Flight time differences between A/C types?

Following on from the recent thread "LGW-ANU why 40 min added?" Where wwings mentioned that the 346 is faster than a 343
I was wondering if anyone would know what the flight duration difference would be between the 343 and 346 on a route like say LHR-NRT?
I do remember a flight time of 10:20mins to NRT once (I think it was in mid April) which was amazing.

The max. cruising speed difference between the A343 and A346 is marginal and the optimal flight speed for maximum fuel efficiency may well be the same. Then of course weather conditions will have a large role to play, and climb and descent / holding will factor into the actual time, so the journey time could be identical or different due to many inputs and just looking at a marginal cruise speed difference won't give you a comparable flight duration.

However, in still air conditions with a distance between LHR-NRT of 5,974 miles if both operated at cruise speed from the moment of take-off to the moment of landing (which of course is impossible) then:

A343 cruise speed of 537 mph = 11 hours 8 minutes.
A346 cruise speed of 543 mph = 11 hours 1 minute.

Its the 747's which are noticeably quicker, this is why you often find BA operating a 30 minutes shorter flight between two city pairs also served by VS using an A343/346.

Thanks Slinky
You guys are really knowledgeable.
How do you learn all this info ?

Its the 747's which are noticeably quicker, this is why you often find BA operating a 30 minutes shorter flight between two city pairs also served by VS using an A343/346.

Yes indeed, a 747 flying to NRT under the same conditions as above (although still not realizable) would do the trip in 10 hours 33 minutes ...

gfonk, Google is our friend .

Yes indeed, a 747 flying to NRT under the same conditions as above (although still not realizable) would do the trip in 10 hours 33 minutes ...

wow that would be awesome (although I realise as slinky says that this is not a possibility even in the near future[which is a shame]. That could be also be due to the popularity of the route in comparison with NYC). There could be the odd days where it could be even quicker :0 as I said I have once done NRT in 10hrs 20mins on a 346. Obviously that was very favorable flying conditions. The average is usually 1hr longer.

gfonk, Google is our friend .

lol :0 slinky.