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-   -   EK A330 Heavy Landing at BHX (https://www.pprune.org/rumours-news/315673-ek-a330-heavy-landing-bhx.html)

BHX86 27th Feb 2008 18:57

EK A330 Heavy Landing at BHX
 
Anybody have any news on this. It happened last night.

BHX86 27th Feb 2008 19:22

lol. No it wasn't.

S78 28th Feb 2008 07:16

Came in on EK37

The a/c is currently grounded with damage to the undercarriage, FDRs have been removed so they can have a look at what happened.


No further details at the mo.


S78

Bearcat 28th Feb 2008 07:22

BHX can be a tricky place at the best of times esp in windy weather but weather was fine y'day. Must have been some arrival.

Doors to Automatic 28th Feb 2008 08:30

I have watched many a 777-300 land there - it is very tight!

tubby linton 28th Feb 2008 08:33

I have always found the A330 to be very good at stopping unlike an A321.I would suggest that this incident will be traced back to the lack of response from the athr late in the approach.I have seen it do this myself and it is especially marked on almost calm days.I believe a UK operator had a similar incident last year.

tiggerific_69 28th Feb 2008 10:55

Saw the aircraft depart BHX at approx 10.30 this morning.

jshg 28th Feb 2008 11:20

I know nothing of this incident, but I do fly the 330.
For reasons known only to Airbus, below 400 ft radio height the autothrust logic changes. Thrust response 'relaxes', rather than trying to chase the speed. Any small increase - or decrease, crucially - in IAS does not provoke a change in thrust.
If speed falls a long way, there is a thrust response. But thrust levels on the 330 on approach are very low anyway as it's all wing. Furthermore, the three-spool engine configuration means thrust builds quite slowly.
The net result is that below 400 ft, by the time the autothrust responds the speed can be very low - I've seen 12 kts low - and whilst N1 is increasing, there is little increase in thrust.
This normally becomes a problem in light winds, particularly with gentle tailwinds on approach.

BitMoreRightRudder 28th Feb 2008 13:09

jshg

Is the autothrust logic you mention specific to the 330? 12kts underspeed sounds interesting!

jshg 28th Feb 2008 14:44

It's an "improvement" from the 320/321 design, which fortunately doesn't have it. I'm not sure about the 340.

misd-agin 28th Feb 2008 14:57

So if the a/t's are slow to respond to necessary power changes who's responsible to get the appropriate power from the engines?

Gretchenfrage 28th Feb 2008 15:48

Maybe someday the Airbus-Neverland will admit that the fixed throttle was not that good an idea.
It confused more than one crew and has never proved any advantage over the moving cousin.
How i liked the good old wrist-shot on short final .....

Ladusvala 28th Feb 2008 16:21

Isnīt it possible to manually add a bit of thrust if the autothrottle doesnīt do it, or is it inhibited?

(I have not yet flown an Airbus.)

TCX69 28th Feb 2008 16:33

Apparently the a/c was coming in way too fast and damaged a part of the landing gear hence why it was AOG for a while. A part had to be sent in From Airbus so that it could be fixed.

PositiveRate876 28th Feb 2008 16:42


The net result is that below 400 ft, by the time the autothrust responds the speed can be very low - I've seen 12 kts low - and whilst N1 is increasing, there is little increase in thrust.
So you've actually watched it get 12 knots below Vapp on final below 400ft! :eek:

Why bother keep your hand on the TLs then? :confused:

Mr @ Spotty M 28th Feb 2008 17:10

That's funny as far as l know, no damage found on inspection.
FDR had been removed and to sent to main base and a/c given a one off to fly Nil pax back to base.
What happens next is what figures are on the FDR readout, could end up with a gear change.

Flap 5 28th Feb 2008 17:42

For those who have not flown the Airbus or who have the Boeing fanboy bias against them: The thrust levers are in the climb detent with the auto thrust active from thrust reduction after takeoff to retarding the levers on landing. If you want more thrust you only have to move the thrust levers forward out of the climb detent. Then the thrust goes to the thrust lever angle (TLA) setting.

This however can cause a rapid increase in thrust and with the power available in A330 engines can lead to embarrassment on short finals and a go around. However you do have manual control over the thrust.

Similarly thrust lever retarding below the climb detent will provide a maximum thrust through the auto thrust limited by the TLA position manually selected.

Or you can cancel the auto thrust completely and control the thrust manually through the thrust levers.

Now what was the problem?

Gretchenfrage 28th Feb 2008 17:48

Flappy

Yes, you can do that, but you proved my point very nicely by stating that the thrust in doing so might be too much, at least not what you wanted. You won't have that effect on a Boeing ..... you will get exactly what you push for.
Another little inconvenient: Try doing your little trick below 100 feet, and that's where most of us would be likely to do it to save the landing, and with the fantastic AB logic ..... you end up with GA thrust!!!! Definitely not what you intended methinks.
Finally, if you do the approaches with manual thrust to avoid such landings, whats the point of having the AutoThrust in the first place? On Boeings you don't disconnect it, it helps you and you can help him, on AB's it's either one or the other.
If you take away the AB or B glasses, any logical thinking pilot would have to admit that the B system is more flexibel, to use a less provocative term.
but that's just my view of the things.

Reimers 28th Feb 2008 17:56

Fortunately the company I work for still allows the use of manual thrust whenever the pilot wants to use it (not during CAT III or such, though).
We routinely fly manually and when AP off, the A/THR shall also be disengaged.
The A/THR has its flaws, none of which can be done away with by thrust levers moving back and forth, or else it will no longer be an Airbus.

Flap 5 28th Feb 2008 18:25

Gretch,

In fact on the 737 you do disconnect the auto thrust on the approach. Not doing so will result in the auto thrust chasing the speed with consequent porpoising.

You can leave the A/THR enagaged on the airbus because in normal law the nose will remain pointing down the glideslope regardless of any increase or decrease in thrust.

The 777, being fly by wire, also allows the A/THR to remain engaged, but it certainly insn't the case with the 737.


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