Prelude to Operation ENDSWEEP
By AD1 Barry W. Marple USN Retired
Imperceptibly at first, the lull in the air war over North Vietnam came to a progressive end during the last two months of 1971 and the first quarter of 1972. The North Vietnamese, seeking to hide preparations for their new offensive against South Vietnam, began firing more frequently at reconnaissance aircraft and their escorts flying "Blue Tree" missions, and the U.S. responded with more and heavier protective reaction strikes.
As increased evidence of an incipient North Vietnamese offensive was being gathered and as the Paris Peace Talks were stalemated, the United States broke off the negotiations on 23 March 1972. Furthermore, not wanting to be caught unprepared as they had been four years earlier when the Communists launched their 1968 Tet Offensive, South Vietnamese and American forces went on full alert. Thus, when three North Vietnamese Army (NVA) divisions, including tanks and heavy artillery supported by a large number of shoulder-fired SA-7 surface-to-air missiles, crossed into South Vietnam on 30 March to initiate the 1972 Spring Offensive, the defenders were ready on the ground and a schedule to bring air reinforcements had been detailed. For Task Force 77 (TF 77), this meant that its aircraft were immediately thrown into the battle to provide much needed air support to the South Vietnamese defenders (680 sorties were flown during the first week of April as opposed to an average of sixty-six weekly sorties during the previous quarter) while plans were made for a new air offensive against the North.
Already intense, the pace of activity increased even further in May as the scope of U.S. air operations over the North was broadcast with the launching of Operation Pocket Money and Linebacker. On 10 May, restrictions on sustained air operations above the 20th parallel were lifted as Operation Freedom Train gave place to Linebacker 1. On 18 May, bombing of several industrial targets in the Haiphong restricted zone were first authorized. From the Naval Aviation point of view, however, the most significant event was Pocket Money, the mining campaign against all major North Vietnamese harbors and waterways, which was announced by President Nixon on 9 May. Simultaneously with this announcement, in which a three-day warning was given to enable Soviet and neutral merchant vessels to leave North Vietnamese waters before the mines were activated. A-6As and A-7Es from CVW-15 sowed the first sixty-six mines (with 72-hour arming devices) in the outter approaches of Haiphong Harbor. Two days later, six other harbors were mined and soon thereafter mining operations were extended to include most coastal and inland waterways. Eventually, over an eight-month period, more than 11,000 mines were planted, effectively blockading maritime transport to and from North Vietnam.
At last, on 23 January 1973, the hollow but grandiloquently titled Agreement on Ending the War and Restoring the Peace in Vietnam was signed in Paris. In accordance with the Agreement, preparations for the return of the prisoners of war (Operation Homecoming) were made, the removal of mines from Haiphong Harbor (Operation ENDSWEEP) was scheduled to commence within a month, and air operations over both North and South Vietnam were to end. Offensive operations against the North had been suspended on 15 January, and all other air activities over North Vietnam ceased on 23 January. The last sorties over South Vietnam were flown on 27 January but not before two more aircraft were lost. The pilot and bombardier / navigator of a VA-35 A-6A from USS America were recovered by a Navy helicopter on 24 January, thus becoming the last of 161 Naval Aviators rescued by Navy SAR helicopters. Cdr. H.H. Hall and LCdr. P.A. Kienzler, the pilot and RIO of a VF-173 F-4J from USS Enterprise, the last Navy aircraft to be lost in combat during the Southeast Asia War were taken prisoner of war after ejecting on 27 January but were soon released.
Planning for Operation ENDSWEEP had begun before the conclusion of the Paris Peace Talks as, knowing that the mining of Haiphong was having telling effects on the North Vietnamese economy, the U.S. negotiating team had used an offer of removing the mines as a bargaining point to obtain from Hanoi the release of American prisoners of war. Accordingly, as soon as negotiations were concluded, the Navy set up Task Force 78 (TF 78) to conduct minesweeping operations in North Vietnamese waters using surface minesweepers and specially configured CH-53 helicopters from one Navy and two Marine Corp squadrons (HM-12, HMK-463, and HMM-165) which operated from the deck of two amphibious assault ships, USS Inchon (LPH-12) and USS New Orleans (LPH-11). Mine removal operations began on 6 February and ended on 27 July 1973. During that time, USS Coral Sea, USS Enterprise, USS Oriskany, and USS Ranger were sent at various times, to the Mine Logistics Carrier Station to provide air cover for TF 78. However, the most important contribution made to Naval Aviators during Operation ENDSWEEP was that made by the crews from the three helicopter squadrons which flew over 1100 hours on mine removal duty.
On 20 June 1973, five-weeks before Operation ENDSWEEP was completed, Congress ordered the cessation of all combat operations in Southeast Asia on 15 August. Although the congressional action effectively ended U.S. participation in the Southeast Asia War, fighting continued in Vietnam and Cambodia.
For U.S. personnel, the relief brought by this unconclussive end to their fighting was bittersweet as nothing could be shown for the sacrifices and suffering of so many. While serving with TF 77, three hundred and seventy-seven Naval Aviators had been killed in action, 144 of the 179 aircrewmen known to have been taken prisoner of war were returned by the North Vietnamese, and at least 99 others were still reported as missing in action.
Last revised on 25 December, 1999 © Airborne Mine Countermeasures Association, Virginia Beach, Virginia. Webmaster - Barry Marple Virginia Beach, VA. Domain name property of Barry Marple. All rights reserved.
