Sixteen of the 21 stealth bombers housed at Whiteman Air Force Base in West Central Missouri have developed cracks, but the base commander says the cracks should not ground any aircraft. General Tony Przybyzlawski says this sort of problem is common for many aircraft. Przysbyzlawski says the cracks do not result from increased stress due to the unusually long missions to Afghanistan. One bombing mission last October took 44 hours of continuous flight.