Hostage-rescue mission's weak link: too-tight security? Picture 1, Aircraft carrier USS Nimitz, UPI photo; Picture 2, Defense Secretary Brown, UPI photo; Picture 3, Iranians on bus detained, UPI - Sketch by Ida Libby Dengrove; Picture 4, Raid commander Beckwith, UPI photo; Picture 5, Engine of burned C-130, UPI photo

The need for utmost secrecy may well have sabotaged President Carter's daring attempt to free the US hostages in Tehran, according to the report of a special panel set up to investigate the mission's failure.

Too small a helicopter force and insufficient weather reconnaissance were two primary factors cited by the six-man review group headed by retired Adm. James L. Holloway III. The report was released over the weekend. And, the report points out, the chief reason for both deficiences was the desire to avoid tipping off the Iranians that something was up.

"A larger helicopter force and better provisions for weather contingencies would have increased the probability of mission success," declares the report issued by the six-man group charged by the US Joint Chiefs of Staff with scrutinizing the abortive April 25 raid to free the 52 hostages, now in their 296th day of captivity.

As planning for the rescue progressed, the number of helicopters thought necessary for the mission apparently grew from four, to six, to seven, and eventually to eight. But, as it transpired, eight were not enough.

One of the RD-53D Sea Stallions chosen for the task turned back to the carrier USS Nimitz with a compass malfunction, and the entire operation was aborted when two others later suffered mechanical breakdowns.

The report declares that the decision to use eight helicopters was based "on the collective professional judgment of highly experienced helicopter pilots participating in rescue mission planning." It adds, moreover, that "a risk analysis based on fleetwide RH-53D statistical data for an 18-month period from 1 July 1978, to 31 December, 1979, seemed to support the planners' conclusion that eight RH-53D helicopters abroad Nimitz provided an acceptable degree of risk."

The need for secrecy "influenced the planners' rationale, driving them to seek minimum practical force levels," it adds.

The review group asserts that but for the requirements of secrecy there were no operational or logistical factors to prevent 10 helicopters taking part in the raid.

But supplementing the helicopter force would have meant abandoning more of the machines in Iran, besides reducing contingency fuel at Desert One (the initial staging area in Iran) and generally increasing the risk of discovery, the report states.

Stepping gingerly through a minefield of contingencies, the report's authors declare, on one hand, that it is "too simplistic" to suggest that more helicopters would have reduced the chances of the raid failing, while, on the other, asserting that "an increase in the helicopter force was warranted."

"If you asked me today were eight helicopters adequate, I'd really feel pretty dumb standing up here and saying yes," declared Admiral Holloway, a former Chief of Naval Operations, at Saturday's news conference called to release the report. On the much-debated question of helicopter maintenance, he declared that the condition of the Sea Stallions was "superior -- that is, better than excellent and really just about as good as we had any right to expect, both in performance and on the basis of inspections."

The report makes clear that the helicopter and C-130 pilots were surprised by the suspended dust they encountered. They had apparently not been apprised of the phenomenon. "The weather forecast for the night of April 24 did not predict reduced visibility over extended distances of the helicopter route," the report declares. "Uninformed and unprepared to cope with the extremely low visibilities encountered, the leader paused, the [helicopter] flight became separated, helicopter No. 5 aborted, and all the helicopters reaching Desert One were appreciably late."

The review panel suggests that a weather reconnaissance C-130 could have flown the route the helicopters were to take, thereby alerting mission chiefs to the dust pall and giving them the opportunity to wait for more favorable conditions. But the group discovered that such a flight was not staged for fear of attracting ground watchers who might then have observed the later helicopter flight.

Indeed, considerations of what the military all OPSEC (operations security) appear to have prevented pilots having any contact with mission meteorologists.

Moreover, the helicopter pilots were only prepared for navigation using night-vision goggles. "Consideration, we thought, should have been given to conducting the operation under instrument meteorological condition," said Admiral Holloway.

The report also declares that:

* Command and control were excellent at the upper echelons but "more tenuous and fragile" at intermediate levels.

* Mission preparation was adequate except for the lack of a comprehensive, full-scale training exercise during which command and control weaknesses "probably would have . . . been ironed out."

* The siting of Desert One near a road "probably represented a higher risk" than imagined.

While by no means declaring that the rescue bid strangled in its own security , the Holloway report does observe that "many things, which in the opinion of the review group could have been done to enhance mission success, were not done because of strict OPSEC considerations. . . . The review group considers that most of these alternatives could have been incorporated without an adverse OPSEC impact."

Admiral Holloway declared: "We spent no time on the things that went right, and more than 95 percent of what happened went right. We zeroed in on what went wrong so that hopefully steps could be taken so that those things would not happen if we had to do it again."