Originally Posted by ELAC
Quote:
Am I wrong that there is just no action for the PF to perform wrt the throttle levers in a conventionally designed aircraft?
pj
You seem intent on believing what you want to believe regardless of the facts.
On *most* conventionally designed aircraft you have to pull the thrust levers to idle when you flare, there is no such thing as autothrust in a very large percentage of airplanes. That's the way it's worked on the B727 and every other non-FBW aircraft I've ever flown. Even on most conventional aircraft with autothrust, such as the B757, this is usually disconnected at the time the pilot disconnects the autopilot leaving the thrust levers under manual control. If you don't pull them back yourself when you land they produce whatever thrust the lever demands. This was never pointed out to me in training as a design flaw.
The difference you seem to be getting at is between the Airbus and certain recent Boeings which are landed manually with autothrust active. The Boeing TLs move whereas the Airbus ones do not. There are arguements for either system when looked at holistically, but the Airbus system is not one iota more complicated or different in philosophy in this particular respect than a B757, B727 or a DC-3 for that matter. You want idle thrust, pull the levers to idle. Simple.
your are still missing hugely important diffence.
In the Boeing et al, the thrust matches the lever position - if you do not pull the levers back, then the thrust doesn't come back. Doesn't matter wether you are manul landing or autolanding - the levers will move the same way
In the Airbus the thrust changes without pilot intervention or the levers moving.
For example in this accident.
In the Airbus - during the apporach - the thrus is at a normal approach setting, then during the flare the thrust comes back to idle, then once landed the thrust spooled back up again - what did the pilot do to cause the thrust setting to change twice? Nothing.
In a Boeing / MD etc etc, the ONLY WAY that that sequence of events could have happend is if the pilot pushed the thrust back up after landing.
I.e for the boeing to have thrust spooling back up on the rwy after landing requires a positive pilot input. Wheras the airbus only requires an error of omission, i.e the pilot forgets to do something.
I still maintain that if a simple error of omission has such catastrophic consequences then it is the fault of the man-machine interface.
Just as many people are saying that forgetting to pull back the levers on landing is a completely incomprehensible thing for a pilot to do, then so are aircraft with non-moving thrust levers.
I HAVE to pull my levers back to land - the aircraft won't land without it (well it will, but a long, long, long, long way down the runway - 99.9% of pilots would have gone around by that point on a short runway), then as soon as my wheels hit the ground, my spoiler / autobrake logic is already satisfied.
On the airbus the thrust will idle, and the aircraft land without the thrust levers being pulled back. The aircraft then needs a further pilot action to satisfy the spoiler / autobrake logic. However alien it may seem to some, that action can be, and has been forgotten.
THAT my friend is the crucial and now fatal difference between the two systems