Pilot Savchenko is on plane bound for Kiev from Russia

Ukrainian military pilot Nadezhda Savchenko looks out from a defendants' cage as she attends a court hearing in Moscow March 4, 2015. REUTERS/Maxim Zmeyev/File Photo

KIEV (Reuters) - Detained Ukrainian servicewoman Nadiya Savchenko is on board a plane returning to Ukraine from Russia, a source close to a deal to swap the pilot for two Russians held by Kiev said on Wednesday.

"They are coming back," the source said, confirming that Savchenko was on the plane.