Effets gravitationnels et/ou inertiels apparents

In his presentation, Swords focused on reports with details that, if true, are difficult to understand in terms of our familiar concepts of gravity and inertia. For instance, a report may describe an object that is stationary, yet completely silent and has no visible means of support; there is no rush of air and no roar such as one would expect if the object were being supported by a downward jet of gas. It may be reported that the object makes an abrupt velocity change ? either a very sudden acceleration or deceleration, or a sudden change of direction, or both, and the witness may describe the event as being completely silent. According to Newton's third law of motion, any sudden change of momentum of an object should be accompanied by an opposite change of momentum of either matter or a field to which the object is coupled. According to reports of the type described by Swords, there is no indication of what force might support the object or what momentum transfer may have occurred.

It is clear that future reports must, if they are to be considered seriously by physical scientists, include very solid physical records that unfortunately present reports do not: most of these cases are anecdotal and therefore very difficult to assess. One of the better-documented cases occurred at approximately 11:00 p.m. on August 18, 1973. At that time, a helicopter of the US Army Reserve was en route from Columbus, Ohio, to Cleveland, Ohio. In discussing this case, Swords drew upon an investigation by Ms. Jennie Zeidman on behalf of the Center for UFO Studies (Zeidman, 1979; see also Zeidman, 1988). The four-man crew of an Army Reserve helicopter based in Cleveland, Ohio, flew to Columbus for their regularly scheduled physical examinations. At about 10:00 p.m., after the examinations had been concluded, they left the medical facility, drove back to the airport (a distance of two miles), filed a flight plan, and then took off at approximately 10:30 p.m. The night was clear, calm, starry and moonless, with 15-mile visibility. The helicopter was cruising at 90 knots at an altitude of 2500 feet mean sea level over mixed terrain averaging 1100 to 1200 feet elevation.

According to their reports, one of the crewmen saw a single red light off to the left (west), apparently heading south, when they were about seven miles east-southeast of the Mansfield, Ohio, airport. The last altitude the commander noted was the initial altitude of 1800 feet msl (mean sea level), about 700 feet above ground level. At approximately 11:02 p.m. (about three to four minutes after the above observation), the crew member in the right rear seat noticed a single steady red light on the eastern horizon. It appeared to be pacing the helicopter, and he reported this light to the aircraft commander. The light continued its approach and the commander took over the controls from his copilot and put the helicopter into a powered descent of approximately 500 fpm (feet per minute). He contacted Mansfield control tower but, after initial radio contact, the radios malfunctioned on both VHF and UHF. The red light increased in intensity and appeared to be on a collision course at a speed estimated to be above 600 knots. The commander increased the rate of descent to 2000 fpm.

A collision appeared imminent, but the light suddenly decelerated and assumed a hovering relationship above and in front of the helicopter. The crew reported seeing a cigar-shaped gray metallic object that filled the entire windshield. It had a red light at the nose, a white light at the tail and a distinctive green beam that emanated from the lower part of the object. The green beam swung up over the helicopter nose through the main windshield and into the upper tinted window panels, bathing the cockpit in green light. There was no indication of noise or turbulence from the object. After a few seconds of hovering, the light accelerated and moved off to the west, showing only the white "tail" light. The object made a sharp 40 degree course change during its departure.

While the object was still visible, the crew noted that the altimeter read 3500 feet with a rate of climb of 1000 fpm, despite the fact that the collective (the main power control that causes a helicopter to ascend or descend) was still in the full-down position. The commander raised the collective and the helicopter climbed nearly another 300 feet before positive control was re-gained, at which time the crew felt a slight bump. Radio contact with Akron/Canton was then easily achieved. If these accounts are correct, the helicopter ascended from 1800 feet to about 3800 feet even though the helicopter controls were set to cause it to descend.

The Mansfield helicopter case is a particularly puzzling event since it involved not only the testimony of the helicopter crew but that of independent ground witnesses also. These witnesses include a mother, three of her children (ages 13, 11 and 10), and a stepchild (age 13). The witnesses were originally driving in the family automobile, then parked it, whereupon two of the children got out of the car for a better view. All the witnesses first saw an unidentifiable pair of lights (one red, one green), and then the encounter between the "object" responsible for the lights and the oncoming helicopter. Their accounts are consistent in their essential elements, the most memorable aspect being the powerful green light that lit up both the ground and the helicopter. This element received further confirmation from another set of witnesses who were retiring that evening in a nearby house, when they were disturbed by the clattering of a helicopter and by a powerful beam of green light that swept over their house and brightly illuminated their son's bedroom. Related evidence comes from an airline pilot who (in the Mansfield area, about 1.5 hours before the helicopter event) reported unidentified traffic that had the appearance of a strong blue-green light source traveling at an altitude of about 30,000 feet. Cleveland ATC could not detect any object painting an image on their radar screens and so were unable to identify the object.

According to Swords, there was one item of physical evidence that could have been investigated but apparently was not. The commander reported that the magnetic compass began to spin during the event. The compass continued to spin after the event and it was subsequently removed because it was unserviceable. Swords reported that some years after the event Captain Coyne expressed the opinion that his compass, that had not previously malfunctioned, had somehow become demagnetized, but it was not clear whether this opinion was merely a conjecture or whether it was based on laboratory tests.

The panel finds reports of this type quite interesting, but without the existence of any solid physical evidence (such as analysis of the magnetic compass might have provided), it is difficult for a panel composed of physical scientists to draw any conclusions. The panel also found it curious that the commander did not know where to go to report what appears to have been an extraordinary event. He contacted the Federal Aviation Authority Chief of Operations at Hopkins field, but this official could not suggest an agency with which the commander should file his report. About a month later, the commander filled out an operational hazard report. Rodeghier advised the panel that, since the termination of Project Blue Book in late 1969, there has been no official body to receive UFO reports in the U.S.A.

For further information about the Mansfield helicopter case, see Section 15.