In the beginning of 1963, Monkey Mountain faced two problems. The first, as has been seen, was the continuing effort to prove itself as a collector of unique VHF. The second, which started brewing in the early spring, involved the effort by NSA to collocate the AFSS mission at Danang, which included Monkey Mountain, with the new ASA site at Phu Bai. The reasoning provided by NSA for the collocation plan seems to have been driven mainly by an organizational desire to centralize all of the services at Phu Bai, the marines already having been ordered to move in.

The USAFSS command resisted the move for three reasons. First of all, the air force elements that needed the SIGINT support in case an air war developed were located at Danang. Second, it was considered that Danang was a much more easily defendable position in case of an overt attack from the DRV. The third reason was that the USAFSS considered the potential for VHF intercept to be as good as that from other sites. In fact, ASA tests at Danang had indicated that all intercept at Phu Bai was only marginally better.

Throughout the rest of 1963, AFSS and NSA contested the retention of the site at Danang. NSA, on occasion, questioned whether or not the VHF intercept was worth it: even the then deputy director, Dr. Louis Tordella, regarded the Monkey Mountain experiment a “complete bust.” This opinion was surprising, especially when considering [ — ] the mission, as well as the productive HF manual Morse and satisfactory HF radiotelephone collection.  Monkey Mountain began to bear fruit by June 1963, when it established consistent VHF intercept [ — ]

However, even with its initial intercept successes, Monkey Mountain’s status remained “temporary” for the rest of the year. For NSA, the problem with the site was that it did not fit into the overall plan for expansion in Southeast Asia. Phu Bai was seen as the major U.S. SIGINT complex in South Vietnam. [ — ] The director, NSA, General Gordon Blake, seemed uncertain about the status of the site. In August, after a high-level conference in the Pacific, he conceded that Danang could stay. Then in early October, NSA pushed for Monkey Mountain either to become an ASA site or to be resubordinated to the army. The army would resist this plan, claiming a shortage of funds.

The solution, which was arrived at more out of weariness with the bureaucratic arm wrestling than anything else, was to have the USAFSS go with an “austere” site at Danang that could gear up an expanded direct support mission when events warranted them. Some of the site’s funding was cut and about eighteen personnel were transferred out. The year 1963 would come to a close [ — ] still uncertain as to what was Danang’s future role in South Vietnam.

Surprisingly, civilian cryptologists arrived in South Vietnam almost on the heels of the ASA contingent, albeit in far fewer numbers. The use of civilians was dictated primarily by the operational need for technical support to military analysts at both ASA sites in the Philippines and in Saigon. The original arrangement called for the ASA detachment in-Saigon to perform intercept and some analysis. Meanwhile the analysts in the Philippines formed a special analytic support and reporting team to back up Saigon’s work. However, it was soon evident that neither site was prepared for the mission facing them. Partly, this was attributable to the slow receipt of the raw intercept from Tan Son Nhut; but the army analysts and collectors at Clark Air Base simply were not up to speed technically on the Viet Cong (VC) problem.  The short training sessions for selected ASA personnel at NSA HQ earlier in the year had not been successful in producing technically proficient analysts.

Featured image: Monkey Mountain, Danang AB, RVN

Source: Spartans in darkness: American SIGINT and the Indochina War, 1945-1975