BY TIM JOHNSON

 NEIVA, Colombia -- Drug-laden aircraft have had a field day sneaking out of
 Colombia over the Pacific Ocean since the United States closed a major airbase
 in Panama last year, ending constant radar surveillance of western Colombia, the
 defense minister said Friday.

 Although a temporary gap in coverage was expected when U.S. flights out of
 Panama came to an end, Colombian authorities seem alarmed by the extent of
 the problem. An unfortunate ``window of opportunity'' has been thrown open for the
 drug trade, Defense Minister Luis Fernando Ramirez said.

 That window is supposed to close once the U.S. military can improve a base in
 Manta, Ecuador, to handle heavy, radar-bearing aircraft to cruise the Pacific
 coast, U.S. officials say. But improvements at the base will take many months,
 and work hasn't even yet begun.

 Ramirez said the lack of radar coverage in western Colombia is only one of
 several challenges facing authorities as they mount a campaign against the drug
 trade and the leftist guerrillas who protect it.

 Rebels, distressed at the growing air power of Colombia's security forces, have
 taken to firing anti-tank missiles at low-flying military aircraft, he said.

 In the past month, guerrillas in southeast Colombia have shot at aircraft eight
 times with the missiles, known as RPG-7s, he said. None were hit.

 Ramirez also predicted that angry coca farmers may soon launch marches to
 protest aggressive coca eradication efforts, as they did in mid-1996, when violent
 protests forced a temporary halt to aerial spraying.

 Ramirez offered an impromptu evaluation of Colombia's counter-drug efforts during
 visits to an airbase in this city, 140 miles southwest of Bogota, and to a
 7,500-foot-high, sheer Andean slope containing poppy, a wine-red flower that
 produces a latex gum used in making heroin.

 LESS COVERAGE

 Referring to radar coverage of Colombia's skies, Ramirez said counter-narcotics
 efforts have suffered since the closing last May of Howard Air Base in Panama,
 which the Pentagon used to deploy sophisticated radar aircraft to crisscross the
 skies of Colombia and fill in gaps from radar stations on the ground.

 In testimony before Congress last year, Ana Maria Salazar, the Pentagon's
 deputy assistant secretary for drug enforcement policy, acknowledged that there
 would be an initial ``degradation'' of antidrug operations because of the shutdown
 of Howard. But the discovery that drug traffickers are taking advantage of the radar
 gaps and will apparently continue to fly unchecked for a prolonged period has
 troubled the Colombian government.

 ``We have seen a rise in air traffic going west, and basically while no airbase
 exists in Manta to obtain more information, the Pacific is totally uncovered by
 radar,'' Ramirez said, noting that cocaine-laden airplanes fly out over the Pacific
 before heading to Mexico and the western United States.

 The U.S. military has won agreement from Ecuador to lengthen and fortify the
 Manta base to handle the radar-heavy aircraft -- such as the P-3 Orion and the
 AWACs -- but improvements to the airstrip have not yet started.

 ``If an AWACs landed twice there now, it would rip up the whole runway,'' said one
 U.S. official, noting the heaviness of the aircraft.

 Ecuador's elected president, Jamil Mahuad, was toppled in a military-backed
 overthrow Jan. 21, and his successor, former Vice President Gustavo Noboa, is
 still organizing his government.

 Sophisticated U.S. planes continue to monitor Colombian skies but with less
 frequency than before, Ramirez said, and deploying from a greater distance.

 ``They can't react as fast. They left from Panama before and could get here
 quickly. Now they come from Miami,'' he said.

 In addition to radar at civilian airports in large cities, Colombia hosts three
 U.S.-owned ground-based radar stations in Leticia on the Amazon River, San
 Jose del Guaviare and in Marandua in far eastern Vichada state.

 `NO-MAN'S LAND'

 Ramirez described the three radar bases in eastern Colombia as offering ``very
 limited coverage'' with a radius of less than 200 miles, leaving ``very ample swaths
 of territory . . . that is no-man's land, that is not watched.''

 A spokesman for the U.S. Southern Command in Miami, which oversees U.S.
 military operations in Latin America, would not confirm the radius of the
 ground-based radar, saying it was classified information. The spokesman had no
 comment on the reported gaps in radar coverage.

 Colombia is staggering under a huge increase in domestic coca production, and
 is the focus of renewed attention from Washington. Last month, President Clinton
 urged Congress to approve an extraordinary two-year plan for $1.3 billion in
 counter-drug assistance to Colombia.

 ``We must stand by democracies -- like Colombia, fighting narco-traffickers for its
 people's lives, and our children's lives,'' Clinton said in his State of the Union
 address Jan. 27.

 CIA Director George Tenet told a Senate Intelligence panel Wednesday that due
 to better coca varieties and more efficient processing, Colombia produces ``more
 than two and a half times'' the cocaine that was previously estimated.

 While Ramirez lamented the lack of radar coverage in Colombia, both he and
 National Police Chief Rosso Jose Serrano praised recent donations of three U.S.
 Blackhawk helicopters to Colombia.

 As dozens of journalists clung to a sheer Andean slope, and sharpshooters stood
 guard around Serrano and Ramirez, crop-dusting planes swooped into a ravine
 and sprayed a poppy field with herbicide.

 As the crop-dusters made multiple passes, the three Blackhawk helicopters
 buzzed in the distance, occasionally spraying gunfire into the ravine banks. The
 Blackhawks were donated Nov. 1, but officially inaugurated on Friday.

 Serrano said the Blackhawks, equipped with up to .50-caliber machine guns, will
 make drug traffickers ``tremble with fear'' if they try to shoot at the fumigation
 planes in the future.

 Last year, police aircraft took fire 35 times from presumed leftist rebels guarding
 poppy and coca fields, although no pilots were wounded, said a U.S. official, who
 spoke on condition of anonymity.

                     Copyright 2000 Miami Herald