On an Arizona runway nearly 4,900nm removed from Le Bourget’s festivities, 10 selected Lockheed Martin F-35Bs will be preparing to make history as the Paris air show gets under way.

The US Marine Corps (USMC) is set to declare later this year the 10 F-35Bs assigned to the VMFA-121 Green Knights squadron at Marine Corps Air Station Yuma, Arizona, as the first unit to achieve initial operational capability (IOC). Nearly 14 years after the US Department of Defense awarded Lockheed the Joint Strike Fighter development contract, the first of the three F-35 variants will finally be an operational system.

The short take-off and vertical landing (STOVL) F-35B has still not attended an international air show, but it will soon be available for combat.

Not much is likely to change for VMFA-121 in the months following the IOC declaration. The unit will be available for operations if called on, but it is not scheduled for its first deployment – to Iwakuni, Japan – until 2017. By that time, the US Air Force should have declared the first squadron of the conventional take-off and landing F-35A to have achieved IOC, with the US Navy following suit in 2018 with a first squadron of carrier-variant F-35Cs.

“We’re on track to do that [Marines IOC], on track for Air Force IOC the following year,” assistant secretary of defense for acquisition, technology and logistics Frank Kendall told reporters on 29 May adding that, after that, the navy and international partners would start declaring IOC.

“We’re continuing to execute to the plan that was baselined in 2011, so good progress on all of those things. We’re either meeting or exceeding our projections for cost and schedule.”

Getting to this point has been a struggle, especially for the F-35B. As the world’s first operational fighter that combines supersonic speed and STOVL capability, the model is a technological breakthrough. In fiscal year 2015, each propulsion system alone – Pratt & Whitney F135 engine, Rolls-Royce LiftFan and other major components, such as wing-mounted roll-posts and a three-bearing exhaust swivel nozzle – cost $32 million.

Proving the F-35B can operate reliably on an amphibious carrier was the last remaining hurdle before the Marines could declare IOC. In previous tests aboard the amphibious assault ship USSWaspin 2013, the F-35B showed that it could take-off and land as it was designed. But the deployment revealed other issues, particularly in the logistics department.

It was discovered, for example, that the system the USMC currently relies on to automatically monitor and diagnose faults, order repairs and keep track of spare inventories – Lockheed’s autonomic logistics information system (ALIS) – could not physically fit aboard theWasp. So, all maintenance actions were co-ordinated remotely from Lockheed’s global F-35 sustainment hub in Fort Worth, Texas. As a result, the programme funded a deployable version of ALIS, which accompanied the F-35B squadron on the latest round of embarked tests.

One final operational assessment staged aboard theWaspfrom 18 to 27 May was intended to answer the ALIS issue and many other questions about the F-35B’s ability to go to war.

Ninety-one marines, including 10 pilots, joined six F-35Bs – a shipboard squadron – aboard theWaspin the Atlantic Ocean for eight days of flying, which included 108 sorties in 85.5 flight hours. The pilots flew sorties focused on carrier qualification, air interdiction, defensive combat air, air traffic management and supporting a rescue mission for a simulated downed aircrew.

“I would say highly successful,” says Lt Gen Jon Davis, the Marines’ deputy commandant for aviation.

Although the public focus was on the number of sorties, the USMC were most interested in what was happening on and below deck. “We focused this carrier period on logistics and sustainability,” Davis says. “So, what would it be like to go do that and what would it take to include a lot of force maintenance actions, both above deck and below deck. That all kind of worked how we thought it would. There were a couple of small things we discovered – an additional tool here or an additional part there, but the bottom line is we accomplished all of the stuff we wanted to, to include flying an [F135] engine on board the ship on the [Bell Boeing] V-22.”

The size of the F135 engine had raised concerns that one could not be physically loaded and carried by a V-22 from the shore or another ship to an amphibious carrier deck. However, the US Naval Air Systems Command, Bell Boeing and P&W developed a cradle for the F135 to load inside the tiltrotor, ensuring that spare engines could be dispatched to the ship if needed.

“We flew it on on the 21st of May and flew it off on the 27th, and moved that thing around like we were putting it into an aircraft,” says Davis.

A thermal coating on the deck also “performed well”, Davis adds. The F135 engine produces nearly twice the thrust of the R-R Pegasus engine on the Boeing AV-8B Harrier, and the heat exhaust emitted by the F-35 during a vertical landing can melt an untreated carrier deck. So the protective coating makes sure the aircraft can operate safely aboard ship.

Most importantly, the deployable version of ALIS also “worked very well” aboard the ship, Davis says. That “allows us to achieve our turnaround times,” he adds. “We have good interoperability with ALIS on board theWasp, and there’s an organic system now on that ship.”

Maintaining the F-35B’s very low observable signature to radar was another objective of the last deployment. Previous stealth aircraft required extensive post-flight maintenance to re-apply radar-absorbent materials and adhesives that cover gaps on panels.

“We proved we could do that at sea as well,” Davis says. “All in all, a successful deployment. We got what we wanted out of the shipboard period, and now we are tracking the additional items we have to do to accomplish our IOC objectives.”

In general, the IOC term in the military’s acquisition lexicon simply means that a new weapon system meets the user’s minimum operational needs. For the F-35B, this is defined as the ability to carry internally two 454kg (1,000lb) bombs or two 227kg bombs and two Raytheon AIM-120 AMRAAM air-to-air missiles.

It also includes a suite of software-enabled capabilities that are only partially complete. In 2010, the Marines agreed to declare IOC in 2015 with a degraded software build called Block 2B, while the USAF is waiting for Block 3I software in 2016, which includes updated hardware. The navy's IOC declaration is waiting for the availability of Block 3F in 2017.

In March, F-35 programme executive officer Lt Gen Chris Bogdan acknowledged that a portion of the Block 2B software capability would not be ready when the USMC's window for declaring IOC opens in July.

One of the reasons for calling the F-35 a “fifth-generation fighter” is the aircraft’s ability to fuse data from multiple sensors, both on board and from other aircraft. The pilot can use that information to track and positively identify targets that could not be identified using a single sensor. But the Block 2B software’s fusion algorithms are still not working properly.

In formations of more than two aircraft, the F-35’s sensor fusion computer often gets confused: each sensor detects a target with varying degrees of resolution, and so the pilot is told by the computer that there are several targets where there is only one.

It is a problem that the navy encountered when developing a similar sensor fusion engine for the Boeing F/A-18E/F Super Hornet, programme manager Capt Frank Morley told Flightglobal in a recent interview. For the Super Hornet, the air-to-ground capability that is causing problems for the F-35B’s Block 2B software was still challenging, but turned out to be the easy part. Making the sensor fusion algorithms work in an air-to-air environment in three-dimensional space was much more difficult, Morley says.

“We spent about nine months beyond what we expected just to work out the kinks on that,” he says.

The F-35 programme is scheduled to start testing a fix for the sensor fusion problem in a few weeks, Bogdan says. But the Marines could declare the first F-35B unit operational before the fix is ready.

“The fixes we are getting ready to flight test for some of the deficiencies we found in our fusion algorithms and some of our pilot vehicle displays are actually being tested on our Block 3I software,” Bogdan says. “Once we complete that, we will go back and retrofit all the 2B airplanes with those fixes. We intend on taking that 3I software with the fixes to flight test around the last week of June. We’ll spend about 30 days flight testing those fixes, and if they appear to be good, then we will just leave those in 3I for the future airplanes and port them back into 2B.”

As the software is being fixed, the F-35 programme is finally preparing to enter a new phase. The long period of development and testing will begin to wind down in two years. Meanwhile, Lockheed’s factory has been stuck in a holding pattern for three years, delivering F-35s at an average pace of about three aircraft per month to US and international customers.

If the Pentagon’s budget proposals are cleared by Congress and international customers buy their expected share, F-35 deliveries could increase by about five-fold over the next five years. The Department of Defense is continuing to negotiate a block-buy deal for the next two years, but is already looking to negotiate a three-year block buy of more than 400 aircraft.

Bogdan first floated the idea of a multi-year, bulk acquisition of the F-35 at the Farnborough air show last July. More details of the proposal were released in March. The programme office issued a pre-solicitation notice for a proposal to buy as many as 477 F135 engines on a single contract covering a three-year period, with no spare engines included.

If Congress authorises the multi-year deal, Lockheed and its supply chain may be able to achieve the economies of scale required to drive the unit recurring flyaway price of the F-35A from $108 million a year ago to about $80 million in FY2019, as programme officials have promised. Although the programme has invested $170 million to fund cost-saving initiatives, Bogdan has said that four-fifths of F-35 cost reductions come from increasing the production rate to achieve economies of scale.

But Kendall’s staff will be watching the negotiations carefully. Multi-year acquisition deals are generally approved only when the contractor agrees to reduce unit costs by more than 10%, which in the case of the F-35 can amount to $8-10 million reductions each year of the deal.

“I’d like to see double-digit savings, not very different from what we try to do with a multi-year,” Kendall says.

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Source: Flight International