Technical and performance problems with the F-35 Joint Strike Fighter appear to be more numerous and more serious than anyone in the Department of Defense has been willing to concede publicly, according to a leaked Pentagon report obtained by the Fort Worth Star-Telegram.

The internal report marked "For Official Use Only" is written in carefully couched language, but clearly sounds alarms that some very large, troubling and costly to resolve technological and performance issues lie ahead for the already troubled and massively over budget F-35.

The Project on Government Oversight has posted a copy of the report on its web site.

The report prepared by a team of senior Pentagon technical, engineering and test experts found that “unsatisfactory progress” had been made in development and testing of the F-35 in nearly all of the air combat roles that it is designed to perform.

In ground attack roles the report cites concerns about “mission capability and survivability” and “certain classified survivability issues."

Although most of the really challenging flight testing of the F-35 in high speed, air combat regimes has yet to be performed, the Pentagon and military officials overseeing testing “expressed significant concerns with aircraft performance characteristics.”

The “Quick Look Review” report, 50-plus pages including numerous charts, illustrations and detailed projections, was prepared just since mid-October by a team headed by five senior Pentagon officials with expertise in weapons evaluation testing and engineering.

It was requested by Frank Kendall, acting undersecretary of defense for weapons acquisition and development. Kendall asked for the report to assess the state of F-35 development so defense officials could decide whether and how many planes they should agree to buy while development was still under way.

The report essentially concludes that highly sophisticated design and modeling technology has failed in predicting and preventing problems with the design, production and performance of the aircraft and its critical combat systems.

In no case does the report state that any of the problems cannot be overcome or that the F-35 will be unable fulfill its intended missions, but it does strongly suggest the worst of the problems may not yet be known and that the fixes will take years and vast new sums of money.

The report authors say as a result of the combined issues the Pentagon should go very slowly in buying more jets.

To read the complete article, visit www.star-telegram.com.