In the nearly three months since U.S. Navy jet fighters shot down two Libyan warplanes over the Mediterranean Sea, intense review of electronic data recorded during the encounter has yielded details about the maneuvers and conversations of the American and Libyan pilots and their controllers and superiors on the ground and at sea. But core mysteries and contradictions remain and may never be satisfactorily solved. One of the major questions is: What mission were the two Libyan MiG23 fighters carrying out on Jan. 4 when they approached the aircraft carrier USS John F. Kennedy and its combat air patrol of two F14 Tomcat fighters? According to House Armed Services Committee Chairman Les Aspin (D-Wis.), who was given secret Pentagon briefings and has discussed the episode with Egyptian President Hosni Mubarak, both the U.S. intelligence community and the Egyptian defense ministry remain mystified about the MiGs' mission. In an interview, Aspin said the United States had its eavesdropping net spread out during the shootdown and that Egypt monitored the fight, but that neither intelligence network answered the key question of what the Libyan pilots were told before they took off to meet the two F14s flying south toward Libya. "What we need and don't have -- to answer the question of what they had in mind -- is what the Libyan pilots were told in the ready room," Aspin said. "It's likely we're never going to know." Aspin, who toured Arab capitals several weeks after the incident, said high officials in Egypt, Libya's neighbor, and Jordan "just rolled their eyes" when he asked them what the Libyans may have had in mind. "It was as if they were saying, 'With those crazy Libyans, you never know.' " He said the Libyans could have been conducting an innocent reconnaissance mission, as Tripoli claimed, or setting the Libyan pilots up to be shot down to rally Arab opinion behind Libyan leader Moammar Gadhafi. The Pentagon said at the time that the Libyan pilots kept maneuvering to get in firing position while the Navy pilots tried to avoid the MiGs before shooting them down in self defense. Aspin said this central part of the Pentagon's justification did not stand up in the secret briefings he received. The Pentagon has said the Libyan pilots never turned on the radar needed to guide their long-distance Apex missiles into the oncoming F14s. Former defense secretary Frank C. Carlucci said the threat of these Apex missiles justified the radar intercept officer, or "RIO" riding in the backseat of the lead F14, to open fire from a distance of 12 miles with his Sparrow missile. Aspin said that while the Libyans' manuevering was too slight to be considered hostile, the fact that the Libyans, with a history of shooting first, accelerated as they neared the F14s by kicking on their planes' afterburners justified the Navy action of shooting first. He said that Egyptian and Jordanian officials privately endorsed the Navy action, despite their public statements to the contrary. Navy aviators interviewed about the shootdown reinforced Aspin's assertion that the administration had inaccurately portrayed standard intercept manuevers as "avoidance" and had overstated Libyan maneuvering before the shooting started. They said that after plotting the Pentagon's description of the turns made by the F14s and MiG23s and listening to the tape of the F14 cockpit conversations, they concluded that the Navy pilots in the incident were striving for the standard "offset" position to one side or the other of the oncoming planes. The advantage of "offset," they said, is to put the F14s in position to get frontal shots into the oncoming hostile planes with radar-riding Sparrow missiles and heat-seeking Sidewinder missiles, which can be fired from any quarter. Another advantage, they said, is that the offset position shortens the distance the F14s have to travel if they want to swing behind the oncoming aircraft for rear-quarter shots or to assume the standard position for escorting potentially hostile aircraft. The pilot of the lead F14 which began the firing is nicknamed "Beads" and his backseater "Leo the RIO" (radar intercept officer). They are veteran aviators who, according to fellow fliers, followed standard intercept procedures on Jan. 4, until Leo took the unusual step of firing the first Sparrow radar-guided missile without first consulting with his pilot or higher authority. "Leo was the one doing the jinking," said one F14 aviator in describing the maneuvers directed by the radar intercept officer sitting in the back seat of the lead Navy F14. He said the maneuvering "calls" made by Leo put his lead F14 and the second F14 wingman into much sharper turns than the Libyans executed. The Libyan jets were being directed by a ground controller in Tobruk, more than 50 miles away, whose search radar was unable at that distance to keep the Libyan pilots abreast of each maneuver by the Navy jets. In describing the shootdown during a briefing at the time, Pentagon spokesman Dan Howard stressed that the F14s made five "avoidance" maneuvers. He said the Navy jets were properly protecting the aircraft carrier, which was steaming 127 miles off the Libyan coast. "I have nothing to alter at all" about the explanations, he said, adding that manuevers "are subject to different interpretations." Aspin said the secret briefings he received from a representative of the Joint Chiefs of Staff and other information the committee received "made the Carlucci avoidance business sound pretty much like b.s." A Pentagon official steeped in the rules of engagement for military pilots said that "if the pilots had been Russians and done the same thing {as the Libyans}, they wouldn't have been shot down." He said U.S. and Soviet fighter pilots have frequently engaged in mock aerial combat after spotting one another and have built up a trust that does not exist between U.S. and Libyan fliers. Whether the Libyan ground controller intended to order the MiGs to fire when they got close to the F14s or call them home remains unknown despite the wide eavesdropping net, Aspin said. The elaborate U.S. intelligence net that left these and other questions unanswered included what one Pentagon official termed "three platforms." While he did not identify them, other military officials said it is standard procedure during operations off such hotspots as Libya to have a National Security Agency "Burning Wind" aircraft aloft with Arab-speaking technicians aboard, listening to communications. The Navy relies heavily on a converted A3D bomber called "The Whale" for similar eavesdropping. Satellites are another part of the net. Pentagon spokesman Fred S. Hoffman said the Libyans knew "full well" the Navy F14s were there before the shooting started. According to those who have read them, the intercepts confirm that the ground controller sent the MiG23s toward the F14s and late in the intercept track said, "Look to the right." It is not known whether the Libyan pilots did so, or what they saw, if anything, when they looked to the right, officials familiar with the intercepts said. Another intercept of a Libyan pilot talking suggests he saw the F14s, but the distance between the F14s and MiGs just then was so great that it casts doubt on whether he did, sources said. The intercepts also indicate that at least one of the MiG23 pilots knew he was "painted" by F14 fire-control radar and may have been homing in on it. But the evidence is not conclusive that the pilot saw the F14s with his eyes before the shooting started, specialists said. In interviews, several Navy officials said they were told the Libyans "never knew we were there" until Leo launched the first Sparrow from 12 miles away. Aspin said this cannot be proved from the intercepts; Pentagon spokesman Hoffman said the Libyan pilots knew where the Americans were, but experienced Navy aviators familiar with the limitations of the one-seater MiG23 theorized the Libyans may have been surprised by the Navy fighter. Noting that the F14s had positioned themselves below the MiGs, forcing the Libyans to try to find them in the radar clutter generated by the ocean or rely on their distant ground controller, one aviator said: "The MiG23 radar is virtually blind looking down like that. And the pilots would have have gotten only a few 'paints' {radar detections} from the ground controller" because surveillance radar does not provide the constant and precise updates of an enemy plane's location as does fire-control radar, which the Libyans had not turned on. The Soviet-built MiG23 "is a pig," said pilots who know the most about it. "It's virtually blind," especially looking down, one pilot said. "All it can do is go fast." Pilots said the MiG23 with afterburner operating can accelerate to 950 mph at low altitude compared to about 650 mph for the F14 Tomcat. "If the MiG is coming toward the carrier," said one F14 pilot with hundreds of hours of flying in the Mediterranean, "you have to worry about him blowing past you. If he blows past you, you can't catch him and have to worry about him firing an air-to-surface missile at the carrier. But otherwise the MiG23 is a pig." One reason U.S. fliers know so much about the MiG23 is that a few have flown it and many more have seen it at "Dreamland," the Air Force's secret base in Nevada where captured or purchased foreign aircraft are tested, according to Pentagon officials. The obligation of Navy fliers to protect their carrier from hostile aircraft increases the likelihood they will take "preemptive action" in uncertain situations like the January encounter, according to a Pentagon specialist on military rules of engagement. But the Arab nations took another view. During debate at the United Nations after the shootdown, Arab representatives accused the United States of an unjustified attack on a harmless reconnaissance flight. Then-U.S. Ambassador to the United Nations Vernon A. Walters likened the episode to "walking down a dark alley at night, and you see a man who has a gun, and you cross the street, and he crosses the street; you speed up, and he speeds up; you slow down, and he slows down. I think you have to realize that he is not coming to present you with a bouquet of flowers." Ambassador Klaus Tornudd of Finland took another tack, calling for new rules to prevent such aerial clashes in the future: "According to the explanations. . . the recent incident occurred between two aircraft on one side, described as being on routine patrol, and two aircraft on the other side, described as carrying out routine operations. There must be something wrong with the routines, if this is the result. "There seems to be a need for an international code of conduct concerning both naval forces and aircraft in order to make it possible to build confidence, to avoid the possibility of misunderstandings about the intentions of others and to reduce the risk of serious incidents. Rules regarding the behavior of patrolling aircraft and reconnaissance flights could be internationalized and formalized in such a manner that those activities would not be perceived as provocative and threatening."