BLACK HAWK COPTER CRASHES; 23 COLOMBIAN SOLDIERS KILLED • A Colombian Army Black Hawk helicopter crashed today as it hunted leftist guerrillas in a mountainous part of northern Colombia, killing all 23 soldiers on board, the army said. The helicopter went down in bad weather near the town of Curumaní and Pailitas in César Province, about 300 miles northeast of Bogotá, the capital, the army said in a news release. ''The commander of the army and all its personnel express their solidarity with the valiant soldiers who have given their lives,'' it said. All the soldiers were Colombians attached to an elite rapid-deployment army force. It was the worst setback for Colombia's military aviation since rebels shot down another Black Hawk in October 2000, killing more than 20 aboard. The American-made aircraft are used as both attack helicopters and troop transports. Thousands of people are killed every year in Colombia's four-decade-old war, which pits leftist rebels and far-right paramilitary outlaws against the American-backed army. The United States has spent nearly $2 billion in recent years in military aid to help Colombian troops and the police fight the booming cocaine industry. Last year, Washington allowed the Colombians to use the aid to combat other groups as well. Although the armed forces are still overstretched to combat an estimated 20,000 guerrillas in the country's Andean ranges and thick jungles, the military has made significant improvements in its mobility and air-borne strategy, dealing military blows to rebels on the battlefield. President Álvaro Uribe, a conservative who took office in August, is lobbying for more American aid. Colombia is the third-largest recipient of United States military assistance.