Qantas chief executive Alan Joyce says Boeing's new 787 Dreamliner is a game changer but will not be enough to fix the airline's ailing international business.

The airline has 50 of the Boeing 787s on order but will not receive any until early 2013.

Mr Joyce defended Qantas' reputation following his decision to ground the entire fleet two weeks ago, saying he had received more compliments than complaints.

He says he is hopeful a deal can be struck with the three unions it is battling before Fair Work Australia's 21-day deadline expires.

But he would not comment on how the negotiations were progressing.

91st Anniversary

Aviation enthusiasts caught their first glimpse of the plane yesterday, when a test model landed at Sydney airport as part of Qantas' 91st birthday celebrations.

The Dreamliner made its inaugural flight last month after being delivered to Japanese airline All Nippon Airways three years late due to production delays.

Boeing says the 787 is lighter, quieter and greener than other similar aircraft.

Its fuel consumption and greenhouse gas emissions are 20 per lower than its competitors, and more than 50 percent quieter.

The 787 travels to Melbourne on Thursday.