Paris - The United States is providing ultra-sensitive detection equipment to help in the search for the missing Air France jetliner, the head of the Office of Accident Office of Accident Investigations and Analyses (BEA) said Saturday in Paris.

The equipment is to be transported on two ships to the search zone, which is located about 1,200 kilometers off the coast of Brazil - a French research vessel with a robot diver and a submarine, Paul-Louis Arslanian said.

Both ships are able to recover objects at depths of up to 6,000 meters.

In addition, the French nuclear-powered submarine Emeraude, equipped with very sensitive sonar, is also being deployed to the area.

"We are not counting on just luck," Arslanian said.

Five days after the plane went missing on a flight from Rio de Janeiro to Paris with 228 people aboard, not a trace of it or its occupants has been found.

Arslanian raised the possibility that the two black boxes - a flight data recorder and a cockpit voice recorder - may have become detached from the beacon that sends out an ultrasonic signal for 30 days.

That could mean that the boxes were lost forever, and that the cause of the accident may never be determined.

The BEA said that the plane sent 24 failure signals in the five minutes before contact with the aircraft was lost early Monday.(dpa)