The Joint Strike Fighter programme set out to do something the U.S. had never quite managed: replace a whole generation of legacy jets — F-16s, A-10s, F/A-18s, AV-8B Harriers — with one affordable stealth family. In a 1996–2001 fly-off, Boeing’s X-32 met Lockheed Martin’s X-35. The X-35 first flew on 24 October 2000, and its clever shaft-driven lift fan let it take off short, go supersonic and land vertically in a single demonstration. On 26 October 2001 Lockheed Martin won the contract, and the X-35 became the F-35.

The result was the costliest weapons programme in history — U.S. GAO estimates the lifetime cost above $2 trillion — but also the most-produced fifth-generation fighter in the world. Lockheed Martin delivered the 1,000th F-35 in 2024, and the planned fleet runs well past 3,000 aircraft across the U.S. services and around 20 partner and export nations.

Behind the F-35B’s cockpit sits a counter-rotating LiftFan, driven by a driveshaft off the main engine and producing roughly 20,000 lbf of cool vertical thrust. At the tail, a Three-Bearing Swivel Module rotates the exhaust nozzle about 95° downward in around 2.5 seconds, while small roll posts in the wings keep the jet level. The combination lets the F-35B settle vertically onto a flight deck or an austere strip — a feat no other production stealth jet can match, and the single hardest engineering problem the whole programme had to solve.

The F-35’s Gen III Helmet-Mounted Display is custom-fitted to each pilot’s head and reportedly costs around $400,000. It streams flight data, targeting cues and night vision directly onto the visor, and — fed by the Distributed Aperture System’s six cameras — lets a pilot literally look through the floor and walls of the aircraft. There is no traditional head-up display; the helmet is the display, and it is central to how the F-35 turns raw sensor data into a picture a single pilot can act on.

Three very different numbers get quoted for the F-35, and they mean different things. The flyaway unit cost of an F-35A has fallen toward roughly US$80 million in recent baseline lots — comparable to older fourth-generation jets — though recent production lots (Lot 18) have been reported above ~US$100M per aircraft. The figure critics cite, however, is the lifetime programme cost: the U.S. Government Accountability Office estimates it will exceed US$2 trillion across decades of development, procurement and sustainment for a fleet of thousands. When you read that the F-35 is “the most expensive weapon in history,” that is the programme-lifetime figure — not the price of one jet.