United Airlines has downgraded some of the first Dreamliner services on its new Melbourne-Los Angeles route from the brand new Boeing 787-9 to the slightly smaller and older 787-8 model.
The airline will launch the route with a new 787-9, the first of which was delivered to the US carrier last week, on October 28 eastbound.
But from October 29 to November 16, it will use a 787-8 on three of the six days per week during on which the route operates. The 787-8 will operate westbound on Wednesdays, Fridays and Sundays and eastbound on Tuesdays, Fridays and Sundays.
United's corporate communications department said the change had been made due to "aircraft availability" rather than weak demand from passengers.
"Interest in the nonstop service from Melbourne to Los Angeles has been meeting our original expectations and we anticipate continued strong demand going forward," the company said.
From March 12, the service is due to become daily.
United's Melbourne-Los Angeles flights are poised to be the longest route in the world flown by a Dreamliner of any type. However, the 787-8 has a shorter range than the 787-9.
United said it planned to block a "small number of seats" on the westbound flights from Los Angeles to Melbourne to ensure the aircraft had enough range.
United's 787-8 seats 219 passengers, including 36 in business class, 70 "economy plus" seats with extra legroom and 113 in economy class.
The 787-9 seats 252 passengers, including 48 in business class, 88 in economy plus and 116 in economy class.
United's decision to offer direct services from Melbourne to Los Angeles rather than providing one-stop services via Sydney led Virgin Australia to abandon its three weekly 777 Melbourne-Los Angeles flights in favour of a daily offering on the Brisbane-Los Angeles route.
Qantas Airways, in turn, has announced it will add an extra three weekly 747 flights from Melbourne to Los Angeles from January 21.
Air New Zealand in July became the launch customer for the 787-9. It has been flying the aircraft on select services between Auckland and Sydney and plans its first Auckland-Perth flight on Friday ahead of the formal launch date for that route on October 15.
United and Air NZ have both chosen a relatively tight nine-abreast seating configuration in economy class in line with most airlines.