The US Marine Corps has begun its one-week operational readiness inspection of the Lockheed Martin F-35B-equipped Marine Fighter Attack Squadron-121 (VMFA-121) – the Green Knights – to assess whether the 10-aircraft unit is ready for combat.

The results will be briefed to Lt Gen Jon Davis, deputy commandant for Marine Corps aviation, who will decide whether to declare initial operational capability (IOC).

That declaration would mean the squadron is fit to serve aboard an amphibious carrier in a contingency operation, Marine Corps spokesman Maj Paul Greenberg tells Flightglobal. The inspection began on 13 July.

Based at Marine Corps Air Station Yuma in Arizona, VMFA-121 will be assessed on the quantity and quality of its pilots and maintainers, simulator flights, operational flights, and their ability to surge in exceptional circumstances. The maintainers will be assessed separately on their maintenance and supply programmes, to ensure they are able to keep the 10 F-35Bs in a combat-ready condition.

“Following the Marine Corps' F-35B IOC declaration, the aircraft will be ready for future deployments aboard the US Navy's fleet of amphibious carriers,” Greenberg says. “The first deployment is scheduled to take place in 2017, when VMFA-121 will deploy to Iwakuni, Japan.”

The USMC says it remains on track to declare IOC in July, but in a separate statement Davis said an August decision would also be acceptable.

“This will be an outcome-based measurement of readiness, assessing whether VMFA-121 as a whole is ready to perform the mission it is assigned,” Davis says. “If the operational readiness inspection is completed in July and we are confident that the aircraft are ready for world-wide deployment, then we'll declare IOC in July.

“If that doesn't happen until August, then it will be August. Bottom line is that we won't rush this; we are doing this the right way.”

The inspection comes after years of preparation and recent test flights aboard the USS Wasp amphibious assault ship. The Marines have a standing requirement for 340 short take-off and vertical landing F-35Bs to replace a combined fleet more than 400 Boeing AV-8Bs, F/A-18A/Bs and Northrop Grumman EA-6Bs.