NEW : Air traffic controllers ' group says problem will be persistent throughout day . NEW : FAA has officials trying to pinpoint cause of computer system failure . ` ` I ' m frustrated . I have to be somewhere , '' delayed passenger says . Air system not compromised , FAA says .
NEW : Air traffic controllers ' group says problem will cause delays throughout day . NEW : FAA says officials working to pinpoint cause of computer system glitch . `` I 'm frustrated . I have to be somewhere , '' delayed passenger says . Air safety not compromised , FAA says .