Date: 
                      July 17, 1957
                      Location: Gulf Coast Area, United States
                       
                      An 
                        Air Force RB-47, equipped with electronic countermeasures 
                        (ECM) gear and manned by six officers, was followed by 
                        an unidentified object for a distance of well over 700 
                        mi. and for a time period of 1.5 hr., as it flew from 
                        Mississippi, through Louisiana and Texas and into Oklahoma. 
                        The object was, at various times, seen visually by the 
                        cockpit crew as an intensely luminous light, followed 
                        by ground-radar and detected on ECM monitoring gear aboard 
                        the RB-47.
                      
                        The RB-47 aircraft.
                      
                        Map of the RB-47 UFO encounter. (James McDonald)
                      Source: 
                        Loy Lawhon
                      The 
                        Best UFO Case Ever?
                      On 
                        board an RB-47H aircraft equipped with sophisticated electronic 
                        countermeasures equipment, over the Gulf of Mexico.
                      The 
                        crew consisted of:
                        Lewis D. Chase, pilot, Spokane, WA
                        James H. McCoid, copilot, Offutt AFB
                        Thomas H. Hanley, navigator, Vandenberg AFB
                        John J. Provenzano, No. 1 monitor, Wichita, KS
                        Frank B. McClure, No. 2 monitor, Offutt AFB
                        Walter A. Tuchscherer, No. 3 monitor, Topeka, KS
                      These 
                        six men were on a training/test exercise in an RB-47H 
                        electronic countermeasures reconnaissance aircraft. The 
                        RB-47, while originally developed as a bomber, was also 
                        used extensively as a reconnaissance aircraft. One was 
                        shot down by the Soviet Union while on such a mission 
                        in 1960.
                      This 
                        particular mission began at Forbes AFB in Topeka, Kansas 
                        as an exercise including gunnery exercises over the Texas-Gulf 
                        area, navigation exercises over the open Gulf, and Electronic 
                        CounterMeasures exercises on the return trip across the 
                        south-central U.S.
                      The 
                        men participating were soon to depart for Germany and 
                        duty there. It should be noted that the ECM equipment 
                        was not radar. It did not emit a signal and then pick 
                        up reflected echoes off of an object. Rather, it detected 
                        electromagnetic signals that were actually emitted by 
                        an object itself. The purpose of this was to detect and 
                        locate enemy radar installations. On this aircraft, the 
                        #2 monitor consisted of a direction finder with antenna 
                        on the lower rear of the aircraft, and the #1 monitor 
                        consisted of a direction finder with antennas on each 
                        wingtip of the aircraft. The #3 monitor was not involved 
                        in the events of July 17, because its range did not include 
                        the frequencies involved. The first contact with the unknown 
                        object was before 4:00 AM CST. The first two parts of 
                        the mission had been completed, and the aircraft was just 
                        leaving the airspace over the Gulf of Mexico near Gulfport, 
                        Mississippi, when Frank McClure, on the #2 ECM monitor, 
                        detected an airborne signal to the right rear of the aircraft, 
                        out over the Gulf of Mexico. The signal was of a type 
                        usually confined to ground-based radar installations. 
                        It was at 2800 megacycles, a common frequency for S-band 
                        search radar. McClure, at first, thought that his scope 
                        must be 180° out of alignment and that he must be 
                        picking up a ground-based radar station in Louisiana, 
                        which would actually be to the left front of the aircraft. 
                        As he watched, the signal moved up the scope, as it would 
                        if the scope was 180° out of alignment. However, he 
                        was amazed to see that, after it had moved up the scope 
                        on the right-hand side of the aircraft, it then crossed 
                        the path of the RB-47 and proceeded to move down the scope 
                        on the left-hand side. In other words, whatever was emitting 
                        the signal flew a ring around the RB-47, which was flying 
                        at approximately 500 mph. Even if the scope was 180° 
                        out of alignment, the signal source still moved completely 
                        around the aircraft, which no ground radar could do. McClure 
                        said and did nothing at this time, not mentioning the 
                        signal to the other crew members. The signal faded as 
                        they flew north.
                      The 
                        RB-47 made a scheduled turn to the west over Jackson, 
                        Mississippi and the crew was preparing to begin a series 
                        of simulated ECM operations against Air Force ground radar 
                        units, when suddenly the pilot, Lewis Chase, saw a light 
                        coming in from the left, at approximately the same altitude 
                        as the RB-47. At first, he thought it was another plane, 
                        but it was only a single white light, closing fast. He 
                        gave the command to prepare for evasive maneuvers, but 
                        the light flashed across from left to right so fast that 
                        no such action could have been taken. It then blinked 
                        out at a point to the right front of the aircraft. Both 
                        Chase and Co-pilot James McCoid observed this. At this 
                        point, approximately 4:10 AM CST, they were approximately 
                        over Winnsboro, Louisiana.
                      Chase 
                        told the other crewmembers what he had seen, and McClure 
                        now told him about his earlier signal reading. At 4:30 
                        AM, McClure set his scope to detect signals near 3000 
                        mcs again, and he detected a strong signal at the same 
                        location in relation to the RB-47 that Chase had last 
                        seen the light. He and Provenzano checked the alignment 
                        of the #2 monitor by tuning in on known ground radar installations 
                        and found it to be in perfect working order. At 4:30 AM, 
                        Provenzano tuned his own monitor, #1, to 3000 mcs, and 
                        found that his equipment detected a signal at the same 
                        location. What's more, he and McClure found that the signal 
                        was staying in the same position, keeping pace with the 
                        RB-47, which was still flying at 500 mph. This meant that 
                        it was not a signal from a ground-based radar.
                      The 
                        Unknown Companion
                      By 
                        this time, they had reached the Duncanville, Texas area. 
                        At 4:39, Chase spotted a huge light to the right front 
                        of the RB-47 at about 5,000 feet below the aircraft's 
                        34,500 feet altitude. The weather was perfectly clear. 
                        At 4:40, McClure reported two signals, at 40° and 
                        70°. Chase and McCoid reported seeing red lights at 
                        those locations. Chase contacted radar Station Utah at 
                        Duncanville, Texas and requested permission to abandon 
                        his flight plan and pursue the lights, which he received. 
                        At 4:48 AM, radar station Utah requested the position 
                        of the signals that McClure was receiving, and they immediately 
                        confirmed that their radar had detected the objects at 
                        the same location. As the RB-47 attempted to pursue, the 
                        object appeared to stop suddenly. Chase could see that 
                        they were gaining on it, and they over shot it.
                      At 
                        4:52, it blinked out, and simultaneously vanished from 
                        McClure's scope and the ground radar! Chase put the aircraft 
                        into a port turn, and the object suddenly blinked on again, 
                        simultaneously reappearing on McClure's scope and the 
                        ground radar at 4:52! They began to close to within 5 
                        miles of the object, when it suddenly dropped to 15,000 
                        feet and then blinked out again, once again vanishing 
                        from the scopes and ground radar. At 4:55, Chase radioed 
                        Utah radar station that they had to break of pursuit and 
                        continue with their scheduled flight plan due to low fuel. 
                        At 4:57, McClure picked up the signal again, and at 4:58, 
                        Chase made visual contact again. As they headed into Oklahoma, 
                        McClure continued to receive a signal, now from the rear 
                        of the aircraft, until it finally faded as they neared 
                        Oklahoma City. The Director of Intelligence, 55th Strategic 
                        Reconnaissance Wing, stated in his report that he had: 
                        "...no doubt the electronic D/F's coincided exactly 
                        with visual observations by aircraft cmdr numerous times, 
                        thus indicating positively the object being the signal 
                        source."
                      What 
                        can be detected on ECM direction finding devices, can 
                        be seen visually, and can be detected on ordinary ground-based 
                        radar all at the same time? What can be detected by all 
                        the sensors and can also fly rings around a jet travelling 
                        at 500 mph?
                      Project 
                        Bluebook said that the sightings in Dallas-Fort Worth 
                        area were an ordinary jet airliner. They couldn't explain 
                        the abrupt, simultaneous disappearance and reappearance 
                        of the object from radar screens, ECM scopes, and visual 
                        detection. They also couldn't explain the events that 
                        occurred over Mississippi and Louisiana. It's odd that 
                        the Utah radar station couldn't tell an airliner from 
                        an unknown.
                      The 
                        Condon Committee toyed with several explanations, but 
                        found none to be satisfactory, finally classifying this 
                        case as unknown. 
                       
                      Source: 
                      http://www.ufoevidence.org/cases/case665.htm