2 hours? It's not a question that can be answered because the endurance goes out the window once Biggles starts manoeuvring to take a shot at Von Richtofen.
Iam not sure if any endurance figures have been released, may still be classified as they would give a fair bit away in terms of ideal cruise speeds and such. The engines are still being developed so the final figures may vary quite a bit before the craft enter service in 4/5 years.
