The 'Lightning carrier' conceptUSS Tripoli completed flight deck operations with 20 F-35Bs as part of the US Marines' Lightning carrier concept demonstration. US Marine Corps photo by Sgt. Samuel Ruiz Taking its aviation capabilities even further, the US Navy used the Tripoli to test the "lightning carrier" concept, tasking the amphibious assault ship to function as a full-fledged carrier.In 2022, the Tripoli departed its homeport in San Diego for the Western Pacific, spending the first few months of its seven-month maiden deployment putting the experimental concept to the test.The assault carrier carried 20 F-35B stealth fighters on board the most ever loaded aboard a big-deck warship."We refer to the ship as 'assault carrier 7,' and 'assault' is traditional for an LHD and LHA," Capt. Joel Lang, then-commander of the Tripoli, told reporters at the time. "Typically, the air combat element is a blend of rotary and tilt-rotor in order to enable that assault force to go ashore. We are proving the tactics and the techniques and the procedures to employ the 'lightning carrier' concept."Produced by US defense manufacturer Lockheed Martin, the fighter jet has a stealth design to vastly reduce its ability to be tracked by radar and is touted as one of the world's most advanced fighters. The F-35B variant has a powerful propulsion system that gives it the unique capability of vertical takeoff and landing.Developed by Rolls-Royce, the lift fan delivers an additional 20,000 pounds of thrust on top of the aircraft's engine thrust, allowing it to land and take-off like a helicopter.The F-35B allows Marine aviators to operate aboard smaller flattops and makeshift airstrips, especially on expeditionary missions. With far more advanced capabilities and avionics, the F-35B is set to replace the US military's only other STOVL fighter jet, the McDonnell Douglas AV-8B Harrier, which is expected to retire by 2027.