We continue with the conclusion of Paul Rafford Jr.’s “Amelia Earhart – Some Unanswered Questions About Her Radio Communication and Direction Finding” This analysis appeared in the September 1993 issue of the AES Newsletters. Boldface emphasis mine throughout; underline emphasis in original AES Newsletters version.
“Amelia Earhart – Some Unanswered Questions About Her Radio Communication and Direction Finding” (Part II of two.)
by Paul Rafford Jr.
June 22, 1993
Why was the Howland direction finder never able to get bearings on Earhart?
The reasons here are several fold. Primarily, it was because Earhart never stayed on the air long enough for an operator to take a bearing. But, even if she had stayed on longer, the combination of her low transmitting power with the inadequacy of the jerry-rigged aircraft DF on Howland, would have limited its range to less than 50 miles. In other words, on a clear day she could have seen the island before the island could have taken a bearing on her.
The questions that arise out of this fiasco are:
1) Why did whoever organized the project of setting up the direction finder on Howland not know of its extreme limitation?
2) Why did Earhart, supposedly a consultant to the government on airborne direction finders, never stay on the air more than seven or eight seconds?
Why did Earhart ask for 7500 kHz [kilohertz] in order to take bearings on the Itasca, considering it could not be used with her direction finder?
Supposedly, “7500” came about through Earhart’s ignorance of the two different designations for radio channels. It has been theorized that she confused 750.0 meters with 7500 kHz. Of course, 750.0 meters is 400 kHz, a bona fide beacon frequency, while 7500 kHz is 40 meters.
It would appear that not only did she get meters and kilocycles mixed up but she overlooked the decimal point.
Bob Lieson, a former co-worker of mine had done a stint on Howland Island as radio operator shortly after Earhart’s disappearance. I asked him if the Itasca might have used 7500 kHz for any other purpose than to send dashes for Earhart. “Oh yes,” he replied, “We used 40 meters for contact with the Coast Guard cutters when they were standing off shore.”
This brings up two questions:
1) Could it have been that Earhart was not confusing meters and kilocycles but knew ahead of time that 7500 kHz was the Itasca’s link with Howland so would be available on call?
2) Why would Noonan, both a navigator and radio operator, let Earhart make the potentially fatal mistake of trying to take bearings on 7500?
Why did Earhart not seize on the one occasion where she heard the Itasca and knew it was hearing her, to try and establish communication with the crew?
This is the most incredible part of the Earhart saga. At 1928 GMT she announced, “Go ahead on 7500 kilocycles.” Then, at 1933 GMT she announced, “We received your signal but unable to get a minimum.” Supposedly, she is hopelessly lost and about to run out of gas. Now, after searching for Howland for over an hour, for the first time she is hearing the Itasca and knows the ship is hearing her. Does she breathe a giant sigh of relief because she has finally made contact with the crew? Of course they are using code but Noonan is a radio operator and can copy code while replying to the ship by voice on 3105 kHz.
No! Instead of desperately trying to keep in contact, Earhart is not heard from for over forty minutes. When she returns to the air it is only to make one brief, last transmission. She declares she is flying north and south on a line of position 157-337 and will switch to 6210. The Itasca never hears her again.
The Mysterious Post-Flight Radio Transmissions
What was the source or sources of the mysterious signals heard on Earhart’s frequencies that began just hours after her disappearance and lasted for several days?
During the hours and days immediately following Earhart’s disappearance, various listeners around the Pacific heard mysterious signals on her frequencies.
Ten hours after the Itasca last heard her, the crew of the HMS Achilles intercepted an exchange of signals between a radiotelephone station and a radiotelegraph station on 3105 khz. The telephone station requested, “Give us a few dashes if you get us.” The telegraph station replied with several long dashes. The telephone station then announced, “KHAQQ, KHAQQ.” (Earhart’s call letters).
Believing they were hearing the plane safely down somewhere, the Achilles sent the U.S. Navy a message to that effect. However, in its reply, the Navy denied this possibility.
Two hours later, Nauru Island heard the highly distorted voice of a woman calling on 6210 khz. They reported that, although they could not understand the words, the voice sounded similar to Earhart’s when she had passed by the island the night before. However, this time there was “– no hum of engines in the background.”
Meanwhile in Los Angeles, Karl Pierson and a group of his radio engineering colleagues set up a listening watch on Earhart’s frequencies. During the early morning hours of July 3rd, they heard SOS calls on 6210 kHz both voice and telegraph. Of particular interest was the fact that the voice was a woman’s. However, neither call included enough information to identify the plane’s position or status.
The Pan Am stations at Wake, Midway and Honolulu managed to pick up a number of weak, unstable radio signals on Earhart’s frequencies and take a few bearings. But, the stations never identified themselves or transmitted any useful information.
Despite his failure to get bearings earlier, the Howland operator got a bearing on a fairly strong station shortly after midnight on July 5th. It indicated the transmitter was either north northwest or south southeast of Howland. But, again there was no identification or useful information from the station.
The question that arises here is, were the distress calls heard by Karl Pierson and his group authentic? If they were, why did the calls not include more information? If they were not, who would have sent them and why?