While fighter jets are typically designed for a service life of around 6,000-8,000 flight hours, it is claimed that the F-35 has a service life of as much as 24,000 flight hours. But is this true? While the F-35A airframe’s structural lifespan seems impressive, the exact opposite may be true of the F-35B (or at least earlier models of the F-35B). The F-35 is the world’s most capable fighter jet and by far the world’s most popular 5th generation fighter jet. The US closely guards its valuable F-35 and even refuses to sell them to some of its allies.