A K2 Airways Boeing 737 cargo plane with five crew members disappears after reporting navigation problems and then rapidly descending while flying from Sharjah, United Arab Emirates, to Karachi.Radar and flight data show a sharp course change and erratic altitude swings before the aircraft loses radar and radio contact about 155 nautical miles west of Karachi.The Pakistan Civil Aviation Authority says navy and air force units join a coordinated search-and-rescue operation in the Arabian Sea while K2 Airways confirms it is cooperating and Boeing does not comment.The 27-year-old
Boeing 737-400 was built for
Aeroflot in 1999 and converted to cargo use in 2012, it was the only plane operated by
K2 Airways and investigators say recovery of wreckage and flight recorders is essential to determine a cause.