When I was flying the 727 we had a contest between the pilots on this subject. The contest, when the weather was VMC and ATC traffic load low, was two fold, first that when cleared from for descent at pilots discretion from the mid altitude, around FL 240, you closed the throttles, and timed the descent to hit 10,000ft. and 250 kts IAS at the same time. Then, again with the weather and ATC cooperating, you would continue the descent to arrive at the OM, or if no ILS a five mile final, at glide slope intercept altitude, start extending the LEDs/flaps/gear and then at 500 feet in landing configuration you would touch the throttles bring up the power for landing.
After a while it became quite easy. Oh, you were allowed to use the boards, but if you did, you only won one beer.
I landed the 727 only one time never touching the throttles from 10,000ft and it was not intentional. I think I was set up by the guy in the right seat and the FE. We were landing at NAS Miramar (of 'Top Gun' fame), I had coasted in from the west for a right hand downwind. I was at flaps 15 still descending at the midfield point when I was distracted looking for a pair of F-14s that were called out to us as traffic. After I finally located the F-14s I realized that I had passed the end of the runway, how far I didn't know. So I ask my good buddy in the right seat how it looked for turning base, this was the following conversation, sort of;
Guy in right seat=RS
FE=FE (duh)
Me=Me (of course)
RS, "It looks fine, go ahead and turn in."
Me as I look at him, "You sure?"
RS, "Oh yeah, it's fine."
FE peering out the right side cockpit window, "Oh yeah, you can make it."
Me, I start the turn and call for 'gear down'. (Still at flight idle, where the engines had been since we left 10,000ft.)
Me when I finally see the runway, "Jesus Christ, we're too close, flaps 20 then on speed flaps 30, before landing checklist at flaps 30."
RS, "Huh, yeah, I just might have called that just a mite too soon. Flaps moving."
Me, "No sh!t.'
At this point I place my hand on the throttles, more out of habit in this case instead of need.
Me, "Okay, we will touch down in the touchdown zone, but at what airspeed I've not a clue, but we have 12,000ft of runway so stopping will not be a problem, you two a$$holes."
We landed without me ever moving the throttles, stopped with moderate braking with 5,000ft of runway left. That night in Phoenix where we RON my two 'buddies' bought all my beers that night.
So the point of this post is, this idea can and will work with weather and ATC cooperating. However, I don't have clue if an fly-by-wire Airbus can do total flight idle descent from altitude to landing.