Today we present the conclusion of Almon Gray’s “Amelia 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  According to an unpublished manuscript by the late Capt.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:

VOICE HEARD FAIRLY STRONG SIGS STRENGTH TO S3 0843 0854 GMT 48.31 METERS [6210 kcs] SPEECH NOT INTERPRETED OWING BAD MODULATION OR SPEAKER SHOUTING INTO MICROPHONE BUT VOICE SIMILAR TO THAT EMITTED FROM PLANE IN FLIGHT LAST NIGHT WITH EXCEPTION NO HUM ON PLANE IN BACKGROUND.

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 signal” several 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.