The chances of Darren Weir being a player in the Brisbane winter carnival rest with a Qantas cargo carrier in Melbourne.

Weir has horses booked to travel to Brisbane in the early hours of three mornings this week but the stable won't know until as late as 10pm whether they will be allowed to fly.

Cargo gets first call over horses which are then bumped from the flights.

The situation is made worse with a curfew in Sydney limiting the number of planes landing and taking off between 11pm and 6am.

This means Melbourne becomes a hub for cargo from around Australia.

Chris Calthorpe, who runs Air Horse Transport, says he's remaining optimistic Weir's horses, including Doomben Cup hopefuls Articus and Star Exhibit, can get to Brisbane.

"We're quietly confident without guaranteeing they'll get up there," Calthorpe told RSN927 on Tuesday.

"If all the stars align hopefully we can get some of Darren's horses away tonight and the rest on Thursday morning and then try and get some other trainers up there on Friday morning.

"We're flying with Qantas and the way the situation is, we're booked and we touch base with the airline around 9.30-10 o'clock tonight to make sure they haven't been inundated with freight.

"If that all goes to plan the horses will be at the airport at midnight, load them up on the plane and get them up to sunny Queensland."

Calthorpe says it has been an ongoing issue for 20 years but does not gain public attention unless it affects someone with a high profile such as Weir.

He said there had been problems in the past getting horses to Perth for the summer carnival, but in recent years a charter had been made available.

"If Perth didn't book a jumbo for the Railway Stakes no horses would get there," he said.

Calthorpe said the airlines and the racing industry needed to work together on the movement of horses for big carnivals.