Glossary

S

SDD - System Development and Demonstration

The F-35 program phase that includes manufacturing and testing 19 aircraft - 13 flight test and six ground test F-35s.

Stealth

The ability to evade detection by radar, infrared sensors or emission interception.

STOVL - Short Takeoff And Vertical Landing

The F-35B variant is also referred to as the F-35 STOVL.

Supersonic

The speed of travel that exceeds the speed of sound, which is considered to be Mach 1.

Sustainment

The process of maintaining aircraft readiness with logistics, maintenance and fleet data.