It is advisable to clarify that are considered as aeronautical cases those that were observed from aircrafts. This chapter describes five significant cases arisen in various continents and which were the object of an inquiry on behalf of the authorities of the concerned countries. In four cases objects were discovered at the same moment visually and by radar. In the fifth they were observed by numerous independent witnesses.

The plane RB-47 in the United States ( July 17, 1957)

This case, which appears in the report Condon as " not identified ", was very quoted and studied for 40 years. The physicist James Mac Donald published the results of his inquiry in 1971 in the review Astronautics and Aeronautics. Philippe Klass, the aforesaid journalist, tried then hard to give, in 1976 , a commonplace interpretation of the facts, very questionable from the beginning. This interpretation was refuted for the main part the end of 1997, in the term of a detailed inquiry, contained in a report of the researcher in aerospace techniques Brad Sparks.

We summarize here the important sequences of the case, which show a not identified brilliant flying object discovered of night, not only in the sight and in the radar, but also by broadcasts of pulsed microwaves resulting from its direction.

RB-47 was a bomber the hold of which with bombs had been fitted out to receive three officers arranging each of the means allowing to discover the emissions of radar on the ground, and to clarify their direction in azimuth, but neither their distance nor the nature of the signals. In the zone of the centre-South of the United States, where the plane made this day a flight of entrainement, numerous radar tracking stations emitted signals the frequencies of which were nearby of 3000 MHz and the impulses of a duration of 1 microsecond succeeding one another every 600 microseconds. These radars swept the horizon four times per minute.
Three other officers (pilot, co-pilot, navigator) were in the cockpit and, therefore, could see outside of the plane. The six officers, interrogated by Mac Donald in 1969, told that :

- The first incident occurred, probably at about 9h 30 (3h 30 at local time), over Mississipi, while the plane, the stimulant of the Gulf of Mexico northward, approached the coast little east of the delta of Mississipi, by flying from Mach 0,75. The captain Mac Clure discovered on his screen a spotlight corresponding to a source of pulsed microwaves situated behind and to the right of RB-47 ( in direction " 5 hours "), which exceeded quickly the plane and turned around him to leave on his left in the other sense (included direction enters " 6 and 9 hours "). The source was so airborne and supersonic. Mac Clure noted the characteristics of the signal: they were those of radars on the ground aforesaid, with the exception of the duration of the impulses, the value 2 microseconds. He did not indicate at once this incident, thinking that it was maybe about a defect of the electronics. As wrote it Klass, it did not exist in the time, neither in the United States nor in the USSR, of rather big supersonic plane to transport a radar the signal of which possessed the observed characteristics.

- The following incident occurred at 10h 10 , in Louisiane, when the major Chase, the pilot, and the captain Mac Coyd, the co-pilot, saw an intense light, of a bluish white, going to the plane in the direction " 11 hours ", may jump up with their left-handler in their right-hand side and disappear while it was in the direction " 2 hours ". Klass showed that this object was maybe a meteorite the trajectory of which provoked an optical illusion, but, over the moment, Chase and Mac Coyd wondered if it was not about an OVNI. Mac Lure, by hearing them, remembered his previous detection, and looked for a signal of the same nature.

- He found this signal at 10h 30 , identical to the precedent, and, by coincidence maybe, from the direction " 2 hours ". This signal was confirmed by the captain Provenzano, for whom the detector was capable of operating too around the 3000 MHz. He could not involve the signal of a fixed radar, because his direction " 2 hours " remained invariable while the plane pursued its road for several minutes westward. The plane penetrated in Texas, then came within reach the radar " Utah ", situated near Dallas. The crew reported to Utah, who discovered at the same moment the plane and the keeping object distant one constant of 18 km with regard to him.

- At 10h 39, always in Texas, the major Chase perceived a red light of big dimension that he estimated to evolve in 1 500 m more low than the plane, appreciably in the direction " 2 hours ". The plane flew from the height of 10 500 m and the time was perfectly clear. Although the major can determine the shape nor the size of the object, he had the net impression that the light emanated down from the object.

- At 10h 40, he received the license to pursue this object and warned Utah. He slows down, then accelerated; Utah informed him that the object accompanied its movements while remaining in distant one constant of 18 km.

- At 10h 42, Chase accelerated and the red object lives turn to the right in the direction of Dallas; this was confirmed by Mac Clure.

- At about 10h 50, little on the West of Dallas, the object stopped, and disappeared simultaneously from the sight of radars (Utah and the board radar which had just discovered the object when RB-47 had got closer to it) and of Mac Lure's screen (the disappearance of the object on the screen of the radar is less surprising nowadays; it evokes the techniques of furtivité activates at present in development, even in service). The plane turned then to the left. Mac Lure got back a signal which was maybe that of Utah. The visual contact was found, as well as the radar contact.

- At 10h 52, Chase lives the object to fall in about 4 500 m. He made make in RB-47 a dive of 10 500m to 6 000 m. The object disappeared then simultaneously from its sight, from the radar Utah, and from Mac Clure's screen.

- At 10h 57, always near Dallas, the object reappeared on Mac Clure's screen, and Utah indicated that he had made a report " CIRVIS " (Communications Instructions for Vital Reporting Intelligence Sightings), report radio urgent and secret, intended for the major of the air, compulsory Defence in case of observation of air object not identified by the Air Force.

- At 10h 58, the pilot found a visual contact at " 2 o'clock ". Some minutes later, seeing its reserves of fuel falling, he decided to return and put the cap appreciably in the North, towards Oklahoma City. The object took place then behind the plane, in 18 km of distance as the préçisa Utah, which tried to send fighter planes in pursuit of the stranger. This one, flying more low than RB-47 and behind him, could not be seen by the cockpit, but it was discovered on Mac Clure's screen until the height of Oklahoma City, the good beyond the reach of the radar Utah. It disappeared then suddenly from the screen at 11h 40. "

C Lakenheath (United Kingdom) ( August 13-14, 1956)

C Teheran ( September 18 to 19, 1976)

C Russia ( March 21, 1990)

C San Carlos of Bariloche ( July 31, 1995)