WASHINGTON (AFP) - Researchers on the trail of missing 1930s aviatrix Amelia Earhart say they are increasingly convinced that aluminium debris found on a South Pacific beach came from her lost airplane.
The International Group for Historic Aircraft Recovery (TIGHAR) said the debris bolsters the possibility that a sonar blip off Nikumaroro atoll in Kiribati is the fuselage of her ill-starred Lockheed Electra.
Earhart, the first woman to fly solo across the Atlantic, was attempting to circumnavigate the world in 1937, flying close to the equator, when she and navigator Fred Noonan vanished without a trace. She was 39 at the time.
What happened to the duo and their twin-engine aircraft has remained one of aviation's enduring mysteries.
In a statement, TIGHAR said the chunk of aluminium, found in 1991, strongly resembles a 48-by-58cm patch installed in place of a window on the Electra during a stopover in Florida earlier during the flight.
"The strong possibility that Artifact 2-2-V-1 is the 'Miami Patch' means that the many fractures, tears, dents and gouges evident on the metal may be important clues to the fate - and resting place - of the aircraft itself," the statement said.
It also reinforces the possibility that an "unusual feature" seen in sonar images taken by a TIGHAR expedition to the atoll in 2012 might be Earhart's lost plane, resting 200m beneath the sea.
One theory, the researchers said, assumes that the patch was removed after Earhart and Noonan, possibly out of fuel, crash-landed on a reef at Nikumaroro - known at the time as Gardner Island - and sent out radio messages for at least five days.
Rising tides and surf would have then washed the aircraft into the sea, leaving the two aviators stranded, waiting for a rescue that never arrived.
Pennsylvania-based TIGHAR said it plans to return to Nikumaroro in June 2015 with a Fiji-based research vessel for a sixth expedition that will send a remote-operated underwater vehicle to investigate the unexplained sonar anomaly.
"During the 24-day expedition, divers will search for other wreckage at shallower depths, and an onshore search team will seek to identify objects detected in historical photographs that may be relics of an initial survival camp," it added.
Earlier this year, another Amelia Earhart, a 31-year-old US broadcast journalist, honoured her namesake by circumnavigating the world in a high-performance Pilatus turboprop. She claims to be the youngest woman ever to do so in a single-engine aircraft.