A software glitch regarding the change in longitude from W179.99 degrees to E180 forced 12 United States Air Force F-22A Raptor stealth fighters to cancel their first overseas flight. The jets were flying from Hawaii to Japan when they were forced to turn back using only visual contact with their tankers after the onboard navigation, communications and fuel systems crashed as the planes crossed the International Date Line. Because of "operational security reasons" the USAF refused to specify the cause of the issue saying only that the aircraft "experienced a software problem involving the navigation system en route from Hickam to Kadena". The $125m planes, the most expensive fighters ever built, returned safely, but the situation may have been disastrous had they not been with their tankers or had the weather not been on their side.