NEW YORK, July 5 (Reuters) - The U.S. National Transportation Safety Board on Monday said it has recovered debris from a downed Boeing 737-200 cargo plane and will continue to investigate the cause of the aircraft"s emergency water landing, which injured two people, off Hawaii last week. Investigators plan to use sonar technology to locate the decades-old plane, which was substantially damaged and sank, and recover cockpit voice and flight data recorders, the NTSB said in a statement. "That information will be used to determine how and when the recorders could be recovered and then how and if the airplane will be salvaged," the agency said. Both of the two-member crew on Transair Flight 810 were injured after being forced to land in the Pacific Ocean early on Friday, the NTSB said. The agency did not disclose the extent of the injuries. The crew reported engine trouble and plans to turn back shortly after taking off at 1:33 a.m. local time from Daniel K. Inouye International Airport in Honolulu en route to the Hawaiian island of Maui. A U.S. Coast Guard helicopter, responding to reports of the downed plane, spotted a debris field and found one crew member clinging to the plane"s tail roughly an hour after takeoff. Another survivor was found using packages as a flotation device. One crew member was taken to a hospital by helicopter and the other was rescued by boat. The NTSB said it is scheduling interviews with the flight"s crew, as well as air traffic controllers and maintenance workers.