[Milsurplus] OT: Amelia Earhart

[J. Forster]

Copied from
<http://www.foxnews.com/scitech/2012/06/01/previously-dismissed-radio-signals-were-credible-transmissions-from-earhart/>.
 At this URL are links to related stories/photos.  -C.


Previously dismissed radio signals were credible transmissions from Earhart

Dozens of previously dismissed radio signals were actually credible
transmissions from Amelia Earhart, according to a new study of the alleged
post-loss signals from Earhart's plane.

The transmissions started riding the air waves just hours after Earhart
sent her last inflight message.

The study, presented on Friday at a three day conference by researchers of
The International Group for Historic Aircraft Recovery (TIGHAR), sheds new
light on what may have happened to the legendary aviator 75 years ago. The
researchers plan to start a high-tech underwater search for pieces of her
aircraft next July.

"Amelia Earhart did not simply vanish on July 2, 1937. Radio distress
calls believed to have been sent from the missing plane dominated the
headlines and drove much of the U.S. Coast Guard and Navy search," Ric
Gillespie, executive director of TIGHAR, told Discovery News.

"When the search failed, all of the reported post-loss radio signals were
categorically dismissed as bogus and have been largely ignored ever
since," he added.

Using digitized information management systems, antenna modeling software,
and radio wave propagation analysis programs, TIGHAR re-examined all the
120 known reports of radio signals suspected or alleged to have been sent
from the Earhart aircraft after local noon on July 2, 1937 through July
18, 1937, when the official search ended.

They concluded that 57 out of the 120 reported signals are credible.

"The results of the study suggest that the aircraft was on land and on its
wheels for several days following the disappearance," Gillespie said.

Earhart used radio transmissions on her last flight on July 2, 1937,
during her record attempt to fly around the world at the equator.

At 07:42 local time, as she flew toward the target destination, Howland
Island in the Pacific, with her navigator Fred Noonan, Earhart called the
Coast Guard cutter Itasca, stationed at Howland Island to support her
flight.

“We must be on you, but cannot see you -- but gas is running low. Have
been unable to reach you by radio. We are flying at 1,000 feet,” she said.

Earhart's final inflight radio message occurred a hour later, at 08:43.

“We are on the line 157 337. We will repeat this message. We will repeat
this on 6210 kilocycles. Wait,” she said.

According to TIGHAR, the numbers 157 and 337 refer to compass headings --
157 degrees and 337 degrees -- and describe a navigation line that passed
not only Howland Island, the target destination, but also Gardner Island,
now called Nikumaroro.

This uninhabited atoll in the southwestern Pacific republic of Kiribati is
where TIGHAR believes Earhart and Noonan landed safely and ultimately died
as castaways.

According to TIGHAR's hypothesis, Earhart would have used the aircraft's
radio to make distress calls for several days until the plane was washed
over the reef and disappeared before Navy searchers flew over the area.

TIGHAR built a detailed catalog and analysis of all the reported post-loss
radio signals, and selected the credible ones based on their frequencies.

Transmissions from Earhart's Electra (NR16020) were possible on three
primary frequencies: 3105 kHz, 6210 kHz and 500 kHz. For the latter,
however, there were no reported post loss signals.

On her world flight, Earhart transmitted on 3105 kHz at night, and 6210
kHz during daylight, using her 50-watt WE-13C transmitter.

The Itasca transmitted on 3105 kHz, but did not have voice capability on
6210 kHz.

Under favorable propagation conditions, it was possible for aircraft
operating on the U.S. west coast at night to be heard on 3105 kHz in the
central Pacific. Indeed, the Itasca reported hearing such signals on one
occasion.

There were three 50-watt Morse code radio stations in Nicaragua which
could be heard on a receiver tuned to 3105 kHz, but the stations sent only
code, not voice.

Moreover, all transport aircraft in the area used assigned route
frequencies, instead of 3105 kHz.

"Therefore, other than Itasca, Earhart’s Electra was the only plausible
central Pacific source of voice signals on 3105 kHz," said Gillespie.

Although several of the analyzed post-loss signal reports were determined
to be hoaxes, Gillespie ruled out the hypothesis of an illegal transmitter
"given the numerous constraints militating against successfully
perpetrating a signal transmission hoax."

"We do not really have hoax transmissions but rather reports from people
who, for whatever reason, claimed to have heard something they did not
hear," Gillespie said.

To make multiple transmissions, the Electra plane needed to run the
right-hand, generator-equipped engine to recharge the batteries.

"The safest procedure is to transmit only when the engine is running, and
battery power is required to start the engine," said Gillespie. "To run
the engine, the propeller must be clear of obstructions, and water level
must never reach the transmitter."

To verify the hypothesis that the plane landed on Nikumaroro's reef,
TIGHAR researchers analyzed tidal condition on the island from 2 to 9 July
1937, the week following Earhart disappearance.

It emerged that transmission of credible signals occurred in periods
during which the water level on the reef was low enough to permit engine
operation.

According to Gillespie, at least four radio signals are of particular
interest, as they were simultaneously heard by more than one station.

The first signal, made when the pilot had been officially missing for just
5 hours, was received by the Itasca, and two other ships, the HMS
Achilles, and the SS New Zealand Star.

The Itasca logged “We hear her on 3105 now - very weak and unreadable/
fone” and asked Earhart to send Morse code dashes.

The Achilles did not hear “very weak and unreadable” voice, but heard
Itasca’s request and heard dashes in response. The SS New Zealand only
heard the response dashes.

In other cases, credible sources in widely separated locations in the
U.S., Canada, and the central Pacific, reported hearing a woman requesting
help. She spoke English, and in some cases said she was Amelia Earhart.

In one case, on July 5, the U.S. Navy Radio at Wailupe, Honolulu heard a
garbled Moorse code: “281 north Howland - call KHAQQ - beyond north --
won’t hold with us much longer -- above water -- shut off.”

At the same time, an amateur radio operator in Melbourne, Australia,
reported having heard a "strange” code which included KHAQQ, Amelia's call
sign.

According to Gillespie, the re-analysis of the credible post loss signals
supports the hypothesis that they were sent by Earhart’s Electra from a
point on the reef at Nikumaroro, about ¼ mile north of the shipwreck of
the British freighter SS Norwich City.

"The results of the study show a body of evidence which might be the
forgotten key to the mystery. It is the elephant in the room that has gone
unacknowledged for nearly seventy-five years," said Gillespie.

>From Chuck,

-John

=================