Opinion: F-35B Vertical Landings In Doubt For U.K.

Opinion: F-35B Vertical Landings In Doubt For U.K.

Air show plans highlight F-35B runway issues

May 26, 2014 Bill Sweetman | Aviation Week & Space Technology ertisement

U.S. Marine Corps aviation boss Brig. Gen. Matthew Glavy has said there are no plans for the F-35B to perform VLs in the U.K., because the program staff has not finished testing the matting that is needed to protect the runway from exhaust heat. (The program office, Marines and Lockheed Martin did not return emails about any part of this story.) It may sound like a simple issue, but it pops the lids off two cans of worms: the program’s relationship with the truth, and the operational utility of VL.

In December 2009, the Naval Facilities Engineering Command (Navfac) issued specifications for contractors bidding on JSF construction work. The main engine exhaust, the engineers said, was hot and energetic enough to have a 50% chance of spalling concrete on the first VL. “Spalling” occurs when water in the concrete boils faster than it can escape, and steam blows flakes away from the surface.

Lockheed Martin was dismissive. The specifications were out of date and based on worst-case assessments, the company said, and tests in January 2010 showed that “the difference between F‑35B exhaust temperature and that of the AV-8B is very small, and is not anticipated to require any significant Conops [concept of operations] changes.”

Navfac ignored Lockheed Martin and commissioned high-temperature-concrete VL pads at four sites. At the Navy’s Patuxent River, Md., flight-test center, F-35Bs perform VLs on a pad of AM-2 aluminum matting, protecting the concrete from heat and blast. Why didn’t the January 2010 tests result in a change to the specifications? How were those tests performed? The Navy has referred those questions to Lockheed Martin, which has repeatedly failed to answer them.

This isn’t the only instance where Lockheed Martin has tried to shoot the messenger on the basis of weak facts.  When a Rand Corp. report last year concluded that the JSF will cost more than three single-service programs, Lockheed Martin accused Rand of using “outdated data” but founded that criticism on numbers that were not in the report.

After the fiscal 2011 Selected Acquisition Report showed the F-35A cost per flight hour to be 40% higher than the F-16’s, program leaders asserted that the Pentagon’s accountants had misinterpreted their own numbers. Two reports later, the numbers have barely budged.

The bigger issue is that the Pentagon bought the F-35B for two reasons: it can land on an LHA/LHD-class amphibious warfare ship, and it can operate from an improvised forward operating location (FOL), created around a 3,000-ft. runway. The capabilities are complementary. Without an FOL, the amphibious force is limited to six fighters per LHA (unless essential helicopters are off-loaded). But a short runway is of little value unless you can use it twice.

And what Navfac calls “standard airfield concrete” is military-grade, made with aggregate and Portland cement. Many runways are built with asphaltic concrete—aggregate in a bitumen binder—which softens and melts under heat.

The Marines could use AM-2 landing pads. But AM-2 is not a friend to the agility that justifies the F-35B over other forms of expeditionary airpower. An Air Force study calls it “slow to install, difficult to repair, [with] very poor air-transport-ability characteristics.” A single 100 X 100-ft. VL pad weighs around 30 tons and comprises 400 pieces, each individually installed by two people.

Rolling or creeping vertical landings can spread the heat load over a greater area. But there is no sign that they have been tested on concrete, asphalt or AM-2 over asphalt. What about multiple, close-together landings? Will hot asphalt debris stay off the fighter’s low-observable skin? 

Nobody seems willing to say when such tests will be conducted—which is odd, because we conduct flight tests to prove an aircraft can meet requirements. How was the requirement for the F-35B to VL on a non-standard runway framed? Indeed, was that requirement formally defined at all? 

At least $21 billion of the JSF’s research and development bill—including the F135 engine and the crash weight-reduction program of 2004 as well as the powered-lift system—is directly attributable to the F-35B, which also has the highest unit cost of any military aircraft in production. The design compromises in the F-35B have added weight, drag and cost to the F-35A and F-35C. It would be nice to know that—air shows aside—it will deliver some of its promised operational utility. 

Posters comments:  It is being proposed to have the F-35B participate in the ceremonies surrounding the newest aircraft carrier in the UK Navy.