accepting its next FB-111A until 23 June 1969. On 8 October 1969, the 7th FB-111A entered service with the 4007th Squadron. Even though the FB-111A was officially declared operational, it had yet to reach the combat forces. After reaching operational capability, the 4007th relocated to Plattsburgh Air Force Base, New York and became part of the 380th Strategic Aerospace Wing, with its personnel and equipment reassigned to the reactivated 9th Bombardment Squadron, which became the first SAC operational bomb squadron to fly the FB-111A. The crash of an F-111 at Nellis Air Force Base in December 1969 caused the grounding of all F and FB-111As. The group flew Lockheed T-33 T-Bird trainers until FB-111 flying activities resumed in June 1970 and delivery of resumed on 25 July 1970. By the end of September, the unit possessed twenty FB-111A aircraft. In January 1971, the FB-111A achieved initial operational capability with the 509th Bombardment Wing (393d and 715th Squadrons) at Pease Air Force Base, New Hampshire. When inactivated on 31 December 1971, the 340th possessed 38 FB-111As, which were transferred to Plattsburgh and Pease. Linebacker II and subsequent Cold War years With the FB-111 program ended at Carswell, the squadron returned to flying the B-52D Stratofortress, some in support of alert exercises and some in support of conventional bombing in Vietnam. In early 1972, the unit returned to Andersen Air Force Base once again in support of Operation Arc Light. This time North Vietnam was the target. In October 1972, peace talks with the Vietnamese had reached an impasse. That, combined with increased enemy ground activity, was to see the 9th take part in a historical mission known as Linebacker II. Bombing targets in the Hanoi and Haiphong regions of North Vietnam, that mission helped bring the Vietnamese Communists back to the peace talks in Paris and a cease fire was signed on 28 January 1973. The 9th returned to Carswell in September 1973 and returned to their peacetime missions. With the end of the Vietnam War, the 9th Bombardment Squadron remained at Carswell learning and training for their military mission. In late 1982 its B-52D models were retired and it received B-52H models from the inactivating 37th Bombardment Squadron at Ellsworth Air Force Base, South Dakota. With the B-52H's it stood on nuclear alert. Its B-52H bombers were on nuclear alert during Operation Desert Shield in 1991 and the squadron was