For the first few
days, the Itasca and Capt. Thompson were in charge of search and
rescue for Earhart, and had little help from other ships. The Itasca
searched west and north, chasing down amateur and Navy messages suggesting
Earhart was down on the water. The Swan and the steamer Moorsby
helped search for a few hours north of Howland, but there was little Itasca
could do productively given almost no solid information or leads on where
Earhart went down.
Instead of providing
detailed description of the movements and radio messages received by the
Itasca and others, a synopsis of important events and areas of
search follows. Many of the details are contained in the various radio
transcripts, radio message traffic, ship logs, and reports from Capt.
cruised to the north, with a sharp lookout during the early morning hours,
but was concerned about fuel reserves. During high speed search and rescue
operations, fuel is expended faster than at most economical rate, and
without additional fuel, the Itasca would have to abandon the survey
within a couple of days or divert to Samoa for refueling. Meanwhile the
US Navy became seriously involved in assisting in the search, as the
Chief of Naval Operations authorized an aircraft carrier (the USS Lexington)
to get underway as soon as possible with destroyer escorts (eventually
USS Lamson, Drayton, and Hull). The Lexington
was in San Pedro (Los Angeles), and had to transit to San Diego to pick
up the aircraft. This was the fourth of July weekend, so getting airplanes
and crew from liberty on short notice was difficult. At 2312 GMT on July
3rd, the USS Colorado departed Hawaii to help in the search. The
Colorado carried three Vought OS2U “Corsair” two-seater scout
aircraft, capable of being catapulted from the deck and recovered in the
water from the battleship Colorado. The Colorado was on a
NROTC training cruise when it was diverted from liberty call in Hawaii.
All times GMT unless otherwise noted.
CG station in San Francisco asked the Itasca to stop transmitting
on 3105 and 6210 kHz, so a better verification of signals from Earhart
could be accomplished. Over the previous 10 hours or so, message traffic
regarding what the Achilles heard and how it correlated to
the Itasca broadcasts consumed a fair amount of energy and
time for various parties. The concern was that amateurs and other
radio stations might have been hearing signals really coming from
headed west to begin a survey 225 miles west of Howland, based upon
the LA radio amateur reports and another amateur report (later determined
to be unreliable), which at this time represented the only credible
clue as to where Earhart might be located. The intent of the Itasca
was to transit during the night to 179o W to begin a north-south survey,
progressing eastward towards Howland Island.
|| The PBY plane
arrived back safely in Pearl Harbor. The Colorado worked the
flight as plane guard just south of Hawaii, because the plane was
seriously short of fuel. This delayed the Colorado slightly
on her way south.
Airways (PAA) station in Wake heard signals on 6210 kHz, but was told
to change to 3105 kHz, as there appeared to be more activity on that
frequency. Nighttime was approaching, and radio signals were beginning
to be heard, as the propagation characteristics dramatically improve
|| The CG station
in San Francisco confirmed the LA amateur radio operators’ report
of 179o, 1.6, being SW of Howland. Since there was no west, east,
north, or south provided, this was not much of a clue for Itasca,
but at least the Itasca’s superior commander was reinforcing
Thompson’s decision to search that area.
station of 2.5 kW at 750 kHz) broadcast to Earhart and PAA Honolulu
heard returning signals on 3105 kHz.
station of 1.0 kW at 1320 kHz) broadcast a series of messages to
Earhart, and a large number of responses were heard by various parties.
Both radio stations were easily heard throughout the central Pacific,
provided the radio was tuned to those frequencies. The idea was
that if Earhart could receive any radio signals at all, these two
strongest signals should be able to reach her. There is not a lot
of first hand documentation of the broadcasts, nor of the responses.
Relying primarily on newspaper accounts, a map with annotations
kept by the Navy at the 14th Naval District (now in the Archives
collection in San Bruno), and various message traffic, here is what
we think happened. KGU may well have prompted Earhart to pay attention
to the KGMB broadcasts to start at 1000 GMT, as KGU, being more
powerful, was required by law to shut down later that night. It
would be better to rely upon KGMB for information, as it had a license
to operate continuously. The KGMB broadcast asked Earhart to respond
with 2 dashes if on water, and 3 if on land. Army station Ft. Shafter
in Hawaii indicate three distinct dashes between 0850 and 0900 GMT
(i.e. Earhart was on land). The map has these annotations:
of 3rd –
The Honolulu Advertiser
indicates a response of four dashes, possibly indicating a position
north of Howland, but what time nor in response to what specific broadcast
is not mentioned. Other correspondence indicates four dashes were
received as well. While not crystal clear, at least someone was responding.
More on this will be discussed later, when the broadcasts were repeated
the following night. Meanwhile, from 1000 to 1137 GMT, the Itasca,
PAA Honolulu and PAA Wake all heard carriers and signals on 3105 kHz
and 6210 kHz, but none of the signals were readable.
KGMB Requested a Broadcast –
0630 GCT 4th (8 PM Local Honolulu Time to 2:15AM)
Asked for 8 dashes if on water – got eight in response.
Asked for 4 dashes if north of Howland and 6 is [sic] south
[covered by ink stain] received
|| The CG station
in San Francisco reported hearing 6210 kHz from the west. This is
not surprising, as all of the radio operators generally knew where
Earhart went down relative to their own locations, and are most likely
to search in the direction of that quadrant.
||PAA Wake heard
a wobbly voice on 3105 kHz, described as being a man's voice.
||PAA Midway reported
that PAA Honolulu obtained a bearing of 175° on these signals.
At 1523 GMT, PAA Honolulu reported a bearing of 213° ±
(another document states 210°), and reported that to the CG station
in Honolulu. At 1540 GMT, PAA Wake obtained a bearing of 75°.
Finally, some real progress! Unfortunately, radio bearing direction
finding, to be accurate, must have at least two stations making measurements
on the same signal at the same time to provide a reliable location.
Obviously, the Wake measurement cannot be from Earhart. More on accuracy
of radio bearings later on.
|| The Lexington
left San Pedro for Coronado Roads (off San Diego).
Itasca started its box search west of Howland.
|| The CG Hawaii
radio station began to set up the schedule for the KGMB broadcast
later that night, and requested the Itasca not to broadcast
on 3105 or 6210 kHz to better determine the origin of the signals.
Apparently, the radio bearings obtained so far possibly indicated
that it was the Itasca everyone was homing in on.
Lexington group with the destroyers left San Diego, bound for
Hawaii for refueling prior to moving south to Howland to conduct the
asked the CG Hawaii station permission to broadcast on 3105, 6210,
and 7500 kHz between 0730 and 0830 GMT July 5, as it was in the best
position for Earhart to possibly receive radio signals.
|| The CG relents
and allows Itasca’s to transmit on these frequencies.
Colorado began to send messages to the Itasca regarding
refueling details at sea. It appears that the Itasca was not
equipped with the proper gear for at-sea fueling, and some adjustments
needed to be made to be able to do so.
broadcast on 3105 kHz, and PAA Honolulu obtained a bearing on the
Itasca of 210°. Based upon the position of the Itasca,
the true angle at Honolulu should be 229.2°, a discrepancy of
its second night of broadcasts to Earhart. The instructions were
for Earhart to turn on her transmitter for one minute for tuning
purposes, and then to send four long dashes if she heard KGMB, then
to wait for an acknowledgement by KGMB fifteen minutes later. PAA
Honolulu (Makapuu Point), heard four dashes, and asked KGMB to repeat
the message. Evidently, KGMB did so, as PAA reported hearing only
two dashes as if power failed on the transmitter. At 0700, 0715,
and 0730 GMT, Navy Radio Tutuila, American Samoa, heard four, four,
and eight dashes respectively. The Honolulu Advertiser reports:
Earhart was asked to use the carrier break four times if she was
north of Howland, six, if south. She was asked to break twice to
indicate if she were on land and three times if she were on water.
What we don’t
know is if Earhart was to add these numbers together (six to nine
total dashes possible) or at fifteen minute intervals. If the former,
Radio Station Tutuila indicates eight dashes, or south, and on land.
Meanwhile, PAA Honolulu obtained bearings of 213 and 215° on the
0630 GMT responses, depending upon the source. Itasca did not
hear a single dash in response to KGMB. Midway picked up a bearing
of 201°, but on a frequency halfway between Itasca and
Colorado, slightly above 3105 kHz. Radio Tutuila heard nothing
suspect that KGMB asked Earhart to respond with four dashes if north
of Howland, six if south, and Tutuila heard four dashes. CG Radio
Hawaii reported that PAA Honolulu reported a bearing of 200°T[rue],
but we don't know at what time that bearing was obtained.
||We suspect KGMB
asked for two dashes if on land, and three if on water. Tutuila heard
eight dashes, four of which were strong, and possibly voice on 3105
the next few hours, a large number of reported signals were heard
by Itasca, Baker and Howland Islands, and the PAA radio stations.
Some of the most interesting:
hears a generator start and stop on 3105 kHz.
Both Baker and Howland Island report hearing a voice on 3105 kHz.
Howland Island reports hearing Earhart.
PAA Midway obtains a bearing of 175°, considered coming from South
America or Russia, so it was disregarded.
After being chastised by Itasca, Howland restarts its Earhart
radio watch and obtains a bearing of NNW/SSE on magnetic pocket compass.
States that it cannot determine which direction due to “night effect.”
Interestingly, despite access to a theodolite for weather balloon
measurements, no azimuthal calibration was made on the Howland direction
finder. A pocket compass was the only available device. Night effect
is actually a swinging of the directional bearing due to night propagation
effects, and what Cipriani really means is that there is no way of
determining a unilateral direction without a sensing radio to add
to the direction finder.
Station Wailupe began to hear a ragged keyed message on 3105 kHz,
which is reported to state: “281 North Howland Call KHAQQ beyond North
don’t hold with us much longer above water shut off,” received
by three Navy operators. Of all the post-loss radio messages, this
particular message has the best chance of being from Earhart, particularly
if it is proved that she landed at Gardner. It turns out that Gardner
is 281 nm south of the Equator, and that distance can be easily determined
by any experienced navigator. Since the message was ragged, perhaps
the message was really “equator is 281 north of us.”
PAA Wake reported a bearing of 144°, strength 5. This is likely
the Itasca, who was broadcasting at the time and was bearing
141.56° true at Wake. Simultaneously, Midway obtained a bearing
of 201°, well away from the possible location of Earhart, but
possibly from the Itasca.
diverted course for a position 281 nm north of Howland, believing
the latest radio report. Itasca directed Swan to also
move to that location to help conduct a search. A few hours later,
the SS Moorsby, en route to New Zealand, offered assistance
to the Itasca, and was directed to also go to a line 281 nm
north of Howland.
Howland heard Japanese music on 3105 kHz, which it continued to do
until the 17th of July. So far, we have not been able to identify
what station was broadcasting on 3105 kHz.
heard Russian stations on 3105 kHz. We know of two low wattage stations
from Siberia that might fit this description.
Verification from Lae was received that Earhart left with 1100 gallons
of gasoline, with an estimated 24 to 30 hour duration in the air.
|| The CG station
in San Francisco reported that radio technicians familiar with the
plane said that the radio is unable to function on water, so therefore
if the signals are to be believed, she must be on land. They also
state that they believe Earhart flew the line of position to the Phoenix
Islands. This radio message is the first to indicate that searching
at sea might well be useless if one were to believe the various radio
during July 5th, a State Department memorandum from the Division of
Far Eastern Affairs documents a phone conversation with Tsuneo Hayama,
the Second Secretary in the Japanese Embassy, describing a telegram
received from Tokyo offering assistance of the Japanese government,
warships, and radio stations in the Marshalls. The US responded with
current US ship assets and for Japanese authorities to coordinate
with the Commandant 14th Naval District. The only Japanese ship that
we are aware of that actually searched for Earhart was the Koshu,
a oceanographic survey vessel, which departed its survey at 2200 GMT
for the Marshall Islands, arriving sometime about the 9th.
||The CG Station
in San Francisco relayed an opinion from PAA authorities that the
281 message may well be referring to the Phoenix Islands, as the radio
bearings were beginning to intersect in that area.
||A report from
the CG station in San Francisco documented that Lockheed Aircraft
had definitively stated that the radio was inoperable if the plane
was in the water.
asked Howland to take a bearing on it at 0800 GMT. At 0832 GMT, Howland
reported that the bearing was NNW or SSE, taken with a magnetic pocket
compass. The Itasca at this time was 342.2° relative to
Howland (magnetic), a good match to the 337 degrees reported. At 0930
GMT, Howland took another bearing, observing NW (315 degrees), versus
the 345.9 magnetic orientation to Itasca, a far worse bearing
error of nearly 31 degrees. At 0947 GMT, PAA Honolulu reported a bearing
on the Itasca of 196.5°, but the bearing to the Itasca
is really 232.38°, an error of nearly 36°! Based upon these errors
obtained over the past couple of days, direction bearings should be
considered indicators of direction, and not treated as literal bearings
with any accuracy.
and Swan saw heat lightning, which they interpret to be flares, and
broadcast in the clear to Earhart: “we see your flares and are rushing
to your location.” Unfortunately, a wide variety of people were listening
in and a mad rush of press reporters sent out radio messages to the
Itasca asking for information, pictures, etc. A few minutes
later, the Itasca recognized that these were not flares, and
with the latest information that Earhart is probably on land, abandoned
the 281 North Howland line search and headed south at 1554 GMT to
rendezvous with the Colorado for refueling at 1730 GMT on July
Chief, US Navy ordered COM14 to take charge of the search, as the
battleship Colorado was about to enter the search area, and
the Lexington group would be arriving shortly.
|| CG Headquarters
approved the Itasca to be placed under control of the US Navy,
and at 0053 GMT July 7th, the Itasca reported to COM14 for
duty, ending its independent search for Earhart.