Gray’s “Amelia Didn’t Know Radio” Conclusion

Today we present the conclusion of Almon Gray’sAmelia Didn’t Know Radio,” which appeared in the December 1993 edition of the Amelia Earhart Society Newsletters. (Boldface emphasis mine throughout.)

THE HOWLAND ISLAND RADIO DIRECTION FINDER: Earhart obviously had misconceptions concerning the radio direction finder on Howland.  She apparently thought it was a functional equivalent of the Pan American Adcock systems that had furnished her bearings from her 3105 kcs signals during the Alameda-Honolulu flight, and she expected that the DF station would be monitoring her signals and it would take a bearing when she asked the Itasca for one.  The bearing would be passed to the ship, which would send it to her on the next schedule.  This explains why she repeatedly asked the Itasca for bearings on 3105 kcs.  She did not expect the ship to take the bearings with its own DF gear — she was counting on the Howland Island DF. 

I think there was some basis for her misconception.  After changing to an east-about route, and while the Lae-Howland leg was being studied, Earhart and Noonan suggested to the Coast Guard that a radio direction finder be set up on Howland.  According to an unpublished manuscript by the late Capt. Laurance F. Safford, U.S. Navy, (Retired) [which later became Earhart’s Flight Into Yesterday: The Facts Without the Fiction, 2003], it was Richard Black, scheduled to go to Howland in the Itasca, who arranged for the Howland DF. 

Unfortunately, Earhart did not understand the relationship between wavelength and frequency nor how to convert one to the other.

Apparently reacting to Noonan’s suggestion, he recommended to George P. Putnam, Earhart’s husband and business manager, that they borrow a high-frequency radio direction finder from the Navy.  Subsequently Black, assisted by Lt. Daniel A. Cooper of the Army Air Corps, also going to Howland in the Itasca, obtained the desired apparatus from a Navy patrol plane at Pearl Harbor and took it to Howland, where it was jury-rigged to provide a temporary DF capability.  An Itasca radioman operated it.*

*[Incorrect: Navy Radioman 2nd Class Frank Cipriani was temporarily assigned to operate the Howland Island direction finder for the Earhart flight.]

Capt. Laurance Safford, the father of Navy cryptology, who established the Naval cryptologic organization after World War I and headed it, for the most part, though Pearl Harbor. Safford’s verdict on the Earhart disaster was that the fliers “were the victims of her over-confidence, an inadequate fuel supply, bad weather, poor planning . . . miserable radio communications and probable friction between the crew.” Did Safford know more about the fliers’ fates than he ever publicly admitted?

According to Captain Safford, the apparatus was . . . a 24-volt aircraft type of loop-direction-finder similar to the one installed in Miss Earhart’s plane — possibly its twin.”  Black later described it to author Fred Goerner as an experimental model of some of the direction finders we used in the war.”  It may have been one of the three experimental receivers built by Bendix, and thus a twin to Earhart’s.  Cooper, who helped Black obtain the DF gear, wrote in his official report: “It is true that an airplane direction finder capable of working 3105 KC had been borrowed from the Navy just prior to sailing.  This was set up on Howland mainly as a standby in case the ship’s direction finder on 500 KC should go out.”

This clearly shows that Cooper, Black, and Putnam believed that inasmuch as the frequency range of the receiver included 3105 kcs, it would be able to take bearings on that frequency.  Putnam communicated frequently with Earhart and certainly would have kept her apprised of developments regarding the Howland DF: when he told her (while she was in Darwin) that the Itasca reported the DF had been installed on Howland, she had good reason to believe that en route to Howland she would be provided with bearings taken on her 3105 kcs signals just as they had been provided her by PAA on the Alameda-Honolulu flight.

She was wrong.  The apparatus undoubtedly was an excellent receiver and was capable of receiving a wide array of frequencies well above Earhart’s 3105 kcs.  For direction finding, however, it used a simple rotatable loop-type antenna, which because of the very nature of radio wave propagation, is incapable of obtaining meaningful bearings over significant distances on frequencies higher than about 1800 kcs.  On higher frequencies, signals can be heard but no steady null or “minimum” (which indicates the bearing) can be obtained.  It should have been no surprise then that the Howland DF was unable to get bearings on the plane.  The operator complained that Earhart had not transmitted signals long enough for him to take a bearing, but this was irrelevant; longer transmissions would not have helped.

Post-flight signals

  • Nauru.  On July 3 (GMT date) an operator at Nauru radio station VKT sent the following “wire note” to RCA radio station KPH at San Francisco, with the request that it be passed to the Itasca:


The Nauru operator was a professional wireless operator, well qualified to judge the quality of radio signals.  He had heard some of Earhart’s transmissions the night before and was familiar with the sound of her voice and of the cockpit background noise.  That he was able to recognize the voice but was unable to understand what was being said, and his diagnosis of probable over modulation, jibe with the reports of the wireless operator at Lae and the DF operator at Howland.  He had nothing to gain by fabricating information.  Given this — and because Earhart probably was the only woman in that part of the world transmitting voice signals on 6210 kcs,  there is a strong case for ascribing the signals to Earhart’s plane.  Since more than 12 hours had elapsed between the time the Itasca last heard the plane and the time the Nauru operator intercepted the signals, the aircraft certainly was no longer in flight The absence of the “hum” (engine noise) in the intercept tends to confirm this. 

Amelia, with Bendix Corporation rep Cyril Remmlein, and the infamous direction-finding loop that replaced Fred Hooven’s “radio compass” or “automatic direction finder.”  Hooven was convinced that the change was responsible for Amelia’s failure to find Howland Island, and ultimately, for her tragic death on Saipan.  Whether the loop itself failed the doomed fliers during their final flight remains uncertain.  See p. 56 Truth at Last for more.  (Photo courtesy Albert Bresnik, taken from Laurance Safford’s Earhart’s Flight Into Yesterday.)

  • Pan American Airways.  Shortly after Earhart became overdue at Howland, the Coast Guard requested PAA assistance in the search.  The stations at Mokapu Point, Midway, and Wake almost immediately began to monitor the plane’s frequencies consistent with available personnel, and were prepared to take bearings on any signals reasonably believed to be coming from the plane. The airline established a special radio circuit linking the three stations.  Numerous weak signals were heard but nothing of interest was picked up until July 5 (GMT).  The following is extracted from a report made by the Radio Operator-in-Charge at the Wake Island station, R.M. Hansen:

At 0948 a phone signal of good intensity and well modulated by a voice but wavering badly suddenly came on 3105.  While the carrier frequency of this signal did not appear to vary appreciably, its strength did vary in an unusually erratic manner and at 0950, the carrier strength fell off to QSA2 [2 on a scale of 0 to 5] with the wavering more noticeable than ever.  At 0952, it went off completely . . . . At 1212 [GMT 5 July] I opened the DF guard on 3105 KC.  At 1223 a very unsteady voice-modulated carrier was observed on 3105 KC appx [sic].  This transmission lasted until 1236.  I was able to get an approximate bearing of 144 degrees.  In spite of the extreme eccentricity of this signal during the entire length of the transmission, the splits were definite and pretty fair. . . . After I obtained the observed bearing, I advised Midway to listen for the signal (couldn’t raise Honolulu).  He apparently did not hear it.  This signal started in as a carrier strength of QSA5 and at 1236, when the transmission stopped it had gradually petered out to QSA2 during the intervals when it was audible.  

“The characteristics of this signal were identical with the signal heard the previous night (0948 GMT) except that at DF the complete periods  of no signal occurred during shorter intervals. . . . While no identification call letters were distinguished in either case, I was positive at that time that this was KHAQQ [Earhart’s aircraft call letters].  At this date I am still of this opinion.” 

  • Midway.  At 0638 5 July (GMT), the station heard a signal having the same characteristics, and almost certainly the same station.  The operator computed a quick bearing of 201° True, but the signal was not audible long enough to take a really good bearing and the 201° figure was labeled approximate.
  • Honolulu (Mokapu Point).  This station also heard the 3106 [sic] kcs peculiar signalseveral times.  From 1523 to 1530 on 4 July (GMT), the station attempted to get a bearing; the signal was weak and shifting, and only a rough bearing was obtained.  It was logged as 213° but was by implication a doubtful bearing.  Sometime between 0630 and 1225 GMT another bearing was attempted.  The log describes it thus:Signals so weak that it was impossible to obtain even a fair check.  Average seems to be around 215 degrees — very doubtful bearing. It is obvious that the bearings from Honolulu were much inferior to those taken from Wake and Midway; they are useful mainly that the unknown station continued to function.

Fred Noonan at Java, June 1937.

Few paid any attention to these intercepts at the time because no one was aware that Earhart’s radio signals had been abnormal.  Had it been known that she was having over-modulation problems more attention probably would have been given them because the wavering in the carrier strength is consistent with a varying degree of over modulation rapidly increasing and decreasing carrier power.  The gradual drop in signal strength from QSA5 to QSA2 over a span of 13 minutes is consistent with the further discharge of an already partially discharged storage battery power supply.  The peculiar signals on 3105 kcs heard by Wake, Midway and Honolulu may very well have come from the Earhart plane, and it is likely that the radio bearings taken on these signals by Wake was accurate within a degree or so.  The one from Midway may have had a slightly larger error.

FREDERICK J. NOONAN: From personal observation, the writer knows that as of late 1935 Noonan could send and receive plain language at slow speeds, around eight to 10 words per minute.  Recent research by Noonan biographer Michael A. Lang has revealed that circa 1931 Noonan held a Second Class Commercial Radio operator license issued by the Radio Division of the U.S. Department of Commerce.  The license, which was valid for two years, certified that the holder was capable of:Transmitting and sound reading at a speed of not less than 16 words a minute Continental Morse in code groups and 20 words a minute in plain language.

CONCLUSIONS: Earhart failed to reach Howland, because she was unable to use the electronic aids that had been set up to help her find the Island. Her inability to hear the Itasca on the communication channel precluded any possibility of receiving aid from the Howland DF.  Therefore she was completely dependent upon bearings she could take on the Itasca beacon with her own DF.

When it became evident that she would get no help from the Howland DF, Earhart prepared to take bearings on the Itasca’s beacon.  She tuned in the beacon on her DF and heard the signals clearly.  When she tried to take a bearing, however, she was unsuccessful because she could not get a “minimum.”  She had no idea why she could not get a bearing, nor did she know what to do to improve the situation.  Lack of two-way communication with the ltasca prevented her from getting advice from the ship.  Apparently, after a final unsuccessful attempt to have a bearing taken on her 3105 kcs frequency, she gave up on radio navigation and left the area.

The direct cause of the flight’s failure was Earhart’s unwitting error in designating 7.50 Mcs as the beacon frequency for the Itasca.

The probable cause for the antenna system failure was malfunctioning of the “send-receive” relay, located physically in the transmitter unit, which left the receiver without an antenna.  The relay probably malfunctioned because of damage by lightning or heavy static discharge.  (End of  Almon Gray’s “Amelia Didn’t Know Radio.”)

As a layman whose technical knowledge and ability barely extends to mowing the lawn, something that’s becoming increasingly difficult as I progress into my 70s, Almon Gray’s radio sophistication boggles my mind.  But Gray’s entire, comprehensive radio analysis is based on one key assumption, which is that Amelia and Fred were actually trying to reach Howland Island.  Without that one overriding element, Gray’s scenarios become strictly academic.  

Over decades of study and discovery since the disappearance of Amelia Earhart, many researchers have concluded that Howland Island was not the real destination of her final flight, but was just another official piece of a larger puzzle, whose intricacies have yet to be definitively unraveled to reveal the true picture.  

9 responses

  1. I believe it’s important to get some facts straight, lest your readers and others pass on misinformation which seems to be pretty common these days.

    Amelia Earhart had no idea the Itasca was carrying a portable high frequency DF unit that would be set up on Howland Island and used to capture her radio signals. Nor was it at her or Noonan’s suggestion, and it wasn’t Black’s suggestion either. The opposite happened. An unidentified Navy lieutenant from Pearl Harbor telephoned Black and asked that a “breadbox” size DF be set up on Howland Island. He even told Black the Navy would supply a qualified operator. When Commander Thompson of the Itasca heard about the portable DF and told the Navy would supply an operator, he was livid. For years, Fred Goerner tried to get the name of this unknown lieutenant but with no success.

    Let’s make something else clear: Amelia knew next to nothing about radios and wouldn’t know a Pan Am Adcock system if it slapped her in the face. When it came to radios, she was clueless. Since I’m on a roll, I’ll even say if anyone believes anything Laurence Safford wrote, they believe in the tooth fairy.

    As for correspondence from Putnam to his wife telling her a portable DF had been installed on Howland Island – where did that come from?

    The discussion centering around the signals received at Nauru, Wake, Midway, and Honolulu are correct, although, I believe Noonan held a third-class radio operating permit, a necessary license in order to pilot as plane in those days. (Noonan was a pilot). He admitted more than once he was a “bum telegraph operator” and couldn’t transmit or receive more than a few words a minute, although I find that remark a little reckless. Even a few words of Morse code a minute would have made all the difference in the world.

    Les Kinney


    1. William H. Trail | Reply


      I don’t know what significance we should assign to this, if any, but since you mention direction finding and Safford in the same comment I thought I’d share it for what it’s worth.

      “In 1936, Safford returned from sea duty (cruiser Portland, 1933; battleship New Mexico, 1934-1935) to again take charge of “his” organization. But now he was not only just running the Research Desk [italic]within[/italic] the CSS; he was moved up to run [italic]all[/italic] of OP-20-G, now called the Communications Security Group.

      He modernized the existing equipment, adapted it to teletype and other rapid means of communication, developed various concealment and scrambler systems, started a program of miniaturization, and eliminated practically all the old paper-and-pencil systems.

      Also during this period, one of his principal accomplishments, before the outbreak of the war, was the establishment of the Mid-Pacific Strategic Direction-Finding Net — and of a similar net for the Atlantic; where it was to play a role of immense importance in the Battle of the Atlantic against the U-boats.”

      Source: “U.S. Navy Codebreakers, Linguists, and Intelligence Officers Against Japan, 1910-1941 (2016) Roman & Littlefield, by Captain Stephen E. Maffeo, USNR (Ret.) Page 145.

      All best,



  2. Almon Gray presents an in depth analysis of Amelia’s radio capabilities and likely problems, as well as her own difficulties communications.

    From the reports cited by Gray of experienced radio operators who received her signals at Wake, Midway, and Honolulu, it would certainly appear that the Electra made a landing some where on an available island, rather than a water ditching at sea.

    These official radio stations reported hearing what they believed were her transmissions as late as 5 July 1937 – some 3 days after the Electra would have no longer been airborne.

    Not noted by Gray were numerous other reports by amateur ham radio operators who also claimed to have heard post flight time signals.

    Absence of engine noise and erratic wavering and fading of her signal toward the end of her transmissions would indicate that she was powering her radio solely on battery.

    If, in fact Amelia and Fred made a successful island landing, and were transmitting radio signals, it could likely be concluded that Japanese forces in the area would also have heard them and fixed their position.


  3. It is tragic to think that an error in judgment could have cost these two their lives- that is if the supposed ignorance was intentional and they never meant to be tracked


  4. William H. Trail | Reply

    Greetings to All:

    The following information regarding radiotelephone/radiotelegraph operator’s license qualifications comes from “Aeronautic Radio” (1939) The Ronald Press Company, 3rd Ed., by Myron F. Eddy, Page 22.

    “The applicant for a second class radiotelephone operator’s license will be examined in the following subjects:

    1. Radio communications laws and regulations.

    2. General principles of electricity; operation and care of storage batteries; power supply apparatus.

    3. The theory, adjustment, operation, and care of radiotelephone transmitters; receivers, including a diagram of an installation of both receiver and transmitter.

    The examination for third class (radiotelephone) deals mostly with regulations* For a third class radiotelegraph, a code test must be passed, otherwise this examination is much the same except that the diagram of a radiotelegraph transmitter must be drawn and the operation of the set explained.

    * Specifically ten questions based on the radio provisions indicated in Title III, Part I, Title V and Title VI of the Communications Act of 1934, as amended.

    An applicant desiring to be examined for radio operator’s license reports in person to the nearest radio inspector and fills out two application forms. He is then given a written examination in sections, each section consisting of from five to ten questions. A percentage of 75 consists of a passing mark. In case of failure the applicant may not be reexamined for ninety days.”

    All best,



  5. Off topic here; a while back I posted a link to film footage of Aslito Field June 1944 from the site Critical Past. I don’t recall if I searched that site for AE at the time, but there are numerous film clips on there (most do not have sound). One features AE, GP, and Paul Mantz weighing and inventorying items for the RTW flight, including un-zipping a bag and inspecting the life raft, and Amelia demonstrating the “note on the pole” method with Fred. Another has footage of their return from Hawaii after the crash (Harry Manning is not all smiles). Lots of other good stuff to find there.


    1. William H. Trail | Reply


      Since you mentioned it, it has never made sense to me why AE’s $80,000.00 ($1,684,345.32 in today’s money), modern, Lockheed Electra 10E Special, the so-called, “Flying Laboratory,” wasn’t equipped with a simple intercom system for communicating between the cockpit and navigator’s station. Even in 1937, hardly the Dark Ages, an intercom for the Electra couldn’t have weighed that much, and even though it would have certainly weighed more than a simple bamboo pole, the ease of communication between pilot and navigator would have undoubtedly been worth every extra ounce of weight.

      All best,



      1. William,

        I agree. Voice communication is much more efficient that hand written messages (which is why I don’t like text messaging).

        I noticed in the clip I included above, the cockpit hatch was hinged near the center of the fuselage (which makes sense); in another clip (below) the hatch was hinged above the side window and opened outward, making entry more difficult (the loop was not installed either).

        Also, that clip has sound and states “…the theory has always been that she wandered off course and landed near Truk where the Japanese had secret military installations, she may have been executed”.


  6. I may have tried to put this link in the wrong story. Here it is again.

    This is a well done video that complements Gray’s remarks. It contains the speculation that Amelia may have broken off her under-fuselage antenna on the Lae take-off which would account for her not hearing the Itasca.
    I also like the Betty Klenck interview which gives her a lot of validity. Her notes sound just like many can picture her landing on a slightly submerged reef with the tide coming in or the plane slowly taking on water. I tend to believe her account. I also have always thought she was hearing Nonouti, not Norwich City. She heard Fred saying “Marie” or Mary which was his wife’s name. How would Betty know that?
    Also in the intelligent commentsone man’s father, a commercial pilot thinks Amelia was very unqualified to take such a risky trip around the world.
    There is another remark which states that someone thought there was a record of the Norwich City rescuers leaving a large cache behind containing water & food supplie s meaning Amelia and Fred should have survived a Nikumaroro stranding. I think I heard this story, too, long ago.
    The narrator believes the loss of Manning (and Mantz) was serious enough that it more or less precluded her success. Perhaps they both took a dim view of Amelia’s qualifications both as a pilot and as a competent organizer of such a serious undertaking. Why not learn a little Morse code? I would, if my life depended on it.
    I just checked up on Winslow Reef, it says minimum depth is 11 meters, meaning she could not actually land on it, too deep.


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