Requisitioning civilian airliners for wartime lift

Could a government simply requisition civilian airliners for military airlift during a war?

It may have legal powers to do so, but dispersed aircraft, international ownership, and competing jurisdictions make modern requisition much less straightforward.

The availability of civilian airlift in a war is more than a question of how many aircraft exist. It also depends on the conflict's duration and whether airlines and their financiers are prepared to risk valuable airframes. Many aircraft belong to banks and may be dispersed across several jurisdictions when mobilization begins. Orders in Council and statutory powers are cited as possible British mechanisms, with emergency prerogative action providing speed before longer-term measures take effect. Modern aircraft also spend much more time airborne and less time sitting within easy government reach than their 1930s predecessors.