WASHINGTON -- Pentagon officials reported yesterday receiving "beeper signals" that may be coming from the U.S. Air Force pilot shot down over Bosnia on Friday, providing the first encouraging sign that the flier may still be alive.
As the search for the pilot continued, the Pentagon disclosed that up to 3,500 U.S. Army troops, along with dozens of attack and transport helicopters, would be deployed nearer to Bosnia in Italy in preparation for fulfilling a standing American commitment to help rescue United Nations peacekeepers if necessary.
Until yesterday, U.S. officials had obtained no evidence that the unidentified pilot might have survived the crash of the F-16 fighter after it was shot down over territory controlled by Bosnian Serbs while on a routine patrol. Serbian officials were quoted over the weekend as saying both that they were holding him and that they had no information about him.
"For the last 20 to 24 hours, we have been receiving beeper signals, which is encouraging," a senior Pentagon official told reporters. "We are doing our utmost to locate these signals. The signals alone are not enough to indicate the pilot is alive, but it is encouraging."
Officials cautioned that the device sending the signals, if in fact it belongs to the pilot, might have been picked up by someone else. The device is an emergency beacon that transmits on several different frequencies.
The North Atlantic Treaty Organization and the United States mounted a search-and-rescue effort for the missing airman shortly after his plane went down.
U.S. Marines aboard the USS Kearsarge, an amphibious assault ship steaming in the Adriatic off the coast of the former Yugoslavia, took part in the effort aboard helicopters, but did not search on the ground, according to Col. Fred Peck, a U.S. Marine spokesman.
"From the helicopters, first you've got to spot the wreckage," he said. "Ifyou find the pilot, then you can put people on the ground."
In military jargon, the search effort is called a TRAP, for Tactical Recovery of Aircraft and Personnel.
Colonel Peck said he could not confirm details reported by Newsweek, which said that up to 50 Marines were dispatched to the crash site Friday and Saturday aboard two CH-53 helicopters, with Navy F/A-18 Hornets providing air cover.
The search mission presumably exposes the Marines to the risk of Serbian ground fire, opening the possibility that other U.S. aircraft could be shot down.
The Pentagon continued yesterday to withhold the name of the pilot.
There is often a delay in releasing the names of servicemen missing in action until their families are notified. But in this case, military spokesmen have said they want to know the pilot's fate before identifying him.
Colonel Peck said that if the pilot had ejected from the plane and survived, he would probably now be in hostile territory and might need to hide his identity as a U.S. serviceman.
If his name were released, then photographs of him, perhaps from a high school yearbook, could be transmitted worldwide, the spokesman said.
The new troop movements disclosed yesterday are intended to fulfill Defense Secretary William J. Perry's weekend commitment to U.S. allies to help strengthen the U.N. peacekeeping force in Bosnia.
The troops are coming from bases in Germany.
Mr. Perry had said the United States would provide airlift, attack HTC helicopters and intelligence to the new 10,000-troop quick-reaction forces being put together by Britain and France to bolster the peacekeepers' defenses.
He also said that U.S. troops would be available, if needed, to help rescue trapped peacekeepers, and that the Marines were trained to conduct search-and-rescue missions for downed pilots.
The troop movements were disclosed as Congress was returning from its Memorial Day recess, but before members had a chance to organize any effort to challenge U.S. military action in the Balkans.
President Clinton's shifting statements last week on the possibility of sending ground troops into Bosnia touched off strong criticism from Republicans about his foreign policy leadership, and hearings were scheduled by both the House and Senate.
Secretary Perry and the chairman of the Joint Chiefs of Staff, Army Gen. John M. Shalikashvili, will testify before the two armed services committees tomorrow.
Tentative plans were under way to seek votes both on authorizing any further military involvement in the Balkans and on lifting the arms embargo on the Muslim-led Bosnian government.
Numerous senators and representatives from both parties want the United States, on its own, to ignore the U.N.-imposed arms embargo on the Bosnian Muslims, thus allowing them to obtain weapons and munitions, then sink or swim militarily on their own.
But Sen. John McCain, an Arizona Republican who takes that view, said Congress would await the hearings before taking any decisive steps.