0000898430-01-000842 S-4/A 2 20010305 NNG INC 0001133421 3812 DE 1231 S-4/A 33 333-54800 1561505 1840 CENTURY PK E C/O NORTHROP GRUMMAN CORP LOS ANGELES CA 90067 3105536262 1840 CENTURY PARK EAST C/O NORTHROP GRUMMAN CORP LOS ANGELES CA 90067 S-4/A 1 0001.txt FORM S-4 AMENDMENT #1 EX-5.1 2 0002.txt OPINION OF JOHN H. MULLAN