Think it is plane? Unidentified radio signals associated with the Earhart Mystery

On the morning of July 2, 1937 the Coast Guard cutter Itasca was on station off Howland Island, a tiny speck in the Pacific midway between Lae, New Guinea and Hawaii.  Since about 2:45 a.m., the Itasca’s radio room had been receiving messages from an inbound airplane that had taken off from Lae the previous morning.  On board were Amelia Earhart Putnam and her navigator Fred Noonan, engaged in an around-the-world flight that had begun in Oakland, California on May 20th.

The World Flight

Earhart had planned her World Flight as a series of  "legs," each one requiring 20 hours or less of flying time.  This had to be done to accommodate the cruising range of her plane, a Lockheed twin-engine "Electra" that had been specially modified for long distance flying.  When flown at its "economical" cruising speed of 150 mph, it could stay aloft for more than twenty-four hours.  By limiting her flights to no more than 20 hours, Earhart would always maintain an emergency fuel reserve of at least four hours.

Flying the distance between New Guinea and Hawaii was clearly beyond the Electra’s fuel capacity.  However, by good fortune, the United States had recently colonized three small, desolate islands near the equator that were ideally located for use as a mid-point refueling stop.  Largely to accommodate Earhart, several of her highly-placed friends in the United States Government had arranged for a small airfield to be hastily built on Howland, one of these three islands.  There, she would be able to land, refuel, and rest up before continuing on to Hawaii.  Earhart’s Washington friends had also arranged for the Coast Guard to order the Itasca to proceed from the West Coast of the United States to Howland to provide radio support and act as "plane guard" when she arrived there.

The Flight to Howland Island

The 2,500-mile flight from Lae to Howland was the longest and most difficult leg of the entire journey.  It would require Fred Noonan to navigate over open water to an island that was only 1.5 by 0.7 miles across and with no prominent landmarks.  However, while serving as lead navigator for Pan American Airways in 1935-36, he had helped to develop procedures for navigating the famous Pan Am "Clippers" vast distances to small Pacific island destinations.  For the Howland flight, his plan was to use celestial navigation to keep the flight on course until it was within range of the Itasca. Then, the plane and the ship would use their radio direction finding equipment to locate one another and determine the specific course needed to reach Howland safely.

Last Confirmed Transmission 

However, as Earhart arrived in the vicinity of Howland Island, serious problems arose.  Itasca’s attempts to call Earhart and establish two-way voice communications were not successful.  Since neither Earhart nor Noonan were proficient in Morse code, they were not able to understand the messages that Itasca was sending to them in code.  Even more serious, the Itasca was unable to obtain bearings from Earhart’s radio transmissions.

At 0742 local time Earhart radioed: "KHAQQ [her plane’s call letters] calling Itasca we must be on you but cannot see you, but gas is running low, been unable to reach you by radio, we are flying at 1000 feet."

Then at 0800: "KHAQQ calling Itasca we received your signals but unable to get a minimum.  Please take bearing on us and answer 3105 [Earhart’s night time frequency] with voice."

Again Itasca tried to take a bearing on Earhart’s transmission and failed.

And then at 0843: "KHAQQ to Itasca we are on the line 157 337 will repeat message, we will repeat this on 6210 KCS wait."

This message, received some twenty hours and thirteen minutes after Earhart had taken off from Lae, is the last one that can be confirmed as having comefrom the World Flight.

After repeatedly attempting to establish contact with Earhart without success, the Itasca got underway at 10:40 a.m. local time to begin search operations.  Although no one knew for certain where Earhart’s plane was, a cloudbank could be seen about thirty to fifty miles off to the northeast.  Since the sky was clear in all other directions, it was assumed that Earhart and Noonan had failed to see the island because they were lost somewhere in that cloudbank.  The Itasca set a course for the northeast and proceeded there with all due haste.

On the line 157 337

In her last transmission, the only indication that Earhart had given as to her intentions was that she on a line 157 337.  This meant that she was either flying on a heading of 157 degrees or its reciprocal 337 degrees.  If Earhart had been north of Howland Island and was steering a course of 337, there was nothing ahead of her but open ocean for thousands of miles.  However, if she had been south of Howland and was steering a course of 157, she was within a few hours flying time of the Phoenix Islands, a cluster of small, mostly uninhabited islands under British authority.  The two islands closest to this 157 course were McKean and Gardner.  Both were uninhabited and neither had a landing field.  Gardner Island, however, was surrounded by a smooth, flat coral reef that, in an emergency, could be used to make a forced landing.

The Navy Becomes Involved

By now, word of Earhart’s flight being overdue had reached Rear Admiral Orin G. Murfin, Commandant of the Fourteenth Naval District, based in Pearl Harbor.  Admiral Murfin immediately dispatched a PBY Catalina flying boat to Howland Island to assist with the search effort.  (This flight was later forced to return due to adverse weather conditions encountered while in route.)

The battleship USS Colorado (which had onboard three catapult-launched floatplanes) was ordered to leave from Pearl Harbor on July 3rd and proceed to Howland to join in the search. 

At North Island Naval Air Station in San Diego, the aircraft carrier USS Lexington and her four destroyer escorts were ordered to make ready to get underway for Howland. In less than 24 hours, the necessary stores and supplies for a four-week cruise were gathered up and loaded.  When the Lexington left San Diego on July 5th, it carried 62 planes capable of searching a vast area.

Evening, Day #1

While the Itasca searched to the north of Howland, her radio room continued to monitor Earhart’s 3105 kilocycles voice frequency.  At exactly six o’clock in the evening, a weak signal was heard behind the static.  Although no words could be made out, it was assumed that it was a message from Earhart.  Itasca immediately responded by voice and in code, but there was no reply.  As the sun sank below the horizon and reception conditions improved, the voice was back, very weak and unreadable.  The Pan American Airways station on Mokapu Point in Hawaii also heard a "steady carrier on 3105 – no modulation, very weak."  If the signals were coming from Earhart, it meant that her plane had to be on land since it could not transmit while in the water.

At 6:30, Itasca requested Earhart to send a series of long dashes.  Following this request, and a thousand miles to the southeast, the New Zealand Navy cruiser HMS Achilles heard intermittent transmissions on 3105, which it interpreted as dashes.  At about this same time, the steamer SS New Zealand 1200 miles from Howland heard dashes on 3105 kilocycles. Itasca also heard these signals as well as the word "Earhart."

Itasca again called the plane in both voice and code, and this time a man’s voice was heard "still distorted and unreadable."  Since the Itasca had never been informed that Fred Noonan was on board the flight, this transmission was logged as "phone signals definitely not Earhart."  At about 7:00 p.m. the garbled voice transmissions stopped.

Exactly at 8:30 p.m., government radio operators in Hawaii heard dashes on Earhart’s other frequency of 6210 kilocycles.  Still monitoring 3105, Itasca didn’t hear this transmission.  Thirty minutes later, however, Itasca heard a weak signal on 3105 that was unreadable.

A thousand miles to the west on the British island of Nauru, a radio operator monitored "fairly strong signals" on 6210 kilocycles.  Once again, speech could not be interpreted because of bad modulation. 

At about 9:30 p.m., the voice signals stopped.

Evening, Day #2

In Oahu, the Coast Guard’s Hawaiian Section enlisted the aid of two of Honolulu’s major commercial radio stations KGU and KGMP.  It was known that Earhart was familiar with both of these stations from her previous visits to Hawaii.  On the chance that she might be listening to one of them for news of rescue efforts on her behalf, these stations were asked to broadcast a special message to Earhart.  If she replied, direction-finding receivers in Hawaii, Midway Island, Wake Island and San Francisco would attempt to obtain bearings on these signals to determine where they were coming from.  Itasca was instructed to "not, repeat not, use 3105 or 6210 kilocycles next two nights to permit absolute check on authenticity of calls and to permit monitoring of above frequencies by use of directional antennae."

At 10:00 p.m. in Honolulu (9:00 p.m. aboard Itasca) KGU made a special broadcast on its regular frequency, asking Earhart to reply.  Shortly afterwards, a faint carrier on 3105 was heard in Hawaii by Pan American and by the Coast Guard.  Since no one had informed Itasca about the special KGU broadcast, her radio room was not initially monitoring 3105.  When it did start listening, however, it picked up a weak carrier.  KGMB made special broadcasts to Earhart at 10:30 p.m. and at midnight.  In Hawaii, Pan American, the Coast Guard, and the U.S. Navy radio station at Wailupe heard faint signals.  All told, about four hours of intermittent receptions on Earhart’s frequency were heard by Itasca, the Coast Guard, the Navy, and Pan American.   

"I Got Miss Earhart"

Five thousand miles away in Rock Springs, Wyoming, 16-year-old Dana Randolph was listening to a commercial radio set that had shortwave bands.  The set was connected to a new and special antenna that Dana had just erected.  At about 8:00 a.m. on the morning of July 4th, while listening at approximately 16,000 kilocycles, he heard a woman say, "This is Amelia Earhart.  Ship on a reef south of the equator.  Station KH9QQ [sic]."  The signal then died away.   Dana and his father reported what he had heard to the local Department of Commerce radio operator.  The operator realized that the frequency Dana had been monitoring was most likely 15,525 kilocycles, the fifth harmonic of 3105.  From personal experience, the operator knew that freak receptions like this one were possible on harmonics.  He immediately forwarded this information on to Washington.

Evening, Day #3

At 8:00 p.m. on the evening of July 4th, KGMB in Honolulu began broadcasting the following special message at intervals of 15 minutes: "to Earhart plane.  We using every possible means establish contact with you.  If you hear this broadcast, please come in on 3105 kcs.  Use key if possible, otherwise voice transmission.  If you hear this broadcast, turn carrier on for one minute so we can tune you in, then turn carrier on and off four times, then listen for our acknowledgement at 0645 GCT."

As the evening wore on and reception conditions improved, more stations began to hear the replies.  The Pan American stations on Mokapu Point, Midway Island and Wake Island were able to take directional bearings that placed the source of the signals as somewhere in the area of McKean Island and Gardener Island in the Phoenix Island group.  Based on this new information, the Navy concluded that, after failing to find Howland, Earhart and Noonan had turned southeast in an attempt to reach the nearest land.  (This theory was consistent with the "we are on the line 157 337" message received from Earhart during her last transmission.  Also, since Earhart’s radio would only work if the plane was on land, it stood to reason that she was most likely on one of the Phoenix islands.)  Accordingly, the Colorado was ordered to change course and proceed to and conduct an air search of the Phoenix Group.  Incredibly, no one bothered to inform Itasca that the unknown signals received on Earhart’s frequency appeared to have originated in the Phoenix Islands.  Itasca continued to search the waters north of Howland Island. 

Betty’s Notebook

In St. Petersburg, Florida, 15-year-old Betty Klenck was listening to the family’s large console radio.  Her father, an amateur radio buff, had invested in the best radio he could afford and had it connected to a special antenna that he had strung up in the backyard.  That afternoon, as Betty listened, she doodled and jotted down bits of information in a notebook that she always kept close by the set.  While tuning through the shortwave bands, she heard a woman who sounded quite upset say, "This is Amelia Earhart." For the next hour and forty-five minutes, Betty heard a woman and a man trying to send what sounded like distress calls.  At times, the man sounded irrational such as from sickness or an injury.  Both sounded like they were under extreme physical and emotional stress.  Although the jumble of words, letters and numbers coming from the radio’s speaker were too fast for Betty to take down verbatim, she copied down as much of what she heard as possible.  When her father returned home from work, he heard the last part of this broadcast.  Convinced that it was genuine, he drove to the St. Petersburg Coast Guard station to report what he and his daughter had heard.  There, the duty officer assured him that the Coast Guard already had a ship in the area and was on top of the situation.   

Years later, Earhart scholars who examined this notebook would focus on one of the seemingly meaningless sentences that Betty had copied down: "George, get the suitcase in my closet."  Earhart kept her most personal, private papers inside of a briefcase that was stored in a closet in her North Hollywood, California home. Over the years, and on several occasions, she had instructed family members and her husband George Putnam to burn the contents of this briefcase should anything ever happen to her.  Betty, of course, had no way of knowing this, and this one brief sentence provides strong evidence that, like Dana Randolph, she had most likely heard a radio transmission from Amelia Earhart on a harmonic.

Evening, Day #4

In contrast to the previous three evenings, almost nothing was heard on 3105 on the fourth night after Earhart and Noonan had disappeared.  By this time, both fliers would have been suffering from dehydration and lack of food, and were perhaps in need of medical attention.  The Colorado was due to arrive in the Phoenix Islands the next day, and it was hoped that an air search would quickly be able to locate the missing pair.

Air Search of the Phoenix Islands

Beginning on July 7th, the Colorado’s three aircraft under of the command of Senior Aviator on board Lieutenant John O. Lambrecht flew search operations in the Phoenix Islands.  A fly-over was made at each island, and a landing was made in the lagoon at Hull, the only island of the group that was inhabited.  The search lasted four days and covered some 25,490 square miles.

Lambrecht’s fly-over of Gardner Island occurred on July 9th.  It was later estimated that the total time he spent over the island was about 10 minutes.  In a report later submitted to the Bureau of Naval Aeronautics, this is how he described what he had observed there:

"Gardner is a typical example your south sea atoll . . . a narrow, circular strip of land . . . surrounding a large lagoon.   Most of this island is covered with tropical vegetation with, here and there, a grove of coconut palms.  Here signs of recent habitation were clearly visible but repeated circling and zooming failed to elicit any answering wave from possible inhabitants and it was finally taken for granted that none were there." 

In his report, Lambrecht also speculated that, " it is not hard to believe that a forced landing could have been accomplished [on Gardner’s reef] with no more damage than a good barrier crash or a good wetting."

Years later, when asked what he meant by "signs of recent habitation," Lambrecht replied, "Markers of some kind."

In his official report, the commanding officer of the Colorado Captain Wilhelm F. Friedell, stated that "No one was seen on either Gardner Island or McKean Island," and "(n)o dwellings appeared on Gardner or any other signs of inhabitation."  

The inconsistencies between the Lambrecht and Friedell reports continue to baffle Earhart researchers to this day.

On July 12, the Lexington and her destroyers arrived and took over the search, which now shifted away from the Phoenix Group to the open waters north and west of Howland.  In all, some 151,556 square miles of trackless ocean were searched by the Lexington’s pilots without success.

Final Verdict

On July 18th, the search was officially called off.  The general opinion was that the plane had probable run out of gas, gone down at sea, and sunk without a trace. The post loss radio signals were dismissed as misunderstandings or outright hoaxes. 

Bones on Gardner Island

Gardner Island (later renamed Nikumaroro) was colonized by people from the Gilbert Islands in 1938.

In September 1940, Gerald B. Gallagher, the young officer in charge on Gardner radioed his superiors in Suva that the skull and partial skeleton of a castaway had been discovered in a remote area of the island and in a place where it was unlikely to have been seen by an air search.  Close to the body was found a woman’s walking shoe, an empty bottle, and an empty sextant box.  Also nearby were the remains of a fire, as well as turtle and bird bones, indicating that the deceased had survived for a time after coming ashore.  Realizing that these might be the remains of Amelia Earhart, Gallagher radioed his superiors for instructions.  He was told to carefully search the area where the bones had been found and then send all bones and artifacts recovered to the High Commission Office in Suva.  He was also told keep this matter "strictly secret for the present."  In January 1941, the bones, sextant box, shoe, etc. were shipped to Suva.  There, in April 1941, the bones were examined by Dr. D. W. Hoodless, Principal of the Central Medical School in Suva.  Dr. Hoodless’ official report contains detailed measurements of the skull and bones, and ventured the cautious opinion that they might be those of someone of European or mixed European descent.   After the Hoodless report was submitted and acknowledged, it was carefully filed away and forgotten.  There is no evidence that the High Commission Office in Suva ever contacted American authorities with news of the discovery.  

A New Search Effort Begins

In 1988, The International Group for Historic Aircraft Recovery (TIGHAR) opened its own investigation into the Earhart mystery.  TIGHAR’s hypothesis was that stronger than normal winds had caused Earhart’s plane to drift off course so that it ended up south of Howland Island.  When the island was not sighted visually, and when radio bearings could not be obtained from the Itasca, Earhart and Noonan had turned southeast, flying on a course of 157 degrees towards the Phoenix Island Group.  (Hence the "we are on the line 157 337" message received during Earhart’s last transmission.)  They eventually reached Gardner Island and made a forced landing on its smooth, flat coral reef.  After attempting to send radio distress calls, Earhart and Noonan waded ashore and survived for a time as castaways. 

To prove this hypothesis TIGHAR’s network of volunteer investigators began seeking out and reexamination historical records to look for facts that would support a Gardner Island landing.  Among the documents they eventually uncovered were the Freidell and Lambrecht reports of the air search of Gardner Island, the radio logs of the Itasca, Betty Klenck’s notebook, transcripts of Gallagher’s radio messages about finding the bones on Gardner Island, and Dr. Hoodless’ official report with detailed measurements of the skull and bones that Gallagher had found.  TIGHAR researchers journeyed to Suva in an attempt to locate the partial skeleton and the artifacts recovered on Gardner Island.  [To date, the whereabouts of these items remains unknown.] TIGHAR also sponsored several scientific expeditions to Gardner/Nikumaroro Island to search for identifiable pieces of Earhart’s plane and for personal items that can be linked to Earhart and Noonan.  These expeditions conducted archaeological surveys in a manner similar to those being conducted at military crash sites in Vietnam to locate and identify the remains of U.S. aircrews still officially listed as "Missing in Action."  While a number of artifacts have been recovered, none of these has proven to be the "smoking gun" needed to resolve the mystery once and for all.  However, more expeditions are planned and archival research is on-going.  With each new piece of information that comes to light, we move that much closer to learning what really happened to the world’s most famous aviatrix and her navigator on July 2, 1937.

As one of the 1930’s major celebrities, Amelia Earhart received extensive coverage in newspapers, magazines and newsreels, made guest appearances on radio, and even had a brief cameo appearance in the animated cartoon The Air Race (1933.)  Her first major media appearance following her world flight was to have been as the intermission guest on the Lux Radio Theater’s broadcast of June 28, 1937.  Because she had fallen behind schedule, it was announced during the June 28th broadcast that she would be appearing on the following week’s show (the broadcast of July 5th), "if she should have arrived in time."  By the time that broadcast aired, she had already gone missing. 

Suggested Reading

By far, the best account of the radio messages associated with the Earhart mystery is contained in Finding Amelia – the True Story of the Earhart Disappearance by Ric Gillespie and published by the Naval Institute Press.  In addition to a well-researched, well-written text, the book comes with a DVD containing over 5,000 historical messages, telegrams, letters, maps, radio log pages, relevant pages from Betty’s notebook, etc.  

Those interested in learning more about the scientific search methods that are being used to help solve the Earhart mystery should read Amelia Earhart’s Shoes, by Thomas King, Randall Jacobson, Karen Burns and Kenton Spading.

ABOUT THE AUTHOR:

Eric Beheim is a life-long radio enthusiast.  A former commanding officer of a Naval Reserve Combat Camera unit based in San Diego.

Eric Beheim leads a multi-faceted career as a free-lance writer, professional musician, and owner of his own music and sound project studio. 

Born in the first wave of "baby boomers" he grew up with radio and remains a life-long radio enthusiast.  His particular interests are collecting news and commentary programs from the late 1930s and early 1940s (including World War II news), and programs that feature performances of operettas and musical theater presentations.

Read more about Eric Behiem...

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