Mystery distress calls heard on radios across the world - including New Zealand - in 1937 probably came from Amelia Earhart, new research has concluded.
It's yet more evidence the aviation pioneer survived when her Lockheed Model 10-E Electra went down in the Pacific, never to be seen again.
Researchers from the International Group for Historic Aircraft Recovery (TIGHAR) say when officials lost contact with Ms Earhart, an ' all ships, all stations' appeal was put out to listen for signals on the two frequencies she'd been using.
While several faint post-crash dispatches - suspected to be from Ms Earhart and her navigator Fred Noonan - were heard on official government or commercial maritime operators, TIGHAR has uncovered evidence their pleas for help were accidentally heard thousands of kilometres away by dozens of amateur radio users.
The calls were reported to authorities, reported on in local newspapers and written about in diaries.
"Plane down on uncharted island," Texas woman Mabel Larremore heard on what would have been the night of July 2 on Nikumaroro - also known as Gardner Island - where TIGHAR suspects Ms Earhart landed. "Small, uninhabited," the woman's voice continued, saying they were partly in the water, partly on land. The voice explained her navigator was seriously injured.
In Kentucky, Nina Paxton heard a woman's voice saying their place was "on or near [a] little island", and was "out of gas. Water all around. Very dark." The voice also appeared to refer to a nearby shipwreck - believed to be that of the SS Norwich City, which sat on the atoll from 1928 until the last of its remains were washed away in 2016.
A few days later, a woman in Canada picked up Ms Earhart's voice.
"Can you read me? This is Amelia Earhart... Please come in," she pleaded. "We have taken in water, my navigator is badly hurt. We are in need of medical car and must have help, we can't hold on much longer."
The SS New Zealand Star picked up one of the first dispatches immediately after the plane went down - a series of Morse Code dashes she reportedly sent after being asked to by a support vessel at nearby Howard Island.
The messages were able to be heard far away after signals known as carrier waves bounced off the ionosphere, TIGHAR says.
Of the 57 dispatches deemed as credible, all but two came at night at low tide - and this was apparently no coincidence.
"The radios relied on the aircraft's batteries, but battery power was needed to start the generator-equipped starboard engine to restart the batteries," the report says.
"If the lost fliers ran down the batteries sending distress calls, they wouldn't be able to start the engine... but on the reef, the tide comes in and the tide goes out. [This] hypothesis would only work if the water level was low enough... for the propeller tip to clear."
One message complained of water being "knee-deep" - about the height of the plane's propeller.
Signals travel much further at night, but the report says it was probably the heat of the metal aircraft in the hot Pacific sun that prompted the pair to avoid making calls during the day, which were likely spent seeking shade, fresh water and food inland.
Though the signals received by officials and amateurs around the globe were weak and often barely intelligible, TIGHAR's analysis found there was a direct correlation between their strength and their distance the receiver was from Nikumaroro.
The last credible call from Ms Earhart was heard on July 7. It's believed the plane was washed over the reef edge into the deep ocean before US Navy planes flew over the atoll on July 9.
A photograph included in TIGHAR's report is said to show landing gear wreckage in the waters off the reef, about 400m from the SS Norwich City.
Bones were found in 1940, but dismissed as belonging to a man. A new analysis using modern techniques earlier this year concluded they were actually from a woman. A navigational instrument called a sextant and a woman's shoe were also found.
Newshub.
