00900cam a2200253Ia 4500011413173MiAaHDL20141009010000.0m d cr bn ---auaua890621s1989 dcu f00010 eng dGAO/IMTEC-89-39sdr-uiuc1527490sdr-ucbk.b116706296AME-0265(OCoLC)19906902CBTCBTJCR0546-D (MF)GA 1.13:IMTEC-89-39United States.General Accounting Office.Air traffic control :voice communications system continues to encounter difficulties : report to Congressional requesters.Washington, D.C. :U.S. General Accounting Office,[1989]15 p. ;28 cm."B-234691"--P. 1."June 1989."Cover title.Mode of access: Internet.Switching circuitsAir traffic controlCommunication systems.01141317320020415162202.020141009010000.020141112160514.02024-12-30T19:06:07Z2024-12-30T18:30:02ZSDR-UIUCUNKNOWNloader.pl-003-020BKsdr-uiuc1527490uiugSDRUIUCuiug.30112033968154UIU1527490UIUUIUC20241230googleuiug.301120339681541989pdbibUS fed docUCUCBK20240624googleuc1.c1013637871989pdbibUS fed doc