That's interesting Centaurus.
I have the greatest of respect for someone such as Mr Zizovski, I really do.
I'm just trying to imagine what difference whacking the thrust levers closed makes compared to taking one or two seconds to close the thrust levers to idle and allowing them to gently rest against the stops.
As far as time verses engine thrust is concerned, I see no difference.
As far as freaking out the pilot next to you, I see a difference.
Some points worth considering.
1. If I start reducing thrust at the same time as Mr Zizovski, but take 2 seconds longer to reach the idle stops, at the very worst, all you could say is that I am adding 2 seconds worth of energy to the aircraft. Compare this to the total amount of kinetic energy 60 tons of metal has at 130 kt and you will find that it is insignificant.
But even this is not true. You are not adding two seconds of thrust because the majority of the thrust is reduced at the same time. Remembering that Thrust vs % N1 is not linear but more parabolic. i.e. reducing N1 from 60% to 42% reduces the thrust by half. Reducing from 60% to 30% reduces it to a quarter of what it was.
2. What is the absolute minimum time it takes the engines to reduce from approach thrust to flight idle? (60% to 25% N1) Three seconds? (that would be an absolute minimum I reckon).
If so how does taking three seconds to bring the thrust levers to idle make any difference to the rate of engine thrust reduction? In other words I am moving the thrust levers as fast as the engines can react, moving them any faster would make no difference to what the engines do.
Same thing if I am increasing thrust. If the thrust levers are at idle and I want go-around thrust, if the engines take 5 seconds to spool up, it doesn't matter if I take 1 second or 3 seconds to move the thrust levers to the fwd stops, it will still take 5 seconds for the engines to spool up.
3. How long does the auto-throttle take to close the thrust levers during an autoland? My guess is somewhere around five seconds.
May I throw a cat amongst the pigeons??
Jacobson Flare.
There have been numerous discussions about that one.
(Yes I do think it works well.)