna 152) and maintain that height all the way down the runway – without climbing or descending and without accelerating or decelerating (airspeed approximately 1.10 to 1.50 Vs for the existing configuration in ground effect) – you would have been at the proper attitude to land. It is THIS attitude that you should reach at the end of your flare – and your height above the runway should be down close to the runway – of course the higher you are when reaching this attitude, the longer you’ll take to get the wheels on the surface … not too good, particularly on shorter runways.

The other thing is that you should most assuredly have the throttle(s) at idle when the mains contact the surface – where you start to retard those throttles and how quickly you do it depends a lot on technique and individual airplane characteristics. Generally, if you cross the threshold at the proper height, at the proper speed, and begin a very gradual throttle reduction at that point – rotate to the proper flare attitude, taking no more than 3 seconds to reach that level flight attitude (3 – 4 feet) from the time you begin the flare, getting there at a speed of 1.10 to 1.50 Vs – continuing to retard the throttles – hold the airplane in that flared attitude for no more than 3 seconds, making sure the throttles hit the idle stop at touchdown – you will have made the “perfect” landing (contrary to those “know-it-alls” to say perfect landings don’t exist). This procedure will allow you to land at the proper distance down the runway, at the proper attitude, with sufficient airspeed to maintain directional control until you get the nose on the ground. I won’t tell you it will be the “grease job” landing everyone thinks is the mark of a good landing. No. It will be somewhat firm – but not at all unpleasant – and it works with headwind, tailwind, crosswind, light weights, heavy weights, and with any flap configuration. You’ll have enough vertical force to put the wheels on the runway – through any precipitation activity, but not so hard that the little old lady in 2A will have a coronary. However, it does take some knowledge of level flight attitudes at those conditions and some practice to achieve the proper attitude at the proper speed. Try it the next time you have a simulator session - and let us know how it works out.

[Jimmy Do Little]

I am showing my age here a bit but on the A-300 (B4) the smoothest landings were achieved by easing forward on the controls after the flair had been established

A321, A320 and A330 are exactly the same. Hate to sound like a book-worm, but a careful read of the FCOM (Remember, it's kind of translated from French to English, etc, etc) tells you the same. "...blah, blah, blah....landing is conventional (for a TRANSPORT aircraft)....do not hold off nose wheel....derotate...etc, etc...' I recall the B727, 747 and (showing my age) the DC8, were pretty much the same deal. Arrest the sink rate, then derotate to the landing.

For the "Fly by Wire" ignorant, landing in the FBW Airbus series is in a "Control Law" that makes landings feel "...like any other aicraft..." sort of!


Vapp. Vapp ALWAYS includes an additional margin of speed to compensate for, lazy auto-thrust, Severe Icing, etc. Any other additions will be at the discretion of the pilots (For whatever reason) or a inputted as a result of a failure affecting aerodynamics (Flaps, etc).

In 15 years on FBW Airbus, I've seen more people get into trouble with landings (Pitch) when they didn't understand what Ground Speed Mini (GS Mini) did, or how it actually functioned. In fact, yesterday I had a guy want to REDUCE Vapp because GS Mini was doing EXACTLY what it was designed to do. In this case - had I allowed that reduction - the aircraft would have landed with a fairly high pitch attitude and - incidently -increased thrust. As a result, tail strike more probable.

Flaps Full or Flaps 3 is the same. The difference will be the approach speed (sometimes only a marginal difference) and a flatter pitch attitude at the commencement of Flare. Nonetheless, it's still a better landing (and according to the FCOM / FCTM) if you arrest the sink, then derotate the aircraft.

Generally, if you cross the threshold at the proper height, at the proper speed, and begin a very gradual throttle reduction at that point
I agree for most any other aircraft type. But, in the FBW Bus that thrust lever reduction (To Idle) can be a gentle reduction (Professional Technique) or simply yank them back to the Idle Stops (Frequently seen with the young folks who've never flown anything other). Whichever technique is used, it makes no difference in a FBW Bus, provided that the Auto-Thurst is being used for the landing.


I wish I had had a copy of this post years ago to describe to others the correct way to land this plane!

Like Airbus's "Golden Rule" number 1.... The Aircraft (Airbus) fly's like any other aircraft (Assuming Transport Type).


All of that said, no matter what you do during a landing, Airbus will always call you a "Retard, Retard, Retard".

[stilton]

'The Airbus fly's like any other Aircraft'


That may be the single most misleading statement ever printed in an Aircraft manual. :suspect:

[John Citizen]

I won’t tell you it will be the “grease job” landing everyone thinks is the mark of a good landing. No. It will be somewhat firm – but not at all unpleasant

Try and ask the passengers what makes a good landing.

I have heard many passengers comment on both smooth (grease job) and firm/hard/rough landings, but none ever made any comment at all about the touch down zone :confused:

You might say that the passengers of the flight which ran off the end of the runway did not have the opportunity to complain. However I do not think there will be much risk of this happening in fine weather conditions on a runway more than twice as long as legally required (which is already factored).

Argue against this point as much as you like, but just ask the passengers, who pay our wages / salary. Some are very fearful of flying want the overall experience to be as smooth as possible.

Sure, a greaser within the zone is ideal if you can do it everytime :ok:

[Jimmy Do Little]

http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gif[/IMG] I beg to differ....

Air France 358
Luftansa 2904
Southwest 1455
TACA 390
China 605
Qantas 1
Garuda 200
Lion Air 538
US Air 5050
Southwest 1248

All those passengers had comments about it!

[John Citizen]

Let me say this again :

I, my own ears, have not ever heard any passengers comment (speak directly to me) at all about the touch down zone.

I have had a look at those accidents you mention. I agree the passengers would have a lot to comment about.

However, these accidents involve other factors :
- adverse weather / windshear / storms / snow
- wet runway
- short runway / displaced threshold
- excessive approach speed / unstable approach
- speed brake retraction after touchdown
- idle reverse only / late deployment of reverse
- not in ideal landing configuration (flap setting)

Lion air 386 and US Air 5050 were both takeoff accidents :confused: Please explain how these are relevant to the discussion here.

For 2 of those accidents, Southwest 1248 and TACA 390, the aircraft actually did touch down in the zone but still crashed :eek:

A touchdown in the zone does not necessarily mean that you will never run off the runway and a long landing beyond the zone (as you see all the time) does not necessarily mean you will run off the runway and all die.

Let me say this again (assuming you fly a stable approach) :
I do not think there will be much risk of this happening (runway over run) in fine weather conditions on a runway more than twice as long as legally required if you land slightly beyond the zone.

Can you please find any examples where such has happened ?

Such conditions were not present in all those mentioned accidents above.

Don't get me wrong, I still believe you should attempt to touchdown in the zone every time but a smooth landing (to me) is also important. :ok:

However, in adverse conditions on a short runway, getting down in the zone suddenly becomes far more important now.

[Capt Turbo]

Where I was? In Toulouse with the old factory trying to teach a lot of guys how to do just these things ( between testing, delivering and manuals...).
Never left South Western France - people, food, wine, wx etc too good - but too old to see the fantastic 350 into service. Back out in the real world flying airline style for some of my old customers, retirement lurking round the corner.

You have a good one yourself..... T.

Ops, thought I send u a PM, anyway :uhoh: (and I fly pushbuttons.....)

[Lookleft]

Passengers are where the revenue for our wages come from but we work for the Chief Pilot and he wants me to put the wheels on the runway in the TDZ. He also looks at the FOQA data to make sure thats what his pilots are doing. Of course pax don't comment about the TDZ because they have no idea what it is. Even the manufacturers don't want "greasers" as it can lead to tailstrike if you try and "hold-off". They also want you on the runway dumping lift bringing it to a stop and their figures are based on putting it on the runway at the 300m mark. If you are happy to land "slightly beyond the TDZ" then you are in test pilot territory.

If affirmation of your flying skills by people unkown to you is important then what about the professional at the holding point who is going to be taking points off for a long landing?