F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds

"Tires that wear out too soon are adding to the troubles facing Lockheed Martin Corp. (LMT)’s F-35, the Pentagon’s costliest weapons system.

Landing-gear tires made by Dunlop Aircraft Tyres Ltd. for the Marine Corps version of the fighter have “been experiencing an unacceptable wear rate when operating as a conventional aircraft,” according to Joe DellaVedova, spokesman for the Defense Department’s F-35 program office.

He said the tire, which costs about $1,500 apiece, demonstrates “adequate wear” when the aircraft performs short takeoffs and vertical landings intended for amphibious warfare vessels and improvised runways....

...The Pentagon is working with Lockheed Martin and Birmingham, U.K.-based Dunlop Tyres on a new design for the landing-gear tires that will be introduced next year, DellaVedova said in an e-mailed statement. In the meantime, Dunlop has provided a tire that’s “improved but still unacceptable,” he said.

‘Poor Design’
Michael Gilmore, the Defense Department’s director of operational test and evaluation, said the Dunlop tires are “wearing more quickly than expected” because of a “poor design,” according to a statement from spokeswoman Jennifer Elzea.

John Butters, a spokesman for Dunlop Tyres, said in an e-mailed statement that the initial tires “are experiencing high wear rates” and the interim model has “better tread wear.” The company says on its website that it makes “world class aircraft” tires “and nothing else.”

The Marine Corps model of the F-35 “faces a unique and challenging operational environment” demanding a tire “that can operate without damaging the landing surface,” Butters said....

...DellaVedova said that tires made by Michelin & Cie (ML) and Goodyear Tire & Rubber Co. for the Air Force and Navy carrier versions, while running down sooner “than originally desired, are currently averaging adequate wear rates.”

Military personnel at flight test centers and training locations “discovered that the tires were wearing out too quickly or becoming too thin,” Gilmore said.

Goodyear spokesman Scott Baughman said in an e-mailed statement that the company “works closely with its customers to meet tire specifications.” Michelin North America spokesman Brian Remsberg said in an e-mailed statement that “we have not received any complaints or requests for tire redesign.”"

"...The general cited problems with aircraft tires, especially on the Marine Corps' F-35B short-takeoff-and-vertical-landing variant of the aircraft, as one example of a "bad actor."

Those tires must be able to support vertical landings, accomplished by designing the tires to collapse somewhat upon impact with the ground. That quality is technically known as "float." On the other hand, the F-35B tires need to be capable of taking off conventionally, which demands durability. Those two characteristics, float and durability, are at odds with one another.

"Wouldn't you know, float and durability are on the opposite ends of the spectrum when it comes to designing a tire," he said...."

neptune wrote:Why can't they use the AF tires when CTOL training (EGLIN) and STOVL tires, if and when they progress to advanced training at Yuma? Seems like an OPS issue (mission specific) that is unique to training; after all how many sets of tires does an F-16 burn during an operational year? I know all of us with our vast experience of Vertical Landing will be offering the technical/ engineering details needed to refine the existing designs! Who would have thunk-it!

maus92 wrote:Could it be that the Dunlop tire design was optimized for STOVL ops, and it turning out that most operations are, and will be, in CTOL mode? And was the Dunlop tire ever redesigned to meet certain weight goals?