A very detailed synopsis on the US F-35 program status from Jane's DW as far as aircraft and numbers/squadrons are concerned (posting a summary since the article is currently behind a paywall):
With the US Marine Corps (USMC) having declared initial operating capability (IOC) for the F-35B version of the Lockheed Martin Joint Strike Fighter (JSF) in 2015, the US Air Force (USAF) having done the same for the F-35A in 2016, and the US Navy (USN) set to follow suit with the F-35C in late 2018 or early 2019, the US military is at the beginning of the process to introduce what will be the country’s premier combat aircraft for decades to come.
US Marine Corps
As the first service to declare IOC, the USMC is at the forefront of not just the US effort to introduce the JSF into service, but also of the global effort. With a programme of record for 353 short take-off and vertical landing (STOVL) F-35Bs and 67 carrier variant (CV) F-35Cs to be spread across 16 and four squadrons respectively, plus an additional two training units, the corps is already well ahead on its path to fielding the F-35.
To date the corps has stood up Marine Fighter Attack Squadron (VMFA) 121 ‘Green Knights’, initially at Marine Corps Air Station (MCAS) Yuma in Arizona and now at MCAS Iwakuni in Japan, and VMFA 211 ‘Avengers’ at MCAS Yuma as its first two operational F-35B units. The next three operational squadrons – VMFA 122 ‘Crusaders’, VMFA 314 ‘Black Knights’, and Marine Fighter Attack Squadron (All-Weather) VMFA(AW) 225 – will transition over from the Boeing F/A-18 Hornet in the coming months, with VMFA 314 being the first of the corps’ four F-35C squadrons. The USMC will first transition over its Hornet units before doing the same with its Boeing/BAE Systems AV-8B Harrier IIs.
In addition to its current and near-term operational units, the USMC has one training unit in VMFAT 501 at MCAS Beaufort in South Carolina, as well as VMX-1 Test Squadron at Edwards Air Force Base (AFB) in California. This unit will move to MCAS Yuma, where it will co-locate with the USMC Operational Test and Evaluation (OT&E) unit and weapons school.
The transition of VMFA 121 from MCAS Yuma to the 1st Marine Aircraft Wing (MAW) at MCAS Iwakuni in January 2017 was a key milestone in the F-35B programme for the USMC, coming just six months after IOC for the type was declared in July 2015. Being the first operational unit (the squadron was actually stood up in November 2012), VMFA 121 has been heavily involved in developing the corps’ tactical and austere capabilities for the jet.
In early April 2017, just four months into its inaugural overseas deployment, VMFA 121 trialled the use of ‘hot’ ground refuelling conducted from a USMC Lockheed Martin KC-130J Hercules from Marine Aerial Refueler Transport Squadron (VMGR) 152. As noted by the USMC at the time, this aviation-delivered ground refuelling (ADGR) trial was the first time that the F-35 had been fuelled with the engine running to enable the aircraft to be replenished in austere locations that are not equipped with the normal infrastructure. This “stepping stone” test, as the marines described it, was followed in September by the first ‘hot loading’ exercise of live missiles, again to develop the tactical capabilities of the aircraft.
With VMFA 121 now operationally deploying the F-35B overseas for the first time, the USMC will conduct the first operational maritime deployments aboard its Wasp- and America-class amphibious assault ships this year. According to Gen Davis, the corps will embark six to eight F-35Bs on shipboard Marine Expeditionary Unit (MEU) task forces.
US Air Force
Having declared IOC for its conventional take-off and landing (CTOL)-variant F-35A in August 2016, the USAF is now just beginning to ramp up its aircraft numbers. To date the USAF has received approximately 120 F-35As, which are distributed across five bases in the contiguous United States (CONUS).
What is interesting about that number is that it seems like a lot, but we are going to grow to 1,763 aircraft over the life of the programme. So in many ways, even though we have had the aircraft for a number of years already, we have only really just begun,” a USAF spokesperson told Jane’s in October 2017, adding, “The hallmark of the programme over the coming years will be the exponential growth of the number of F-35s and in the number of USAF bases in the US and overseas [such as at RAF Lakenheath in the United Kingdom in the early 2020s].”
Currently the USAF has F-35As located at Edwards AFB in California; Hill AFB in Utah; Eglin AFB in Florida; Luke AFB in Arizona; and Nellis AFB in Nevada. Hill AFB is the combat-ready unit with the 34th Fighter Squadron (FS). If a combatant commander required the F-35A, then this is the unit that would be deployed. As evidence of the 34th FS’ capabilities, in April/May 2017 the unit was deployed to the United Kingdom and across forward bases in Europe. “That training deployment was a huge milestone for that unit to demonstrate its combat readiness – and was also a significant signal from the USAF to show the world that it is ready with this stealth fighter and that we can take it any place that we need to,” the service representative said.
Eglin AFB and Luke AFB are pilot training bases for USAF and international F-35A customers, as well as for USN F-35C pilots, while Edwards AFB is where developmental testing is carried out by four USAF aircraft. The final location where USAF F-35As can currently be found is Nellis AFB, which is home to the 'Red Flag' exercises.
The USN is set to receive 273 CV F-35Cs over the life of the programme. For the service the urgency to introduce the F-35 into service has not been as acute as it has been for the USMC and USAF, given that it is still receiving Boeing F/A-18E/F Super Hornet and EA-18G Growlers fresh from the factory. As such, it will be the last of the three services to declare IOC when it does so toward the end of this year.
Despite the lack of urgency, and contrary to anecdotal reports that of all the US service arms the USN is the least keen to receive the F-35, the service is keenly anticipating the arrival of its future primary combat aircraft. As one senior navy official, speaking under the Chatham House Rule, put it, “The US Navy has never had a fifth-generation stealthy multirole fighter before – and there is much to be excited about.”
In terms of its F-35C stand-up to date, the USN has so far equipped Strike Fighter Squadron (VFA) 101 ‘Grim Reapers’ and VFA 125 ‘Rough Raiders’ as the East and West Coast Fleet Replacement Squadrons respectively. The first operational fleet unit will be VFA 147 ‘Argonauts’, which will transition from the F/A-18E this month.
The service is now anticipating the Block 3F (full combat) software release early this year, with the next phase of operational testing to begin on the Nimitz-class aircraft carrier USS Abraham Lincoln shortly thereafter. IOC is expected between August this year and February 2019, with the first deployment scheduled for the carrier USS Carl Vinson in 2020/21. Once their future air components are fully stood up, each carrier will be equipped with two F-35C squadrons to complement the two F/A-18E/F squadrons and one EA-18G unit that will also be embarked.
The USN has taken the F-35C to sea for trials four times already and, notwithstanding a tail hook redesign and an issue of excessive head movement for the pilot during catapult launches, the trials have proven successful. “The F-35 has earned her sea legs, and for US Navy aircraft to be operationally relevant we lower our tail hooks and land on big deck aircraft carriers. We have now taken it to sea on [four] different occasions, and have extended the envelope in deteriorating weather conditions, varying sea states, and in both day and night operations. These involved pilots who were new to the F-35; we brought them out to the carrier and the tests proved to be very successful,” the navy official said, adding, “The tail hook was redesigned and is now working well. These kinds of things are going to happen with a new airplane, especially when you bring them to sea where there is less margin for error and much greater forces at play.”
One aspect of the F-35C’s carrier performance that has pleased the navy has been the aircraft’s automatic landing technology, or delta flight path (DFP) mode, as it is officially known. According to the official, “The delta flight path advanced landing capability is something that we are quickly finding is revolutionising our ability to land on the aircraft carrier more accurately. As naval aviators we tend to target the number two or three wire on the flight deck, and with DFP we are able to do this at a phenomenally consistent rate.”
He went on to explain that, “When VFA 101 was doing trials they had zero bolters [ie no aircraft having to abort their landing]. The DFP is coming online at the same time as the Magic Carpet [system] that has been developed for the Super Hornet; it uses the exact same technology. The two systems will revolutionise carrier operations, reducing the time steaming into the wind and the number of tanker aircraft that are needed.”