I can not understand why anybody has a problem with retarding both thrust levers to idle on landing, or reverse on the bus, in spite of an inop reverser on an engine that has been locked out.
I have guesses, but they sound so ridiculous that I myself have difficulty in tryin to understand how the mistake was made.
In each case the CVR recordings alone prove that the pilots were utterly confused as to what had happened.
Bringing the throttles into idle is so intuitive that no one bothers to check when it's ommitted. Airbus SOP is there to make it as simple as possible to the critical phases of flight. Hence, regardless of manual or auto thrust, you bring BOTH to idle, then both into reverse. Whether one does the "both into reverse" is not relevant... it is the bring BOTH to idle that IS!
This is where we go into the arguments of moving T/L when on A/T or not. Again, although I prefer seeing moving T/L when on A/T, Airbus makes it simple... "Who gives a damn! bring BOTH to idle"... Besides, on A/T landing, one should (unless the procs has been modified) have one's hand on the T/Ls to ensure that idle thrust is reached when appropriate, either by monitoring the T/L position (Boeing & A300/310) or manually intervene T/Ls to idle (Boeing and Airbus)... this manual intervention is the common ground between moving and nonmoving T/L on A/T.
One of the problem is "relying on automation for the wrong things." It's the eternal problem in man/machine interface regarding automation... Take a look at this example:
Retrospectively he removed his hand compeltely from that thrust lever, it was midnight, dark cockpit.
Perhaps, one should say on a single reverse landing, "we have reverse one side only. Ensure both are idle upon touchdown."
It may be a small and seemingly useless reminder, but it reminds both of the matter and can assist in someone to check the T/L position if something is wrong on the landing roll.
The problem is very well put by the following:
So, under such pressure, 'Reverse one side only' translates in your mind as, 'Concentrate on the live one, forget the inop. bugger......."
And then the 'Retard' call stops, you get the nosewheel down OK but then there are no spoilers, no autobrakes, the runway is unreeling fast.........and there's no further warning about the throttles, they're past and gone, they don't even occur to you as the possible problem........and your off-sider is new to A320s.......twenty seconds to live.........
Can it really have been that simple?
That may be the answer to this t/l handling problem. Can it be that simple? Unfortunately, YES!
Presently, our manual prohibits the use of manual thrust except in extraordinary circumstances such as a clear intent to "practice" in a benign ATC/operational environment. Many believe this to be a fundamental mistake and have fought such prohibition for years. We finally lost. Now, one disconnects the autothrust at one's peril should anything happen. Many crews used to fly approaches manually, including manual thrust levers, all the time and I personally taught it in instructional situations and encouraged it in regular line flying. No longer; the "risk" of blame is too high. In my view, competency with the machine is thereby lost however and, with such AOM restrictions, the relative loss of competency becomes self-fulfilling problem or a vicious circle. It is a big issue, as you likely know.
Back to the automation interface problem... your sentiments shared!
Is it the same when retarding to idle in the flare - that is, you have to pull the levers firmly back, against the resistance of the 'detent' mechanism, to make sure that they are firmly seated? How much 'feel' do you actually get?
On the 320 you bring it back to the idle stop, then when going to reverse you pull the latches to enable it to go to reverse... right? For going out of reverse, bsieker has answered.
Don't forget that in aviation, the "KISS" rule strongly applies: KEEP IT SIMPLE STUPID
Golden rule!
Airline travel is statistically so safe, whatever sort of aeroplane you're flying in, that it would be half a lifetime before the figures alone showed that one particular type was significantly any less safe than another.
It's safe, but when something bad happens, it's gruesome. The fact that it's probably the safest mode of transport is also overhyped. This is probably why when an air accident happens, everyone looks at it... a high speed bus impact resulting in multiple mutilations of bodies followed by burning probably wouldn't attract so much attention.