The radio operator
at Lae, Harry Balfour, made no written record of what he heard from
the Earhart flight and the recollections he wrote down in 1969 disagree
with the Chater and Collopy documents, written in July, 1937. Not
only do Chater and Collopy both contradict Balfour, they disagree
with each other about the content of the messages received from
Earhart.
Both Chater
and Collopy agree that the aircraft departed Lae, New Guinea at
0000 GMT, or 10AM local time.
Chater states
that local interference prevented signals from the plane to be heard
at Lae until 0418 GMT, but that a call had been made to the plane
at 18 minutes past each hour to pass weather information.
Chater states
that at 0418 GMT, the Lae radio operator heard on 6210 kHz: “Height
7000 feet, speed 140 knots” then some remark concerning “Lae” then
“everything OK.” Chater further states that the plane was called
and asked to repeat its position but got no response. Collopy makes
no mention of this message. At 4 hours and 18 minutes into the flight,
the 7000 foot altitude makes sense, but the reported speed of 140
knots seems odd. At that altitude, and in a still heavily-overloaded
airplane, we might expect Earhart’s airspeed indicator (which read
in mph, not knots) to show a figure slightly less than her normal
cruising speed of 150 mph (130 knots). So, if she had simply said
“speed 140” the report would make sense. On the other hand,
if the expression was truly in knots, then it must have been calculated
by navigational landmarks or sun-lines by Noonan, and indicates
true speed over the ground. If this was the case, then the airplane
would have a 10 knot tailwind, or be operating at an uneconomical
power setting. It would seem more reasonable to attribute the discrepancy
to a knots vs. mph misunderstanding at Lae.
At 0519 GMT,
Earhart again broadcast a message on 6210 kHz. Chater reports: “Height
10000 feet position 150.7 E 7.3 S cumulus clouds everything OK.”
Collopy states: “At about 3 PM local time a message came through
to the effect that they were at 10,000 feet but were going to reduce
altitude because of thick banks of cumulus clouds.” This is a puzzling
message. The coordinates related by Chater place the airplane well
south of the intended rout and, although the flight had been en
route for 5 hours and 19 minutes, the position reported is only
186 nm from Lae, giving the airplane a ridiculous ground speed of
37 knots. The reported 10,000 feet of altitude is higher than the
8,000 feet recommended by Kelly Johnson for best fuel economy on
this portion of the flight. None of this message makes sense in
the light of the reported comment “everything OK,” and we must
conclude that either the message or its transcription was inaccurate.
At 0718 GMT,
the last and final message was received by Lae personnel from Earhart.
Chater reports: “Position 4.33 S 159.7E height 8000 feet over cumulus
clouds wind 23 knots.” Collopy states: “The next and last message
was to the effect that they were at 7,000 feet and making 150 knots,
this message was received at approx. 5 PM local time.” Again,
there are discrepancies between the two reports. The position provided
places the plane in the vicinity of the Nukumanu Islands (4.3°S,
159.30°E). No time was provided for when this position was
obtained. This position is 735 nm from Lae and is right on course
for the great circle route to Howland, and seems suspiciously
to be a dead reckoning position. First, there were no good maps
of the Nukumanu Islands at small scales in 1937; secondly, Noonan
had a habit of marking half-hourly projections along the intended
flight path and was known to relay these positions to Earhart
(see discussion on the Oakland to Honolulu segment previously);
navigation during daylight hours was limited to lines of position
shot from the sun and any visual landmarks; and the double digit
accuracy of the latitude position seems unusual but it may simply
indicate 1/3 of a degree. The reported altitude of the plane (8000
feet) is consistent with fuel economy plans, but Collopy’s 7000
foot altitude and speed makes more sense if he was referring to
the message received 3 hours earlier. The wind speed of 23 knots
seems consistent with the Nauru observation of 24 mph (19 knots)
at 7500 feet, but Earhart did not give an indication of wind direction.
Finally, we note that the plane is above the clouds just as dusk
is approaching, allowing Noonan to obtain celestial fixes.
At this time,
according to Chater, Earhart changed radio frequencies from 6210
kHz, her daytime frequency, to 3105 kHz, the nominal nighttime frequency.
Chater reports that the signals up to this time were strong, and
the plane was called not to change frequencies. No replies were
heard or other messages during the next three hours as both frequencies
were scanned by Balfour. Chater's report clearly documents that
at no time did Earhart and Lae establish two-way communication,
nor is there any evidence that Earhart heard any of Lae's broadcasts
to her.
Meanwhile,
the Itasca radiomen had been running a radio watch on 6210,
3105, and 500 kHz, listening for Earhart since 1131 GMT, July 1.
At that time, the Itasca did not know when Earhart was to
take off, so they kept a continuous watch from that time forward.
At 0415 GMT on July 2, Itasca communicated with Radio Tutuila,
who stated that Radio Tutuila still had not heard anything via Suva
as to whether Earhart had left Lae.10
At 0542 GMT, Itasca intercepted a radio communication from
Radio Tutuila to Ontario saying that Radio Suva reports that
Earhart took off at 9:30 AM.11 At 0601 GMT,
Itasca received a telegram from the USCG office in San Francisco,
stating that Earhart left Lae at noon, Lae time. At 0630, the second
radio watch specifically for Earhart was established and began to
send weather reports on 7500 kHz; these transcripts are hereafter
referred to as Itasca2 radio transcripts, if smoothed, and
Bellarts for the original raw transcripts.12
At 0725 GMT, Itasca got a radio message from Vacuum Oil in
Lae that Earhart took off at 10AM local time, and her expected flying
time was 18 hours.13 At 0726 GMT, Itasca
reports hearing a faint signal on 3105 kHz from Earhart, strength
1, voice signal, but unreadable.14 This
was probably not Earhart, as it is not at her scheduled broadcast
time.
There
is little information regarding weather conditions during this first
segment of Earhart’s flight. The forecast from the Fleet Air Base
in Honolulu estimated that the winds around Lae were 25 knots ESE
from Lae to where the Ontario was situated (approx. 3°S, 165.6°E).
15 Nauru, located at 32′S, 166°55′E,
had reported at 2130 GMT on July 1 that it was experiencing 14 mph
(12.1 knots) winds from the East at 2000 feet, 12 mph (10.4 knots)
from the East at 4000 feet, and 24 mph (20.9 knots) from the East
at 7500 feet.16 The Ontario during
this time experienced Force 3 winds (7-10 knots) from 0000 to 0200
GMT, from NExE (56.25°), shifting to Easterly at 0200 GMT. At
0300 GMT, Ontario experienced easterly winds at force 2 (4-6
knots), then from 0400 to 0900 GMT, experienced easterly winds
at force 3.17 Generally below the
meteorological equator, located at this time of the year at 5°N,
winds shift northerly with altitude from the sea by about 10 degrees
to the north, and experience a 30% increase in speed. |