Qantas 747 to be R. R. engine test bed.

[bob10]

70 million KM's. flown. Sounds incredible.

Retired Qantas Boeing 747 finds new life as flying Rolls-Royce testbed (https://thenewdaily.com.au/life/tech/2019/10/22/qantas-boeing-747-rolls-royce/?utm_source=Adestra&utm_medium=email&utm_campaign=Morning%20News%20-%2020191023)

[101RRS]

Its great to see the aircraft getting a useful second life.

I am also surprised that Qantas is not considering late 747s for its planned future extra long haul flights like they tested with a Dreamliner last week. The Dreamliner does not have the range for Sydney to New York in a commercial configuration and the only way it managed that was reducing passenger numbers to 50 and filling up with extra fuel. As it was they only had 1 hours worth of fuel left but I assume that was in addition to mandatory reserves.

With one of the later 747s they would not have the range with a full 500 odd passenger load (in fact range is less than a fully loaded Dreamliner) but if reduced to the 300 odd capacity of the Dreamliner then I understand the 747 can easily do the trip.

The issue is cost and efficiencies as clearly the Dreamliner is much more efficient but the 747 has the room to provide the right environment for passengers in ultra long haul flights and still carry the same number of passengers of smaller aircraft over the full distance.

I certainly applaud Qantas for experimenting with Ultra long haul flights but at the moment aircraft technology is not quite there for full load (300+) commercial flights.

Garry

[JDNSW]

Problem with the 747 (apart from the fact that they are all old) is that not only are they less efficient than modern designs, but they need a lot more maintenance. Four engines instead of two, for a start, but also all their systems need more maintenance.

I expect that these ultra-long routes will be served by long range variants of current modern aircraft, with useful range increased by a combination of improvements in engine efficiency and increased MTOW, probably enabled by the more efficient engines also having a greater take-off power.