A complex nighttime military operation against Libya, involving at least five dozen aircraft and probably many more, was made more difficult by France's refusal to permit overflights by U.S. F111 fighter-bombers based in Britain, Defense Secretary Caspar W. Weinberger said last night.

Weinberger said U.S. planes had to fly about 2,800 miles over water to reach their targets in western Libya, a round trip of at least 14 hours. Pentagon officials said the bombing plan called for each F111 to be refueled in the air four times on the way to Libya and twice on the return trip, when the bombers could travel farther on less fuel because they had dropped their bombs.

The F111Es from Royal Air Force Base Upper Heyford and the F111Fs from RAF Lakenheath could have shortened their trips by 1,200 nautical miles each way by flying over France, which, Weinberger said pointedly, would have presented "less risk to the pilots." A Pentagon official said two or three dozen tanker aircraft, mostly giant KC10s, had to be put into the air to keep the F111s fueled.

"Obviously, if we had permission to fly a direct route, we would have not subjected the pilots to such a long route," Weinberger said.

Late last night, one F111 was unaccounted for, Pentagon officials said, although Weinberger said there was "no indication" that it had been shot down.

Pentagon officials said they believed that no Libyan fighters were launched to counter the U.S. raid and that no antiaircraft missiles were fired, but they cautioned that such information would remain sketchy until pilots could be debriefed. They said the U.S. force encountered antiaircraft gunfire.

In addition to 18 F111 fighter-bombers and dozens of tankers, at least some of which flew from the United States to RAF Mildenhall earlier yesterday, the U.S. bombing force included 15 A6 and A7 light bombers from the aircraft carriers USS Coral Sea and USS America, Weinberger said. Pentagon officials said that of the Navy planes, only the A6s were to drop bombs.

EF111 electronic jamming planes, designed to prevent enemy radars from homing in on U.S. bombers, also flew from Great Britain. The aircraft carriers launched fighter jets to fly "cap," offering protection to the bombers if needed, and electronic jamming and control planes to guide the bombers and monitor the operation, officials said.

Pentagon officials said three types of "smart," precision-guided bombs were used in an effort to avoid harming civilians near the military targets: laser-guided bombs, which home in on a beam of light flashed from the bomber's underside; electro-optical, which carry a television camera with an image of the target etched in its memory, and infrared, which seek the heat of targets. Both 500-pound and 2,000-pound bombs were dropped, Weinberger said.

Five targets were designated, Weinberger said. In addition, pilots had "free rein" to attack radars or antiaircraft missile sites deemed to represent a threat to the planes, other officials said.

Administration officials said all five targets were linked to Libyan terrorist operations: the Azizyah Barracks in Tripoli, which a Pentagon official described as "the main headquarters for Libyan planners of terrorist attacks overseas"; the Jamahiriyah Barracks, described as an alternate command post in Benghazi; the Sidi Bilal port west of Tripoli, described as a training base for Libyan undersea commandos; the military side of the Tripoli airport, where officials said Soviet-built IL76 cargo aircraft take off to supply missions in other countries, and the Benina military airfield, home base for Libyan operations in Chad.

The F111 force attacked targets around Tripoli, while the carrier-based force attacked eastern targets near Benghazi. Little damage assessment was available last night.

It was also unclear last night why the Navy, with about 160 warplanes on its two carriers north of Libya, did not carry out the raids without Air Force assistance. The Pentagon has been criticized in the past for the desire of each service to have a part in every operation, but Weinberger said the raid -- "a very difficult one from the professional point of view" -- was carried out with "very great skill" and "precisely as planned."