The U.S. Department of Defense’s top officer on the F-35, Adm. David Zenlet, has recommended that deliveries of the aircraft be delayed because of the discovery of cracks and “hot spots” during fatigue testing and analysis (Gloria Galloway, “Tories face fresh hurdle with U.S. call to slow F-35 jet production,” Globe and Mail, 2 December 2011). 

Zenlet said the Pentagon was surprised at the extent of the changes required and the cost of making the changes:

“Most of them are little ones,” he said. “But when you bundle them all up and package them, and look at where they are in the airplane and how hard they are to get at after you buy the jet, the cost burden of that is what sucks the wind out of your lungs.” […]

“I believe it’s wise to sort of temper production for a while here, until we get some of these heavy years of learning under our belt and get that managed right,” he said.

The proposal to slow production marks another setback in the continually worsening timeline that has characterized the F-35’s development. There are already concerns about the real price of procurement, the degree of commitment of the U.S. and other allies to the aircraft, and several technological issues.