NavList:

I agree. The most obvious answer is:

1. The plan was to approach Howland at night (for celestial nav purposes) and
land at dawn.
2. Headwinds delayed the plane. NOAA/ERSL's 20th century reanalysis for that day
puts zonal winds at 13 to 14 knots over most of the route. Thus the sun rose
hours before Howland was reached, eliminating most close-in celestial nav -- and
eating up the fuel reserve too.
3. After sunrise, it would make sense that Noonan took sunlines. This would
allow them to know if they had flown far enough to reach Howland, but not
whether they were north or south of the island.
4. Earhart's last message was that they were on a 157-337 line flying north and
south. Clearly a sunline, since it is at right angles to the solar azimuth. So
Noonan's sunline had finally reached Howland, but the island was not visible.
They were flying along this line (probably in the wrong direction) searching for
Howland when their fuel ran out shortly afterward.
5. They were less than 50 miles from Howland (good radio reception implies
line-of-sight at 1000 feet) but farther than 6 miles (or they would have been
heard audibly). If you want to look for wreckage on the ocean floor, that's
where to look.

Keith Pickering

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