Like my keyword heavy topic?
I got a response from Fantasy Flight regarding weather Apollo could jump in a viper and take an action - including XO - and it all resolve immediately.
The short answer is that it is the same as any other time. Save those Soe and XOs!
Tim Uren: [H]e can pilot one of the vipers and immediately take any action available to him. Specifically this happens between B. and C. of the "Set Up Battle of the Ionian Nebula" step. Hope that helps!