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IFLY_INDIGO
1st Mar 2008, 03:26
Hi there,

In my view, the most dangerous thing about airbus family (fly-by-wire ones) is "taking over the controls closer to ground"... it is a tough art.. suppose your first officer is PF and during takeoff, he rotates early and fast increasing the chances of a tail strike.. now you have to takeover the control and if you don't press the red button first, you will screw it up further... similarly while landing, if the fellow does not flare or pulls the stick back too much, would the capt be able to press the red button in a fraction of a second and control.. I think it would be art to master...


cheers...

Clandestino
1st Mar 2008, 07:38
if you don't press the red button first, you will screw it up further

I agree... oh, wait a minute! Why would anyone want to take over without pressing the take over pb?

Taking over the control is always a risky procedure. It is even riskier when done close to the ground. And risk gets fairly unacceptable when it's not done properly. Proper procedure for FBW Airbi is to press 'zee red button' and then do whatever you want to do. Not pressing it is not an option. This procedure is not intuitive for pilots coming from classic types and it has to be well taught and ocasionally rehearsed (in sim, of course).

Your A320 is not 737, it's not MD80 and it's definitively not Tu-154. Don't fly it as if it were on of these, fly it in the way your FCOM tells you to.

javelin
1st Mar 2008, 09:07
Give Mr Indigo a break, I knew exactly what he meant.

It is quite correct that the last few feet with a very inexperienced F/O (Cadet ?) can be challenging........ That is how one of ours got damaged last year and needed many, many thousands of dollars work back at Toulouse :sad:

It is about time that the operators realise that ZFTT or bringing Cadets straight through onto the jet may not be the way forward and a year or more on turboprops like most of us did pays huge dividends.

westinghouse
1st Mar 2008, 09:31
hi,

if the guy happens to rotate too much all you have to do is push your stick a bit forward.
of course the dual input sound would come up but airbus combines both stick inputs and comes out with one.
similarly it can alsio be done for landing.
at a critcal time when your close to the ground this would be very much helpfull.

bye

TolTol
1st Mar 2008, 10:11
What happens when the guy in the left seat pulls back too much on take off? Or screws up the flare?

CY333
1st Mar 2008, 10:58
A dual input will not give a double amount of output as a guy was telling me once.
Actually what it will do it will increase the rate of the movement.
For example it will increase the rate of roll but not the amount.

Chris Scott
1st Mar 2008, 11:08
Quote from TolTol:
What happens when the guy in the left seat pulls back too much on take off? Or screws up the flare?


Presume the above question is "tongue-in-cheek"? But just in case it confuses anyone, it makes no difference which pilot is mis-handling his/her stick.

I agree with westinghouse. In the case of dangerous over-rotation, I see no reason why a brief application of forward stick by the other pilot could not be used. The trouble with Clandestino's policy ("not pressing it is not an option") is that, by pressing the button, there is a risk of over-controlling the stick at the moment you take over. IFLY_INDIGO has raised an interesting point.

But I have not flown A320 for 6 years. You should discuss all this with an [U]experienced A320 base-training captain, as well as seeing what Airbus and your companies say in your Flight Training Manuals.

IFixPlanes
1st Mar 2008, 16:14
...A dual input will not give a double amount of output as a guy was telling me once.
Actually what it will do it will increase the rate of the movement.
For example it will increase the rate of roll but not the amount.

Sorry, but not correct.

The AMM (Aircraft Maintenance Manual) says:
...The CAPT and F/O stick orders are algebraically added...

PA38-Pilot
1st Mar 2008, 18:16
I have to disagree. The most dangerous thing about an airbus is a pilot who has not been trained well...

Besides, at least in conventional aircraft, you would need to fight against the other pilot's inputs to take over. It is a lot easier on the A family.

celtic mech
1st Mar 2008, 20:01
"Sorry, but not correct.

The AMM (Aircraft Maintenance Manual) says:
...The CAPT and F/O stick orders are algebraically added..."

Agreed with totally! The output is always the algebraic sum of both sidesticks....e.g. Capt inputs 12 degrees left turn and F/o inputs 6degrees left turn....because they are both in same direction, the result is a 18degree left turn.
Likewise a 10degree input to one sidestick with a 10degree input to the other sidestick in the opposite direction cancel each other out.

Milt
1st Mar 2008, 20:44
Looks like Airbus and their TPs have come up with a compromise with their dual side stick controllers which has some unsatisfactory results during impromptu changes of command.

Until there is a better system there should be more emphasis in the simulators on this aspect so captains become intuitive and know what to expect in unusual circumstances particularly at critical stages of flight.

Is there a way other than this thread for those who have problems to arrange constructive feed back which will reach Airbus and the Regulatory Authorities.?

Once took over control from a beginner in the right seat of a C47/DC3 who had wound in a lot of left aileron against the auto pilot. I reacted with an equal amout of right aileron and the aircraft flew gaily straight and level. Diconnected the A/P and we each wound in full opposite aileron against each other with no reaction from the Gooney. I made a very careful straight in approach to land ASAP and declared that something was very wrong with that one. But the next one was just the same. They all did it because there was enough stretch in the correctly rigged control wires. Now I wonder why I didn't try the same thing in pitch. So - it is not a new problem for FBW and dual side sticks.

IFLY_INDIGO
2nd Mar 2008, 02:52
Westinghouse, your solution sounds good, but "DUAL INPUT" call can further confuse the novice F/Os and aggravate the situation... As I a Capt, If I notice some problem with F/O in flying closer to ground, I would prefer to deactivate his sidestick first before giving input...

TolTol, I am sorry, If my thread has offended you... you are right any pilot can screw up thing... but chances in the case of capts screwing up are lesser because of greater experience... thats the reason they are capts at the first place... and when a capt gives flying to F/O, his licence is always on stake, not the other way round...

My concern is about the instantaneous reaction of human beings... or rather about doing things in the correct order... pressing red button, hold it down, and give corrective input... all to be done in a fraction of a second..

cheers...

Bruce Waddington
2nd Mar 2008, 03:48
All,

Chris suggests that, " You should discuss all this with an experienced A320 base-training captain, as well as seeing what Airbus and your companies say in your Flight Training Manuals."

Very good advice!

And the answer is, from all three sources ... Say clearly "I have control", Push and hold the the Red Button, apply input as required.

The problem with putting in a brief input of any kind without the above procedure is that the pilot flying may choose that same moment to reverse the input that has so alarmed you, and now you are both pushing, pulling or whatever. Oops !!

When completeing Initial Operating Experience Training with new Captains, or Captains new to the Airbus, part of the discussion always revolved around this sort of situation. My advice was always the same ... If you are going to intervene do it early and do it in accordance with the above procedure. And never be afraid to tell the pilot flying to go-around if you do not like what is happening.

best regards,

Bruce Waddington

ACMS
2nd Mar 2008, 05:54
The most dangerous thing about the A320?

It's an Airbus.:rolleyes:

electricdeathjet
2nd Mar 2008, 07:11
Acms

You Are So Funny :}

Farrell
2nd Mar 2008, 08:43
Would a simple "I have control" not be better?

After all, if the FO is low hours, he probably still has the muscle memory from that command still fresh in his head.

Wingswinger
2nd Mar 2008, 08:45
yep, FO's have muscle between their ears. :E