Wing 112th/124th Liaison squadron: O-1A, U-17A 514th/518th Fighter Squadron: A-1H 43d Tactical Wing 221st/223d/231st/245th/251st Helicopter Squadrons: UH-1H 237th Helicopter Squadron: CH-47A Det E 259th Helicopter Squadron: UH-1H (Medevac) 63d Tactical Wing 522nd/536th/540th/544th Fighter Squadrons: F-5A/B/C RF-5A On 10 August 25 rockets hit the base with 7 hitting the F-5A storage area, slightly damaging a few planes. Capture of Bien Hoa Air Base In early April 1975 the PAVN were closing in on the ARVN's last defensive line before Saigon. The town of Xuân Lộc stood at a strategic crossroads 70 km east of Bien Hoa and was defended by the ARVN 18th Division. On 9 April the PAVN 4th Corps comprising 3 Divisions attacked Xuân Lộc. The 18th Division defended the town tenaciously with air support from the RVNAF 3rd Division at Bien Hoa and the 5th Division at Tan Son Nhut AB. On the morning of 15 April a PAVN sapper squad penetrated the base blowing up an ammunition dump and 4 PAVN 130mm field guns began shelling the base, later joined by 122mm rocket batteries which cratered the runways and severely restricted flight operations. By 19 April Xuân Lộc was completely surrounded and the ARVN command ordered its forces there to withdraw to defend Saigon. On 20 April after launching a diversionary attack east of Xuân Lộc, the ARVN units in the town broke out and on 21 April the PAVN captured the town. On 25 April the 3rd Armored Regiment which was fighting at the town of Hung Nghia was ordered to withdraw west along Route 1 to defend Bien Hoa. The ARVN formed a new defensive line east of Bien Hoa at the town of Trảng Bom which was defended by the remnants of the 18th Division, the 468th Marine Brigade and the reconstituted 258th Marine Brigade, which had disgraced itself during the fall of Da Nang. At 04:00 on 27 April the 341st Division attacked Trang Bom, the initial attack was repulsed but by 08:00 attacks on the flanks broke through and the town was captured with the 18th Division suffering heavy casualties in their retreat. The PAVN then advanced to the town of Hố Nai (now Tân Hòa), which was held by the Marines. Hố Nai was defended by the 6th Marine Battalion, an M48 tank from the 3rd Armored and Popular Forces. Following an artillery barrage the PAVN attacked Hố Nai, but were