Page 151(The Bitter End)
rity forces either by helicopter or by waterborne means.
Saigon Rooftops-This entailed assembling evacuees for preliminary extraction at approximately one dozen locations throughout Saigon. Helicopters would then transport them to the DAO/Air America Complex for further processing and marshaling. Fireteam-sized elements were envisioned for rooftop security and to serve as landing zone control teams.
U.S. Embassy-With only one rooftop landing zone restricted to a single CH-46 or smaller aircraft, the Embassy was never seriously considered as a mass evacuation site. The maximum extraction total for this location was estimated at no more than 100 people. The possibility of using an additional landing zone existed, but only if a large tree and some lesser obstacles could be removed from the area adjacent to the courtyard parking lot.
Vung Tau-The largest of all the possible evacuation sites, Vung Tau, plagued the planners from the first day. Hundreds of thousands of refugees, as well as the remnants of the South Vietnamese Army and Marine Corps had retreated to the Vung Tau Peninsula by mid-April. Many had hopes of being sealifted from there to safe haven. For this reason, consideration was given to a MAB-sized amphibious landing to secure both the airfield and the port facilities in order to develop a major marshaling and evacuation center. The estimated size of the force necessary to accomplish this ranged from one battalion landing team to the entire brigade. To commit a brigade-sized force to the Vung Tau alternative meant more than just a temporary fix or an emergency evacuation. It meant a full-scale commitment of logistical and personnel assets. With the added confusion each new day brought, this complicated alternative became a planner's nightmare and more of an enigma than a solution. It truly offered more problems than it solved.19
The majority of the landing sites provided access only via helicopter and as a consequence most of the joint planning focused on making the brigade's helicopter flow plan (movement schedule) mesh with USSAG's operational plan. The forward extension of USSAG's Headquarters, the airborne battlefield command and control center, would control the helicopters in and out of the landing zone once they went "feet dry" (over land). Until that point they would be under the control of the Navy and thus the two schedules had to be integrated.
The coordinated flow schedule had to support a scheme of maneuver ashore that would include insertion of the landing force, emergency evacuation of the civilians, and extraction of the security force with enough inherent flexibility to encompass all of the potential sites and the use of any or all of the available flight decks. Additionally, the final schedule had to be one that could be controlled "feet dry" by the airborne controller and "feet wet" by the helicopter direction center (HDC) on the Okinawa. After achieving this, the planners faced another problem, clarification ofL-Hour. To the Marines it meant the landing time in the zone, while to the Air Force it signified mission launch time, The former definition was used in the evacuation from Cambodia. For this operation, L-Hour was defined as the time the first helicopter should touch down in the landing zone.20
Another matter of concern, the weather, represented a significant variable that the 9th MAB commander could ill afford to ignore. Predictions called for periods of inclement weather with ceilings of less than 1,000 feer and reduced visibility. Since the time of the operation was unpredictable, night operations also had to be included in the planning. The resultant scheme of maneuver anticipated performing the mission day or night, and under instrument conditions if necessary. There would be difficulties and operational limitations: no approved helicopter letdown (a tested and approved approach to a landing site for other than visual conditions), limited navigational aids, suspect air defense network, and a makeshift air control system. Even the threat of a tropical storm did not alter the MAB's plan or the timing of its release. This did not mean that higher headquarters was without reservations about the wisdom of attempting an evacuation at night or under instrument conditions. They had reservations, but General Carey believed that if weather conditions permitted takeoff, the Marine helicopter pilots could finish the job.
In evaluating aircraft availability, the staff closely monitored the daily reports and confidently noted that despite an extended period at sea, the Marine maintenance crews, with the support of the Navy supply system, had consistently attained high operational ready rates. Yet variances in the average cycle rate for helicopters in their round trips between ship and shore
Page 151(The Bitter End)