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A320 how to save this landing

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A320 how to save this landing

Old 6th May 2010, 14:50
  #41 (permalink)  
 
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I fly a 21st Century Designed mid sized chunky bizjet with airliner derived avionics. It does not however have autothrottle.

I was taught to have a hand on the TL's within 1000ft of the ground just in case, forgive me but it just appears to reinforce the lack of basic airmanship and stick and throttle skills that seems to be apparent on these types.

Too much reliance on automatics in an ever changing weather environment with too many variables with a A/T system that by everybodys reckoning isn't able to cope.

Training and basic airmanship issue imho ......a small addition of power and its prompt removal would have made all the difference here - why didn't it happen?
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Old 6th May 2010, 15:13
  #42 (permalink)  
 
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Hi,

a small addition of power and its prompt removal would have made all the difference here - why didn't it happen?
There seems to be a common agreement that a quick burst of power would have made all the difference.

But how much extra flying speed might you expect to gain from a quick burst? 5kts or so? I don't think 5 kts would make a significant difference to the total lift available from the wing. A pitch change makes a bigger difference.

If I was flying a conventional aircraft, then the burst of power would help raise the nose, and the extra 5 kts would make the aircraft feel lighter in pitch. Unfortunately when Bernard Ziegler designed the A320, he didn't put the aircraft into Direct Law during landing, so we are stuck with the feel it has with a reference pitch attitude remembered at 50 feet.
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Old 6th May 2010, 18:02
  #43 (permalink)  
 
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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.
I have flown the Airbus for 10 years and 737 before that and I quite agree with you. Love the aircraft in general but the autothrust system was wrong from inception.
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Old 6th May 2010, 21:58
  #44 (permalink)  
 
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But how much extra flying speed might you expect to gain from a quick burst? 5kts or so? I don't think 5 kts would make a significant difference to the total lift available from the wing. A pitch change makes a bigger difference.

If I was flying a conventional aircraft, then the burst of power would help raise the nose, and the extra 5 kts would make the aircraft feel lighter in pitch. Unfortunately when Bernard Ziegler designed the A320, he didn't put the aircraft into Direct Law during landing, so we are stuck with the feel it has with a reference pitch attitude remembered at 50 feet.
Nobody mentioned 5 knots, try not to quantify this - this is part of the problem. Basic Airmanship taught to people in Cessna 152's the world over, sense the sink add power and pitch, reduce the rate of descent. As opposed to blind faith that automatics will sort out all enviromental occurences.

I remember being parked on RS1 at Heathrow very early one morning when an A340 came into land it was very gusty and the aircraft was flown onto the ground with lots of additional power on a number of occasions at very low level. I remember thinking that a lovely approach could be flown under difficult conditions especially having "been on the road" for possibly 12 hours + (inc crew rest etc etc)
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Old 7th May 2010, 00:20
  #45 (permalink)  
 
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The previous C 152 post was right on. If you can't fly a C152 you will be very dangerous in an airbus because you will let it do things you wouldn't do. After thousands of landings with a handful of go arounds, only one in an airliner, except for minimums approaches with no lights at DH using proper power and pitch entering a flair is not difficult even with windshear below 50 ft. Nobody should be flying an Airbus or any large aircraft if they have a problem with a C152.
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Old 7th May 2010, 01:29
  #46 (permalink)  
Beau_Peep
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Hi Chris & other fellows,

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.


I didn't start the flare late. due to sudden drop at 50ft, the center point of this thread, any flare would be called late eventually.

I agree a little bit of derotation could have reduced the impact.

When I said controls were sluggish, I meant the control input didn't give me required increase in the lift.

It was a stabilised approach with steady 8 kts tailwind upto 50ft.

I don't agree with the suggestion Moving thrust lever out of CLB detent a bit in this case. first it is too much of addition of thrust. And moving the levers through the detents, while adding thrust or reducing thrust, has its own precious time element. Detent resists the movement. As I told you all in the very beginning, reaction time was very little, due to sudden sink. So I think it would not have saved this landing.

I totally agree the use of manual thrust is a far better option then relying on ATHR. But such decision is to be taken well before stabilisation altitude, not at 50ft ! I started this thread not to debate manual thrust VS ATHR. My intention was to discuss the possibilities of 'how to save this landing' IN THIS PARTICULAR SITUATION.






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Old 7th May 2010, 01:42
  #47 (permalink)  
Beau_Peep
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PA was 3100ft , OAT 34deg C
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Old 7th May 2010, 02:05
  #48 (permalink)  
 
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PT6A

If the situation is thus in India, they are in for a very hard and unsafe time. It is F/O experience that builds Captains. Not giving 50% of the landings to F/Os is simply criminal.

GF
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Old 7th May 2010, 06:54
  #49 (permalink)  
 
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GF,

It sure is... It is a DGCA rule.. I have the list for Indigo and the amount of Captains who are allowed to even allow FO's to land is very very few.

I know some F/O have to go to the sim in India because they dont have legal landing currency as they get to do so few.

PT6A
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Old 7th May 2010, 06:57
  #50 (permalink)  
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IFLY

I am assuming that you were at VOBL RW27 approach?

How do you know it was 1.76 g landing? If you are getting your number from the load report, you may want to call either safety department or the FDR monitoring team and get the actual numbers. I've had smoothest of landings and the load report was 1.65 and had a very firm landing and load report was only 1.2. So it all depends on what you were doing one second before touch down.

Were you performing Config 3 landing? Not that it is going to make a difference but lack of drag could have saved you but than again you are a lot closer to tail strike as you approach with higher pitch attitude.

On the approach I always check the VLS calculated by FMGS and FAC (on the PFD). I make sure that the difference is minimum and that the FAC calculated VLS is not higher than FMGS. I have seen it in the past that the actual VLS (on PFD) was only 1 knot below Vapp and that calls for some interesting landing.

Like the others have said it earlier, I'd have increased the pitch, reduce the rod and hold it there until thrust starts spooling up, if you were in BLR runway length is not a problem. I know the reaction time is less, but if you do not go around, this would be your next best option. Have you ever landed with thrust? May be next time you fly with a TRI/TRE ask them if you could practice it, it will give you more insight on how aircraft reacts.

For hard landings, the bus will print the load report if it was above the parameters, you may have to check it with your engineering department since the report printing is inhibited in IndiGo aircrafts.

Last edited by DesiPilot; 7th May 2010 at 07:16.
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Old 7th May 2010, 07:06
  #51 (permalink)  
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PT6A

You are rght about the DGCA regulation. The regs says that the first officer need a minimum of 50 hours on type a sim check and to fly with a captain who is cleared for assisted take off and landing before they are allowed to t/o and land. For captains, if it is their first command they require 1000 hours on type.

When I joined airlines in India I had close to 4000 tt, previous experience of flying CRJ but I was not allowed to land A320 until I completed 300 hours on type. In 2006-7 requirement was 300 hours on type which is reduced to 50 now. Typical dgca
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Old 7th May 2010, 07:16
  #52 (permalink)  

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Originally Posted by IFLY_INDIGO View Post
OAT 34deg C
Here's my suspect to why it happen. Not loss of tailwind (momentary IAS increase), but perhaps entry to overheated layer of air over threshold? Madrid (elev 2000) 33R (displaced thr) produces some quite interesting sinkers on a sunny day. Change in density would reduce lift available in line with Chris Scott's comment.


Sincerely,
FD (the un-real)
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Old 7th May 2010, 07:39
  #53 (permalink)  
 
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Originally Posted by IFLY_INDIGO
My intention was to discuss the possibilities of 'how to save this landing' IN THIS PARTICULAR SITUATION.
Well, perhaps it wasn't "saveable". Of course reverting to manual thrust at 50' is not option and I think that perhaps a Go-around was the only possibilty to avoid a firm landing. But then again: who cares about firm landings? It's not because it's firm that it's not a good landing! (Despite what most pax will be thinking )

So my advice would be not to use A/T for landing unless it's necessary (or unless your company says you HAVE to use A/T all the time. ) To me "necessary" means that I use A/T for autolands only or every once in a while for training. (After all I still want to be able to use all the automatic gizmo's ) I personally NEVER use A/T for landings in gusty or stormy conditions.

Have fun and safe flights,
Sabenaboy
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Old 7th May 2010, 08:42
  #54 (permalink)  
 
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Now, I'm not a driver (I hope to be, one day in the distant future ) but I have studied fluid dynamics and I also have an intense interest in the flight controls and laws of all Airbus FBW.


With reference to:

When I said controls were sluggish, I meant the control input didn't give me required increase in the lift.
Do you mean the ROD did not reduce commensurate with what you would expect during the flare, or what you would expect during final approach? Remember, when the aircraft is in Flare mode, at 30' RA the reference attitude is 'washed out' over 8 seconds (Which, I assume means that a nose down trend is introduced) to ensure the PF progressively flares the aircraft. Now, would I be correct in assuming, at this point the control input required to reduce the ROD will be greater than that required during the other flight regimes (Climb/Cruise/Descent/Approach)?

However, if that has been taken into account, and you are very sure you didn't flare late then I would tend to agree with FlightDetent about a low density, high temperature pocket at the threshold. Might seem a real silly question, but are there any watercourses or streams just before the threshold? High localised humidity would decrease the density even further.

Just $0.02.

Tom
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Old 7th May 2010, 12:02
  #55 (permalink)  
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What was the wind given by the Tower?
 
Old 7th May 2010, 15:08
  #56 (permalink)  
 
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I don't agree with the suggestion Moving thrust lever out of CLB detent a bit in this case. first it is too much of addition of thrust. And moving the levers through the detents, while adding thrust or reducing thrust, has its own precious time element. Detent resists the movement. As I told you all in the very beginning, reaction time was very little, due to sudden sink. So I think it would not have saved this landing.
You're suggesting that you dont think adding power on short finals as required to avoid a heay landing (and if that wasn't going to work a G/A) is a good idea. Forgive me if Im putting words into your mouth or twisting the words that came out.

I dont care whether its a 152/787/320 its up to you to putting the aircraft where you want it at all times using all the assets you have, if you disregard the thrust this is going to happen again. Use whatever power is required to arrest the ROD and fly level if required if you have any doubt that you wont make it in go around. In the landing config there should be enough thrust available to arrest the rate of descent thats a certification issue.

I'm not suggesting you practice on revenue flights but Level D sims do a crap job of accurately recreating close to the ground events, maybe ask your skipper if you can do a non A/T approach next time the weathers good
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Old 7th May 2010, 16:25
  #57 (permalink)  
 
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Originally Posted by G-SPOTs Lost
You're suggesting that you dont think adding power on short finals as required to avoid a heay landing (and if that wasn't going to work a G/A) is a good idea. Forgive me if Im putting words into your mouth or twisting the words that came out.
G_SPOT,

Looking at your profile, I assume that you're not familiar with the Airbus A/T system. Unlike in Boeing the thrust levers in an Airbus stay immobile in the CL(im)B detent the whole time until they are retarded during the flare. The A/T system will then adjust thrust as necessary between idle pwr and climb thrust. (I like my airbus very much and got used to this design, but I have to admit Boeing's system with moving levers is a better design.)

What IFLY_INDIGO was probably trying to say is that at 50' it's not easy -nor is there time- to first adjust the thrust levers in the necessary position and then push the A/T disconnect button on the thrust levers.

That's just one of the reasons why I hardly ever keep A/T on for landing in my 320.

Regards,
Sabenaboy
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Old 7th May 2010, 18:05
  #58 (permalink)  
Beau_Peep
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perhaps entry to overheated layer of air over threshold? Madrid (elev 2000) 33R (displaced thr) produces some quite interesting sinkers on a sunny day. Change in density would reduce lift available
this sounds plausible. it felt as if all lift was gone at that moment and we were a dead stone falling free.. and if that is the case, I feel even a go around would not have prevented the hard touchdown before lifting off again..
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Old 7th May 2010, 23:27
  #59 (permalink)  
 
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'Morning, IFLY_INDIGO,

I see I was wrong to infer that you started the flare late - sorry. Hope you take my point, however, that - in a nose-high attitude - any engine thrust is contributing to lift.

The problem we all have in this discussion is that we will never know what happened to the IAS in the last 100 ft of your approach. That's why it's such a pity that your airline does not seem to monitor QAR-recorded 'events' as I described in my previous post.

Despite that, it's been an interesting and valuable exchange of views, and I agree with much that has been said. Very glad to see that so many younger guys agree with my preference for using manual thrust for manual landings, PROVIDED you are visual fairly early, so you can disengage the A/THR in a smooth and leisurely fashion. (We lost the battle against non-driven thrust levers in 1986, I'm afraid...)

Happy future landings!

Chris
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Old 8th May 2010, 00:36
  #60 (permalink)  
 
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All aircraft, no matter who made them, needs a pilot to fly them. They may or may not have experience in this plane but they can fly it. They all fly basically the same so the throttle hand and the yoke hand should be coordinated by now. If you are flying any aircraft you should be able to do a 3 degree approach and land without a lot of procedures. Just learn how to fly any airplane and use basic pilotage and forget about the special Airbus procedures. A lot of Boeing guys actually transitioned to Airbus and did ok with Boeing procedures. As I said before if you let automation cause an incident you lose credibility as a pilot.
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