i have some new thinking about the first section (Lae to nightfall) segment of the flight.
According to
Chater, "Arrangements had been made between the plane and Lae station to call at 18 minutes past each hour." Lae heard three reports from Earhart:
• Nothing was heard for the first three hours due to local interference.
• At 04:18Z, four hours and eighteen minutes after departure, Earhart reported "“HEIGHT 7000 FEET SPEED 140 KNOTS” and some remark concerning “LAE” then “EVERYTHING OKAY”.
• At 05:19Z she said, "HEIGHT 10000 FEET POSITION 150.7 east 7.3 south CUMULUS CLOUDS EVERYTHING OKAY”.
• Nothing was heard at 06:18Z.
• At 07:18, she said, "POSITION 4.33 SOUTH 159.7 EAST HEIGHT 8000 FEET OVER CUMULUS CLOUDS WIND 23 KNOTS”
The 04:18Z message contained no intelligible position information.
The position reported in the 05:19Z message, as recorded by Chater, cannot be correct.
The position reported in the 07:18Z message roughly corresponds with the Nukumanu Islands and is on track for Howland.
In the past, we have ignored the 04:18Z message as useless and dismissed the 05:19Z call as obviously incorrect, so we've assumed a straight line course from Lae to the 07:18Z position, as shown in the first map below.
It has been suggested by several researchers the longitude in the 05:19Z message was misheard or mis-transcribed. Instead of 150.7° E it should be 157° E. That sounds reasonable. The distance from lae is with the realm of possibility but it puts the airplane well south of course on the coast of Choiseul in the Solomons. Why would they be there?
According to Chater, the weather forecast from Fleet Air Base, Pearl Harbor warned of "dangerous local rain squalls about 300 miles East of Lae." If the forecast was correct, Earhart may have gone south to find better conditions. If so, the 04:18 message makes sense. She did not report her position because she didn't know precisely where she was, but she had a bit of a tailwind and the weather was good so everything was okay. An hour later, Noonan was able to get a precise location from landmarks on the Choiseul coast - but her report was erroneously recorded.
If that's what happened why did Noonan, in a departure from his usually loose en route navigation habits, then plot a big course correction to get them back on the original track to Howland? Probably because if he simply plotted a new direct route to Howland they would miss any chance to confirm their progress with USS Ontario whose position was based on the original planned route.
This all makes sense to me but it means the flight covered more miles in the same time than we previously assumed. The second map below shows the new hypothetical route with [urlhttps://tighar.org/Projects/Earhart/Archives/Documents/Collopy_Letter.html]Collopy's[/url] version of the messages added.
The weather diversion only adds about 130 nm to the trip, which amounts to one hour at the plane's 130 kt cruising speed. AE expected an 18-hour flight to Howland but it took 19 hours to get to "We must be on you.." Maybe this is why.