Page 147-148 ABOVE TOP SECRET (Timothy Good)
On the night of 4 September 1957 a flight of four US-built F-84 Thunderjets took off from Ota Air Base, Portugal, on a routine practice navigation mission. It was a clear night with an almost full moon, and the air to ground visibility reported in flight was well over fifty statute miles. The pilots were Captain Jose Lemos Ferreira, the flight commander, Sergeant Alberto Gomes Covas, Sergeant Manuel Neves Marcelino and Sergeant Salvador Alberto Oliveira. Captain Ferreira takes up the story.
After we reached Granada, at 2006 hours, and started a port turn to change course to Portalegre I noticed on my left and above the horizon a very unusual source of light . . . after three or four minutes I decided to report it to the other pilots. At that time the pilot flying on my right wing told me he had already noticed it. The other two pilots flying on my left wing had not yet seen it. Together we started exchanging comments over the radio about our discovery and we tried several solutions but none seemed to be a reasonable explanation for the thing we were observing at the moment. The thing looked like a very bright star unusually big and scintillating, with a colored nucleus which changed color constantly, going from deep green to blue to passing through yellowish and reddish colorations.
The pilots dismissed the possibility that the object could have been either Venus or another planet or star, or a balloon or aircraft. Captain Ferreira continued:
All of a sudden the thing grew very rapidly, assuming five or six times its initial volume, becoming quite a spectacle to see . . . [then] fast as it had grown, [it] decided to shrink, almost disappearing on the horizon, becoming a just visible, small, yellow point. These expansions and contractions happened several times, but without becoming periodic and always having a pause, longer or shorter, before modifying volume. The relative position between us and the thing was still the same, that is about 40° on our left, and we could not determine if the changing dimensions were due to very fast approaches and retreats on the same vector or if the modifying took place stationary. . . . After about seven or eight minutes of this the thing had been gradually getting down below the horizon and dislocated itself for a position about 90° to our left. ... At 2038 hours I decided to abandon the mission and to make a port turn in the general direction of Coruche since nobody was paying any attention to the exercise. We turned about 50° to port but still the thing maintained its position of 90° to our left which could not be possible with a stationary object.
By now the phenomenon was well below our level of 25,000 feet and apparently quite near, presenting a bright red and looking like a curved shell of beans at an arm's length. After several minutes on our new course we discovered a small circle of yellow light apparently coming out of the thing and before our surprise elapsed we detected three other identical circles on the right of the thing. The whole was moving with their relative positions changing constantly and sometimes very rapidly. Still we could not estimate the distance between us and them, although they were below us and apparently very near. In any case the big "thing" looked ten to fifteen times greater than the yellow circles and apparently was the director of operations since the others were moving around it.
As we were near Coruche the "big thing" suddenly and very rapidly made what looked like a dive, followed up by a climb in our direction. Then everybody went wild and almost broke formation in the process of crossing over and ahead of the UFO. We were all very excited and I had a hard time to calm things down. As soon as we crossed over everything disappeared in a few seconds and later we landed without further incident. Since the first moment we detected the UFO to the final show a registered time of forty minutes had elapsed, and during it we had ample opportunity to verify every possible explanation for the phenomenon. We got no conclusions, except that after this do not give us the old routine of Venus, balloons, aircraft and the like which has been given as a general panacea for almost every case of UFOs. [Emphasis added]
At the same time that the pilots had their encounter, the Coimbra Meteorological Observatory registered extraordinary localized variations in the earth's magnetic field, as proven by charts at that establishment. 29*
* Ferreira, Captain Jose Lemos, FSR, Vol. 4, No.3, 1958, pp.2-3)