This is one I had missed, probably because  it was selected by the Condon Committee and because the explanations given appeared to indicate it wasn't that good a case. It's a good thing I read about it in Ann Druffel's "Firestorm". ("FIRESTORM: DR. JAMES E. McDONALD's FIGHT FOR UFO SCIENCE")

According to her report (page 399) the incident began when Vandenberg AFB radar detected a very large stationary object some miles over the Pacific off the Northern California coast. Later, radar detected numerous small, but strong, targets traveling eastward in irregular flight. The location and time of Case #35 was listed in the Condon Report as "South Pacific, Fall 1967."

In April, McDonald had spoken before the AIAA section at Vandenberg AFB, and while there studied on-site the details of Case 35. An original, large object had been viewed for 45 minutes by a missile-range official at elevation 10-15° in the west-northwest. Unable to identify it, the of­ficial called another range official, who viewed it through binoculars. The large object was elliptical and the apparent size of "a large thumbtack." Although it had red and green lights similar to aircraft, it was stationary for 45 minutes and was "fuzzy, like a spinning top."

Range Control Operations at Vandenberg AFB was alerted; they confirmed that the object was several miles out over the ocean at about 10,000' altitude. When missile radars were asked to look for it on a search mode, they detected numerous smaller objects in that area. They traveled at varying speeds, up to 80 knots. Several additional visual sightings were detected to the east and north, over land. The Condon Report had "identified" the smaller objects as birds, AP (anomalous radar propagation) and perhaps a meteor or two, and the large object as a mirage of a ship at sea. According to the Condon Re­port, all the "misidentifications" had been caused by a "remarkable inversion layer" which permitted optical mirages, scintillation, and AP, in spite of the fact that many of the radar lock-ons indicated objects much larger than birds.

McDonald had earlier been informed by a Vandenberg official that his had been queried by radio from the NWC at China Lake. NWC wished to ascertain whether or not, at midday on October 6, 1967, any aircraft from Vandenberg might have been flying in the NWC area at China Lake. VAFB responded "negative." This inquiry was not mentioned in Condon's "Case 35."

Druffel: "When he learned of the UFO incident at China Lake, which lies inland directly east of Vandenberg AFB, McDonald had established contact with Lyman van Buskirk of the NWC. He asked if van Buskirk could inquire about the naval aviator's sighting, which had occurred a few hours before the Vandenberg radar-visual incident. The fact that the China Lake sighting occurred some hours before the Vandenberg sightings did not trouble him particularly because he was aware of the 'carrier craft' concept in the UFO literature from Jacques Vallee and other reliable researchers and considered such sightings, when reported by credible observers, as valid. 'Carrier craft' were large UFOs from which smaller UFOs departed and returned over a period of hours."

The Vandenberg incidents, therefore, possibly represented a "carrier craft" releasing numbers of smaller UFOs. Large UFOs like this had appeared off the California coast from time to time, reportedly hovering for hours some miles at sea. If the Vandenberg main object was a "carrier craft," the Vandenberg reports and the China Lake aviator sighting could possibly be linked. In McDonald's files, no indication had been found that he managed to track down the NWC aviator sighting.