A Couple Of Airbus Questions

[topgundom]

Could anyone please put me right on a couple of airbus technical points. (I refer mainly to the A320 but I suppose it's similar on most of their aircraft.)

1: You know the thrust levers are gated, well how do you taxi?
Can you nudge them forward slightly without clicking into the CLIMB gate or do you taxi on idle?

2: Is there a philosophy concerning the push/pull dialls on the FCU? I mean, for example, what's the difference between pushing the alt control or pulling it?

Thanks.:ok:

[square leg]

I don't fly A320 (yet), but to taxi, simply push thrust levers slightly forward like on any jet.

When pulling a knob (like HDG for e.g.) you select it. When pushing it, you have the FMC manage your lateral mode (i.e. LNAV or whatever other mode there is).

I'm not in the know, thus I speak under correction.

[topgundom]

Nice one Square Leg,

I thought it was something like that.

Cheers.

:cool:

[Dream Land]

1. Thrurst levers move freely from thrust idle up to CLB power, shortly after there is a detent called FLX / MCT, just forward of that is TOGA. Toga stands for take off / go around thrust, FLX is for a reduced thrust takeoff, the same detent serves for MCT which would be the position for single engine maximum continuous power. Remember the thrust levers moved into one of these detents just acts similar to selecting a switch, telling the FADEC what you are requesting.

2. Simplified, the FCU philosophy with the exception of the BARO knob is push for managed, pull for selected, i.e. changing the speed while enroute: pull the speed knob and reduce or increase selected speed as necessary, to return to managed speed, simply push the speed knob, speed will now return to managed speed, based on the current cost index selected.

Hope this answers your question.

D L:ok:

[TopBunk]

Dream land
Thrurst levers now that sounds like something Barry White (RIP) would have had!:D

[BigHairyBum]

1. With auto throttle off thrust levers can be used like any normal thrust levers on a jet.

2. By pushing the alt knob in, the a/c will follow the vertical profile in the FMGC (managed climb or descent). By pulling the alt knob the a/c will go into open climb or open descent meaning the a/c will climb or descend to the alt/fl selected in the alt select window.

Airbus, open climb/descend = Boeing, level change.

Airbus, managed climb/descend = Boeing, VNAV.

:confused: :confused: :confused:


Rip Barry White.

[Rwy in Sight]

Hello all,


I was speaking with two A-320 pilots yesterday and I was told there is a site that has a lot about short cuts or weird facts about the Airbuses.

Does any one know about that site (it is not pprune, which is well known to the individuals concerned)?

Cheers!

Rwy in Sight

[Port Strobe]

Regarding the thrust lever positions,

Quote BHB

1. With auto throttle off thrust levers can be used like any normal thrust levers on a jet.

I thought, very possibly wrongly since I don't know very much about these birds, that once the levers reach the CLB/MCT gate the autothrust is automatically "wakened" and so that would mean that manual thrust control would be limited up to climb power, thereafter autothrust kicks in. This doesn't sound terribly pilot friendly (or is it in actual fact for those that work with it?), so could someone explain what happens to the autothrust system with repect to the different gates please? Is there anywhere I can get more info on this at all?

Thanks for your time.

[Felix Lighter]

Not quite:

At take off when you advance the thrust levers (to FLEX/MCT or TOGA) you "arm" the A/THR.
Then, at acceleration alt when you retard the thrust levers to CLB the A/THR automatically engages.

At any other time, when you have A/THR OFF, the thrust levers move/act like and other jet.....fwd=more noise, back=less noise.

As an side note:

With A/THR engaged, the 'gates' (CLB, FLEX/MCT, TOGA) are just switches telling the autothrust the maximum thrust it has authority to use.

The reality is that having previously flown Boeing, I thought all this would be awful.........Ive actually found it very instinctintive (and Im not even French!) ;)

[Dale Harris]

spose it's a good thing then that they didn't do the usual froggy thing of having them operate backwards. Would've shortened a few Boeing pilot's careers I bet.

[T O G A Boy]

Regarding your enq. about the auto thrust. it is actually armed when u do the initial cockpit preparation(by turning on the flight directors). once the f.d. is on, then at take off roll, u read, MANFLex... or Toga on the FMA.., whatever detent u chose to take off. After when u get to the thrust reduction altitude(our company is 1500agl) except for countries with noise abatement procedures, then u select climb detent, and by this u are actually activating the auto thrust.. very clever indeed.

[Lemurian]

Hello all.
Boy,oh boy!!! Are we complicated!
How to use the knobs?Very simple :
-I pull the knob ,it means "I take over"that particular selection,be it heading,speed or vertical path.
-I press the knob,it means "George,it's your hand".
To answer a previous question,the site is called Airbus driver made and managed by a nice bunch of pros in the US.What is admirable is that they have de-mystified the A-320.
I am not ashamed to confess that I still brush-up my system knowledge with their site,that after eight years .Here it is :

www.airbusdriver.net

[Port Strobe]

Thanks for all the replies guys. I'll take the opportunity to point out my mistake that has been politely ignored so far, I meant FLX/MCT rather than CLB/MCT :O
That's cleared a lot up. So to clarify my understanding the a/c is lined up for take off with FD on (I take it take offs without the FD are like rocking horse sh*t??) the autothrust is armed and the levers are advanced to the TOGA or FLX/MCT gate. The normal 1500'agl acceleration height is reached and the levers are retarded to the CLB gate, at which point the autothrust takes control of the speed for you and accelerates towards 250kts or whatever you're cleared to. My main grey area before was on the approach say, you've diconnected the AP and FD and the autothrust as well. If you required a manual thrust setting greater than that at the climb gate you could pass the thrust levers through here and everything still remains in control of the PF? Am I right in thinking autothrust jumps in when the thrust levers reach FLX/MCT or TOGA even if previously off, since you would only need these in a go missed approach situation (which setting if at all??) Does the FD being on/off affect autothrust behaviour at all on approach? So can you have any combination of FD on/off and autothrust on/armed/off on the approach it behaves the same?

Thanks for all the replies again. Cheers.

[overstress]

Port Strobe

Not exactly - the autothrust is in the armed condition when lining up for t/o and it only becomes active after thrust reduction is made. The action of putting the thrust levers to the CLB gate activates the autothrust.

You can have FD off for the approach with autothrust active, it works very well, or you can switch the autothrust off at any time. There are very few instances where you would need more than CLB thrust on the approach as it would be difficult not to overspeed the flaps- the only time I can think of is S/E heavyweight having configured too early. CLB thrust is designed to climb the a/c!! The Autothrust will not re-engage automatically unless TOGA is selected.

I have flown the airbus for 7 years and I have very few complaints about the system.

[Port Strobe]

Thanks very much for that, I understand things much more clearly now. Thanks again to all that replied.