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-   -   A330 hard landing in September (https://www.pprune.org/rumours-news/353219-a330-hard-landing-september.html)

pilothouse 2nd Dec 2008 08:51

A330 hard landing in September
 
This week's Flight International (2-8 Dec, page 9) tells of an unidentified A330 that suffered a hard landing. The report tells of a "severe" impact that required replacement of the main gear.

Apparently, the elevators failed to respond to the flare input from the sidestick, because one of the three computers fitted was of an inappropriate model.

I don't remember reading anything about this at the time. Can anyone tell us anything more, like which unfortunate operator was involved? And whose maintenance facility fitted the computer that should not have been there.

Taking into account the Qantas A330 incident, twice within a few weeks pilots have hauled on an Airbus sidestick and failed to get the required result.

rogerg 2nd Dec 2008 09:04

Incorrect procedures. Same thing has happened when elevator or aileron cables are connectected backwards. Most aircraft are fly by some sort of wire.

Jofm5 2nd Dec 2008 10:28

Sounds like this one...
 
TAM Linhas Aereas was the operator and NY JFK was the airport.

Report on aviation herald here The Aviation Herald

The accident, although not covered by both NTSB and FAA databases (standing of Dec 1st 2008), triggered a Safety Bulletin 2008-86 by European EASA which reported, that the elevators remained in neutral position for several seconds although the pilot had commanded a pitch up via the side stick. This resulted in a hard landing and subsequent replacement of main landing gear. The troubleshooting found, that the flight control primary computer #2 did not match the primary computers #1 and #3, so that #2 sent erroneous commands to the elevator servo controls leading to force fighting between the actuators and unwanted elevator movement. EASA stressed, that it was the uncertified mix of flight control primary computers leading to the accident and reminds all operators to make sure, that operators should adhere to interoperability and mixability rules to establish a certified aircraft configuration. The full Safety Bulletin is available at: http://ad.easa.eu.int/blob/200886_Airbus_A330_A340_Uncertified_Configuration.pdf/SIB_2008-86_1

hamil 2nd Dec 2008 13:25

Manual landing during a cat II approach is permitted but several airlines don’t recommend it for their operations and I don't know if TAM belongs to that group. Anyway, why would a pilot decide to disengage A/Ps to check his/her habilities after a night long haul flight and with poor weather at destination to perform a manual operation with a huge chance of making a hard landing (even on an airplane without any previous tech report)?

Samba Anaconda 3rd Dec 2008 21:35

Hard landings on A330
 
Years ago in another life with a South East Asian air carrier, I was an eff oh on an A330 landing in DEL. It was a hot gusty afternoon and being new, I was fighting the ever changing pitch and roll movements with the sidestick.......the skipper told me to " go easy ", easier said than done! At flare altitude, with side stick flare input, nothing happened and we were still sinking like a rock. Now more sidestick pitch command to full up with nary a decrease in rate of sink! The skipper slammed the thrust levers to TOGA and away we went for a wave off........even then we touched the runway fairly hard as he took over control. He took us around for another approach with a fairly decent landing.

He then explained to me what he called " scarebus or screwbus traps "....if one fights the updrafts and abrupt pitch ups on short finals close to 100 ft RA with full side stick down inputs, the THS will trim down and when the ' flare law ' ( the THS stops trimming ) engages below 100 ft RA, there may be insufficient pitch up authority left to flare sufficiently.

It has not happened again later in my short time on the A330, but I wonder if anybody else ever experienced such lack of pitch authority on landing!

Cavallier 3rd Dec 2008 21:41

Can I ask why you would want to be making FULL DOWN inputs on the sidestick at 100 RA ???

The Cav

Carnage Matey! 3rd Dec 2008 21:48

Isn't that called overcontrolling?:hmm:

PJ2 4th Dec 2008 02:58

CM;


Isn't that called overcontrolling?
Absolutely is.

FWIW, I took a look in our data program at some flights in gusty conditions to see what the ailerons and elevators were doing in autoflight, and then watched them when the a/p was disconnected.

The traces were relatively smooth up until the disconnect. After the disconnect, the stick trace routinely showed very large corrections with consequent "following" of the ailerons/elevators as they kept up with both the gusty conditions and the sidestick requests of the flying pilot. The traces were quite "spikey", not smooth and of greater amplitude. While there was nothing at all unsafe about it, it illustrated precisely what you point out..over-controlling. I suspect it happens a lot and I would point to training and understanding what FBW really is, even when the a/p is disconnected. Leave it alone, make tiny corrections and if a large one is needed, make it, then leave it alone rather than chasing the attitude - a lot of PIO results and it's a bouncy ride for the passengers to boot.

We have an event which monitors "stirring the pot". We very often see full stick deflections in roll and not always in gusty crosswind conditions. We don't see full up/full down deflections very often but it does occur. Such deflections close to the ground are very bad news indeed. We also monitor dual inputs and see them not infrequently, another serious no-no.

Anybody know what the 'g' was for this landing? I'd like to know if it was over 2.6g's, or if the descent rate was > 360fpm.

Molokai 4th Dec 2008 08:49

Give the anaconda a break........you guys must be born with a sidestick in your mouth! Didn't he say he was newbie f/o struggling on hot and gusty day. Such things happen. Good on his skipper to save the day.

Carnage Matey! 4th Dec 2008 10:17

No criticism meant of Ananconda but what was his training department doing explaining the phenomena as an Airbus problem? The idea that full nose down side stick inputs close to 100RA might be acceptable is bizarre. No wonder they got some firm arrivals!

Mat Tongkang 5th Dec 2008 00:27

Anaconda might have been guilty of overcontrolling but at no time did he say that he had full sidestick pitch down!

Also he related that his skipper explained that " if one fights...............". Well that was just supposition and postulation.......hardly cause for some "bizarre" conclusions and comments above.

Sitting Bull 7th Dec 2008 14:18

Having flown thousands of hours in the A330/A340 and also on the B744/B777, I think I´m able to make an unbiased statement regarding manual control during landings in gusty winds, in sidestick-and non-sidestick a/c:

the airbuses are much more precise machines, yet they require quite precise handling by the pilot, meaning don´t make large control inputs unless they are REALLY needed (let the computers fight the gusts)

the boeings are way behind in precision (also the B777), yet they take more abuse on the controls by the pilots, which makes them easier to handle in gusty winds on landing.

CONF iture 7th Dec 2008 14:42

Interesting comment Sitting Bull.
Question : Is it also an automatic trim in manual flight on the 777 ?

sleeper 7th Dec 2008 16:35

B777 is auto trimmed on airspeed in manual flight. So any increase or decrease in speed must be trimmed manually. This means that you can feel the aircraft while being fly by wire.

FlexibleResponse 8th Dec 2008 13:16

In the Airbus, you move the stick as much as you need to control the flight path...

...rather much the same as in any other aircraft...

Jet_A_Knight 9th Dec 2008 01:19

Someone please tell me if the inputs shown here are 'reasonable'.

YouTube - Landing A320 Hard Crosswind ( Sidestick View )

I've never done that or seen anybody else do so.

beardy 9th Dec 2008 07:24

It all looks very unreasonable to me, but I wasn't there. No input (demanding a rate of movement) is held for long enough to produce any significant angular movement of the aircraft. Moreover, if he had held the stick further up he would have had greater control of it's displacement from neutral.

pilothouse 9th Dec 2008 07:51

That Youtube is fascinating - confirms my view that A320 ailerons are too small and that you often need full sidestick deflection in a bumpy crosswind. In fact I once had the stick hard over and still the aircraft rolled the wrong way - not nice at 20ft.

Wear the Fox Hat 9th Dec 2008 09:17


In fact I once had the stick hard over and still the aircraft rolled the wrong way - not nice at 20ft.
Anybody passing "Lakers Revenge" at 50ft into 26L at Gatwick in a strong southerly will testify to this :}

TheKabaka 9th Dec 2008 09:48


confirms my view that A320 ailerons are too small and that you often need full sidestick deflection in a bumpy crosswind
Not true in my opinion. Full sidestick deflection means max roll rate demand (15 deg/sec from memory) not max aileron deflection


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