Latest F-35 Airframe Contracts Coming in Spring; Engine Deal Later in 2025 Jan. 17, 2025 | By John A. Tirpak Contracts for F-35 airframes in Lot 18 and 19 should be signed in the spring, but an engine deal is still not in hand and could take months longer. The delays don't seem to be driven by anticipation of how the new Trump administration will ...