MotoGP says it is committed to running the Japanese Grand Prix this weekend even if fog means no track activity is possible until Sunday.
All Friday practice sessions had to be cancelled as fog at Motegi meant the medical helicopter could not land under Japanese law.
MotoGP race director Michael Webb said various options had been considered for relocating the helicopter or ensuring other methods of transport, but none were deemed feasible.
"Many, many alterations were proposed - anything that was possible," he said.
"No reasonable solution has been found.
"The weather forecast for Saturday and Sunday is somewhat brighter.
"We're committed if at all possible to run this race."
If conditions allow running on Saturday morning, practice sessions will be extended before the usual schedule applies from qualifying.
But if fog returns for some or all of Saturday, Webb said plans were in place to move the helicopter to the circuit in time for anticipated better weather on Sunday.
"If the helicopter still cannot fly by tomorrow afternoon, it will be dismantled, shipped by road to the the circuit and reassembled for Sunday morning, when we expect conditions to be significantly better."
Should conditions not improve until Saturday lunchtime, the afternoon will be given over to practice sessions that Webb said will run "as long as possible", with qualifying and the races all on Sunday.
If no running is possible at all on Saturday, a draft schedule has been created that would squeeze practice, qualifying and races for all three grand prix classes into Sunday.