I talked to you about this before.
As we're using the aircraft, the new aircraft come online. The air force is working out the mathematics of taking delivery of the newer aircraft and transitioning out. All that is being worked on while we actually carry out those missions.
I've been seeing some of the work they've been doing, putting a lot of science behind it, and I'm very impressed with the work the air force is doing and how that transition is going to go.