Qantas chief executive Alan Joyce said the airline had challenged Airbus and Boeing to produce an aircraft capable of flying direct to Heathrow and New York from Sydney and Melbourne.

"And we're getting close," Mr Joyce told reporters in Perth on Saturday.

"By the end of this year, we'll know if both aircraft can do it."

If both can manage the range, Qantas will call for tenders next year and place an order, with the aircraft likely to be ready by 2022.

"It's not that far away and the opportunity for all of us in that is quite massive," he said.

The new 14,498km route from the West Australian capital to London on Qantas' new 787-9 Dreamliner will take about 17 hours, shaving several hours off the journey for those departing Perth.

For travellers coming to Perth from Melbourne, however, the total time saving for the journey to Heathrow is only about one hour.

But travellers from London to Melbourne and vice versa are allowed one free stopover in Perth.

Convenience is also expected to be a drawcard, given passengers fly to Perth then embark on their long-haul journey from the same airport.

Previously, travellers had to take the short but fiddly trip from the domestic airport to the seperate international terminal.

That's no longer necessary for those flying Qantas because Terminal 3 at Perth Airport has been converted to a dual domestic-international operation, hosting all of the flying kangaroo's overseas routes.

Mr Joyce said the airline expected to make a profit on the route from the very first flight, which hadn't been seen in the industry for a long time.

"It has more business class and premium economy seats than we've ever put on an aircraft and we're filling them," Mr Joyce said.

"The forward bookings were up over 90 per cent so the economics of this route are looking very strong from day one."

The route is expected to improve tourist numbers from Britain, providing a much-needed boost to the economy.

That's especially needed in WA, given data earlier this month showed the state recorded Australia's only fall in overseas tourist numbers over the past year, with its isolation proving a turn-off.

KEY FACTS ABOUT PERTH-TO-LONDON DIRECT FLIGHTS

* The first regularly scheduled non-stop service between Australia and the UK, and the longest Boeing Dreamliner flight in the world

* Longest flight on the Qantas network (14,498km), followed by the airline's non-stop Sydney to Dallas service (13,730km)

* When travelling from Heathrow to Melbourne, one free stopover is permitted in Perth in each direction

* Eight Boeing 787-9 Dreamliners have been added to Qantas' fleet for the new service

* The aircraft seats 236 passengers

* Windows are 65 per cent bigger than comparable aircraft and can be adjusted electronically

* New cabin lighting includes a simulated sunrise to gently wake passengers on morning flights

* Turbulence-sensing technology smooths out the ride while various solutions reduce cabin noise.

Australian Associated Press