Originally posted by Maus92
Some not so good news about the Charlie: Testing was halted back in November after a "small crack" was found in the titanium wing spar, which was downplayed at the time by JPO spokesperson Joe DellaVedova, "Such discoveries are expected during a developmental test program." Note that the JPO was more or less forced to respond to press reports about the cracks - the JPO had not released news of the casualty publicly. Testing resumed in February after repairs, but was halted 3 days later after strain gauges detected further cracking.
Interesting problem, but may not necessarily be a design problem, could be a material processing problem. Manufacturing titanium components can be tricky, whether they are cast or forged. Both processes expose the components being produced to elevated temperatures that form a brittle layer called alpha case. The alpha case must be removed to prevent cracks from developing in service. The usual method of removal is chem-milling the component. But if not done properly, one of two things can result, the alpha case isn't totally removed or hydrogen is introduced from the bath chemicals into the titanium resulting in subsequent hydrogen embrittlement and cracking in service. So I am sure it will be witch hunt to identify the cause and spars affected if it isn't a basic design problem...