 To avoid ambushes it turned off Highway 1 a few kilometers north of the city, traveled east cross-country, and swung around the rear of Mang Ca through the Trai Gate.Also on 7 February, the North Vietnamese tried to bring their own air support into the battle, sending four Vietnam People's Air Force Il-14 transport aircraft from an airfield near Hanoi.Two of the aircraft carrying explosives, antitank ammunition and field telephone cables managed to find an opening in the cloud layer about north of Huế.