A320 how to save this landing
 

friends, I was shooting a VOR approach today with 8 kts tailwind. things were fine upto 50ft, when suddenly wind died to zero. airplane started dropping, I pull the stick little up to increase the lift but controls were sluggish and didn't respond. just a second before touchdown airplane pitched up (may be the late response) and I cut the throttle. I had a 1.72g landing. :sad:
What could be ideal technique to save or rather reduce the 'damage' on this landing?

A go around?

Why would the aircraft drop if the tailwind dropped to zero?

After an excellent landing etc...

Just pulling back without increasing the thrust is inviting a tail strike. This is basic high rate of sink landing recovery. If it is really bad then a go around would be in order.

Don't close the thrust levers so early if you feel you have run out of energy. If you end up leaving them on too long and float deep, go around.

P

b737NGyyc, the autothrust (that would normally be ON even for manual landing on a Bus) should have taken care of that. I assume the problem was that the thrust levers were closed just as the autothrust reacted.

My simple non- Airbus twopence worth: Down to 50' (in this case) higher than normal Groundspeed due to the tailwind, so you have a higher than normal ROD to hold the glideslope, so the power's is back below normal headwind figures . Then at 50' you run into what is an effectively increasing headwind, Ground speed drops, ROD is still high, power's back ...if you or the AT don't increase the power you may start dropping short, if you pull the power off....

Standing by to be corrected.

As you can see from my pseudonym I don't fly the Airbus and never have but my experience with autothrust (throttles) is that they are rarely responsive enough to react to a situation such as this.

Having no experience on the Airbus I can only presume that they can be manually overridden if required by pushing the thrust levers forward. If the autothrust on the Airbus is responsive enough to handle this situation then that is great but from my experience pulling back and expecting the automation to save the landing is too much of a leap of faith for this stick and rudder guy.

All the bells and whistles are great but in some situations, such as this one, manual intervention is the way to go IMHO. More and more I see it on the line that there is too much reliance on the automation and more and more erosion of basic piloting skills.

IFLY
 

What did your Captain say?

He might be your best bet for some ideas on how to "save" the landing.

You have some very high time airbus drivers at Indigo, who I'm sure would be more than willing to share their experience with you.

I agree with some of the other comments made so far.. In that you can't rely on the automation to save the landing.

Keep a good eye on what the winds are doing... or have your PM to do that... watch for a trend and be ready to respond.

At what point did you take out the A/P? If you are low time, esp with the silly rules in India... where you as a F/O can't takeoff and and land unless on a special list (yes that right! a FO can NOT take off and land unless with a TRI/TRE)

You should consider taking out as much automation as you can... learning how to fly the aircraft by hand.. and building up the reflexes so it is second nature and you will see a trend developing much sooner.

Also, if things start to look bad... offer control back to the left... or GO AROUND.

If you ever fly something bigger... you really need to think about a tail strike as from what you say happened that was on the cards...

Just my 2 cents.

PT6A

I do not know the center of lift in relation to the gear in the A-320, often a pitch up at this hight to reduce the rate of decent can result in a higher rate of impact for the gear if it is aft of the axis the aircraft is pitching on. But as a few have said before, you did not have a resolution for the problem presented to you a GO-AROUND should have been the first instinct.

Hi IFLY_INDOGO,

My two pennies worth:

.. with 8 kts tailwind. things were fine upto 50ft, when suddenly wind died to zero. - If wind suddenly died to zero, air speed should have increased - Good.

airplane started dropping, - result of reducing ground speed and maintaining original ROD - Bad.

I pull the stick little up to increase the lift but controls were sluggish and didn't respond. - with increased airspeed, controls should have behaved normally - possibly an illusion due concentrating on touch down point -need to look further down the runway.

just a second before touchdown airplane pitched up (may be the late response) and I cut the throttle. - initiation of the flare was too late with high ROD.

I had a 1.72g landing. - Ouch.

What could be ideal technique to save or rather reduce the 'damage' on this landing? - With a tail wind and higher ROD - be prepared to flare a bit earlier and look further down runway to judge flare attitude change.

If you get into a similar situation again - do a "TOGA 10". Set TOGA power and rotate to 10 degs pitch up. This will prevent a tail strike on A320 / 319. After touch down, and when safely climbing away - do the normal "Go Around Flaps" rotating towards SRS / 15 degs.

As difficult as it can be to accept it, it's never too late to go around, even if you've touched down (although deciding to 'go around' when you're down to 50kts may not be such a good idea!)

If you feel the lift start to drop off, do NOT close the thrust levers, even if it's yelling retard. Keeping the thrust on (be it in SPEED or Manual), even until you touch down, can turn a heavy landing into just an uncomfortable landing.

Phase Advance is a great tool on the approach but remember that it doesn't work below 100ft RA.

Listen to others, learn from it and move on. Don't dwell on it and let it get you down!

Just out of curiosity, didn't you get any help from GS Mini here ?? AC energy should have remained as high as needed for sudden wind changes ...

Hi fredgrav,

"Ground speed mini" holds a suitable minimum ground speed based on the reported wind entered. With a tail wind on the approach you have a bigger ground speed - so GS Mini does nothing.

Is a 1.72G landing within limits? I.e. was an engineering inspection required? Not a bus driver myself so just wondering.

Hi rudder & studi,
sure, erroneously interpreted the decrease of TW as a lack of HW on final ... :sad:

If my memory serves me correctly its 1.8G that needs MX.

However a pilot SHOULD report a hard landing... as per the advice from the UK CAA as I don't think those readings are always spot on.

Would be curious if the orginal poster reported his landing.....

Hi IFLY INDIGO,

As has been said, the loss of tailwind would, everything else being equal, give an increase of IAS.

Did she bounce?

With VS higher than normal, flare needs to be started earlier (higher), and thrust retarded later (as has been said above), unless you are “fat” on IAS. If you realise you’ve left it too late, the only safe option is a go-around, because flaring will dig the main wheels in on the A320, just as on most aeroplanes with tricycle L/G.

A last-moment attempt to arrest the sink with a big burst of thrust is not something I would recommend − even if you are using manual thrust (my preference for most manual landings on the A320). It can lead to all kinds of problems, particularly on a short runway. If you do decide to continue, better to leave the power alone, but, if you have to ignore the “retard” call initially, don’t forget to do it once you are safely on the ground… Many of us have.

Yes, it’s easy for us to be wise while we ponder at our keyboards, or watch you from the briefing room window, but it doesn’t necessarily mean we would have done a better job than you did!

Chris

why is there a last FCOM engineering bulletin recommending not to move the thrust levers above climb?

I don't have that in my manual... Do you have the number and I can look it up...

PT6A

Never mind... found it... it is a FCOM bullitin not an OEB.

I felt a 1.98Gs the other day... it did hurt a bit, but aircraft was fine. AFAIK only above 2 or 2.6 requires maintenance action. In any case, we had the mechanic check the aircraft and it was fine.

Friends, thanks for your responses..

first, I was the captain myself :ouch:

Second, change of tailwind to nil wind was reported by my first officer, after reaching the bay. at 50ft my attention was all outside. so there could be a possibility of erroneous reporting.

third, ROD upto 50ft was about 700fpm. 3 deg descend, 2 whites 2 reds, GW about 61T. autothrust was on all the time. I disconnected AP at about 1000ft.

fourth, I did feel the increase in sink after crossing the threshold at 50ft.

my initial response to it was to pitch up a little bit to arrest the ROD. but it failed to respond. controls were sluggish.

I cut the power , because landing with power on with uncontrolled sink would have lead to greater bounch.

Now I recall we had a little bounch. And an aural 'PITCH' at touchdown.

post flight inspection, no sign of tailstrike.

of course I know, a go around would have been an ideal solution. but I started the thread with an objective to know what could have been done to reduce the g load on touchdown, assuming that a pilot would continue.

I feel g load could have been lesser if I had relaxed the pitch up demand, after finding no response intially. I dug the main wheels with constant demand.

Maybe you should learn to actually handfly the airplane and never have to embarass yourself again with a suck landing because of automation. Don't recall any landings going bad in the last several years of landings doing it manually. Actually it is kind of fun.

Did the aircraft produce a LOAD <15> report?

Did you mention this to anyone, logbook entry etc?

If you feel that the incident was bad enough to come on PPRUNE and talk about it like this.. I really hope you did.

Just been reading back over some hard landing reports on the 320.. that were not reported and went undetected and these have caused some serious issues on subsequent flights.

In short, if the landing feels overly hard report it! The 320 may not always produce a LOAD <15> depending on exact circumstances at the time of touch down / bounce it can mislead the software to the actual G load that was attained.

With regard to the winds.. would make a lot more sense if it shifted to a tailwind at 50 feet as opposed to the other way around.

You had a very lucky escape from your own account, and I just hope that the airplane that at a guess is back out flying has had a full inspection and is safe to be doing so.

Otherwise we could be looking at another report!

Well said P51:D

Why did you do that?

The best advise given thus far!

Careful PappyJ, some have come to grief by touching around, attempting to stop, then going around. VERY bad outcomes, usually a fireball! Now, if one touches down while "on the go", quite agree.

GF

Unless you've opened reversers, you can always go around.

Regarding manual increase of thrust levers above detent:

In SOME aircraft (dependant on mod status) if you are below 100' RA with the autothrust engaged and you nudge the levers above the detent, the autothrust will disconnect and you will get a huge increase in thrust as the engines chase the thrust lever position.

See FCOM 1.22.30 P62- subtlely hidden in the detail !:eek:

This will invariably lead to an unstable approach.:{

In this case wouldn't it be better just to accept a hard landing vs a go around?

The controls will of worked just as they were ment to... otherwise the poster would of been talking to the investigation team and not to PPRUNE.

It was just a classic case trying to make the best out of a bad approach and not making a go-around.

It is easy to blame the aircraft - when in most cases the problem is with the pilot, his training, the airline safety culture and the Aviation Authority.

In India at the moment the airlines are being forced to upgrade local co-pilots due to political pressure - these co-pilots have very very limited experience because as a co-pilot in India you are not released like a western co-pilot... You are NOT allowed to takeoff and land... unless with a TRE/TRI Line Training Captain... have x number of hours on the aircraft and both the Captain and FO have done further training.

In the western world you would of never been released to go out and fly with a line captain unless you could takeoff and land satisfactorily... that is where the system is flawed.

An Indian pilot having 500 hours on type is nothing like a western pilot with 500 hours on type... as the former will only have a fraction of the takeoffs and landings... Thus only part of the western pilots skillset.

Mastering the aircraft in various weather conditions takes practice, time and exposure - in the correct environment.

Otherwise we end up with a Captain and Co-pilot.. neither of which are overly proficient at handling the aircraft in all stages of flight.

PT6A

Commiserations on your experience. You are not the first A320 pilot to be caught out in this situation.

As I see it, the autothrust system would have reduced power to compensate for increasing airspeed as you descended out of the tailwind .In consequence you commenced the flare with less thrust set than you had anticipated and the aircraft behaved differently from what you had expected. Because your attention would not have been focussed on the engine instruments coming into the flare you would not have been aware of the low thrust level.

One solution (as others have already suggested) would have been to commence the flare slightly earlier and to a slightly higher pitch attitude while still avoiding a last-second snatch overpitch . Probably this would have still given you an uncomfortable arrival, but not as rugged as the one you describe.

Low level tailwinds and consequent shear are often encountered unexpectedly, and therefore may not be planned for in one's mental model of how to fly the approach and landing. So one has to be ready to adopt a different model. In this particular situation an early reversion to manual thrust as soon as a tailwind is identified would be beneficial. This would ensure full pilot control over power settings immediately prior to and in the flare, which of course you do not have when autothrust is in use.

The only thing that's gunna save you in a swept wing jet aeroplane when the arse drops out of it close to the ground is a handful of thrust, enough to feel it kick you in the back. If you don't feel the aeroplane accelerate you haven't used enough.

I've had a couple of events during the last few years when I got that ugly sinking feeling close to the ground and have flared and pushed up the thrust at the same time and the resulting touchdowns were quite good but if I hadn't done what I did then there would have been a couple of really hard landings.

Regards,
BH.

Hi IFLY-INDIGO,

The sensation which you thought was sluggish around 50 feet, was probably because :

"FLARE MODE

The flight mode changes to flare mode when the aircraft passes 50 feet RA as it descends to land.

The system memorizes the attitude at 50 feet, and that attitude becomes the initial reference for pitch attitude control."

Unlike a conventional aircraft which is trimmed to be speed stable in pitch, the Airbus below 50 feet is "trimmed" for the attitude you had then. So if it felt like you were sinking around 50 feet, because your attitude was too low, then you are stuck with that reference attitude, and it will "feel" heavier no matter what your speed is. Unlike a Boeing, which naturally pitches up with the application of power - your Airbus won't and it will still feel heavy.

Hi again, IFLY INDIGO,

Some of the recent responses seem to me to be a bit alarmist.

However, if your airline had a SESMA programme − or equivalent − in which certain events (where one or more QAR parameters are outside normal limits) automatically trigger a report, and the crew concerned are contacted confidentially by the SESMA representative; the “Pitch” auto-call would undoubtedly result in you hearing from him or her in a week or two. He/she would be at your disposal to discuss the flight-recorder traces. Later, the event would be added to a database to analyse possible trends in pilot handling on your fleet. If it was considered sufficiently important as an example, a summary would be published in-house, again with the flight date and crew names omitted.

You say the “controls were sluggish”, but you are unable to say if the IAS was above or below VLS. The “Pitch” call suggests that, having started the flare late, you over-flared. In that case, it was not the CONTROLS that were sluggish, but the wing itself, which was unable to generate enough lift to arrest the ROD in the short time you seem to have given it. This may have been partly due to a lack of airspeed.

But closing the throttles would also have robbed you of a useful vertical component of thrust (as well as putting you in a position where a go-around from a severe bounce would have been hampered by a lack of thrust for several seconds, at least).

You write: “I feel g load could have been lesser if I had relaxed the pitch up demand, after finding no response intially. I dug the main wheels with constant demand.”

Yes, definitely you should have relaxed it. It seems you were already at a pitch attitude higher than desirable if you had been initiating a go-around from a rejected landing. I don’t have that procedure to hand, but recommend you look for it in your FCOM or, if necessary, elsewhere.

In answer to your other question, “what could have been done to reduce the g load on touchdown”, it is also true that − if the nose is high − a small, brief, forward movement of the stick, just before main-wheels touchdown, can reduce their impact. But it is vital not to overdo it, and the pitch-down rate must be arrested with some back-stick as soon as the main-wheels touch down, to stop the nose-wheels thumping down. This is not a technique, however, that I would recommend to anyone in your scenario.

To summarise.
If you don’t like the look of it at any stage, go around. :ok: (Be prepared for possible main-wheels contact with the runway.)
But once the throttles have been closed, this may not be possible.
So never close the throttles until a safe landing is assured.

Get as much value as you can from this experience.

Chris

Hello IFLY INDIGO,

First of all, congratulations to you for sharing your experience with us and for seeking advice.

I would like to question many major airlines' policy about auto thrust use. (and Airbus' recommendations about A/T use)

I fly A320 in a company where manual flight skills are still intensively trained and encouraged by the training department and I am very glad about that. The large majority of the landings in our company are -conditions permitting- done with F/D, A/T and AP off!

So our company is really not concerned by what Airbus captain Jacques Drappier has to say about manual flight skills. (Jacques Drappier, like myself, is a former SABENA-pilot BTW) Read also this thread: Pilot handling skills under threat, says Airbus

In my company all pilots will fly the approach to Funchal, Madeira with A/T off, while most other companies forbid their pilots to disconnect A/T over there.

All pilots in my company will agree that we, as pilots, can do a better job then the A320 autothrust system. It's my experience that if you fly the A320 by hand but with A/T engaged in stormy and gusty conditions, the A/T is a very foolish "speedchasing device". For instance: when you're a little low, but a litlle high on speed -due to shifting winds for instance- the A/T will reduce thrust too much and not anticipate fast enough to stop you from getting in a nose high, low speed condition when you pull the sidestick to recover from your low trajectory. It appears to me that that is what happened to you during your flare.

Of course, "giving a handful of thrust" is not easy in the Airbus when your thrust levers are immobile in the CLB detent and you are "at the mercy" of the A/T system! In manual thrust it's a piece of cake!

Now I'm getting ready to be flamed about the fact that I dare to go against Airbus' recommendations about A/T use, but really guys, it's time that pilots relearn how to handfly an airliner, especially Airbii! Make life easier on yourself by using the AP and AT when there's a good reason to do so but make sure you keep your basic skills in good shape!!

Best regards,
sabenaboy

IFLY INDIGO, thanks for sharing. Can you tell us more about the wx conditions ie the pressure altitude and temperature?
As the ldw is below max the other things that could be significant in this situation is ref to Vls, field temperature and alt density. (aircraft will react differently at 7000 asl and +35C then at sl 15C)

can't agree more. I like the Boeing moving thrust levers much better. Need more thrust? Just move it up a little then release the pressure. Makes it more instinctive.

Flame incoming.

if winds dying down,either delay the thrst reduction to idle or goround without any hesitation