# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Finding Howland Island
From: Gary LaPook
Date: 2010 Feb 06, 01:53 -0800

```I'm not sure what eight degree difference you are talking about.

Clarence Williams was hired by Earhart to do some of the planning for
the world flight. Since the original plan was to travel westward he
calculated the leg from Howland to Lae with an initial great circle
course of 257.3° True. He then applied the variation of 9° East
resulting in a Magnetic Course of 248.3°. When they reversed the route
they simply subtracted 180° from the prior computations making the
inbound course to Howland 68.3°° M, 77.3 T.  My calculations came up
with 77.6° T, rounded to 78° T essentially the same result as Williams.
The distance is 2222.6 NM, 2556.0  SM, the same as Williams' calculated
distance. See attached Williams' documents.

He used 6° 47' S, 147° 00' E for the location of Lae and 0° 49' N, 176°
43' W for Howland. The coordinates for Lae, based on the official 1935
Australian chart (New Guinea was administered by Australia at the time)
are 6° 48' S, 147° 02' E an insignificant difference from the
coordinates used by Williams. See attached chart.

Williams used 0° 49' N, 176° 43' W for Howland, about 5 nm west of the
actual location given in the 1938 Bowditch as 0° 48' N, 176° 38' W. This
is what gave rise to the theory that Noonan was aiming for the wrong
coordinates, causing him to miss the island. But Williams did his
calculations early and the correct location of Howland was determined by
the Itasca after Williams had completed his work but well before Earhart
departed on the second, eastbound, attempt so these correct coordinates
may have been available to Noonan for his approach to Howland. Either
way, the error was not great enough to cause them to miss the island.

I have checked Williams' work and the points that I calculated for the
great circle are within two nautical miles of the ones listed by him. My
calculations show that the initial GC course from Lae was 79.5° T and
the final course was 77.6°  T, a change of less than two degrees. The
numbers shown on Williams chart show a greater change of five degrees
but his are magnetic courses and the variation changed by about three
degrees from Lae to Howland accounting for this difference, see the
charts at:

http://www.fer3.com/arc/m2.aspx?i=110847&y=200911

I have attached a place mark file to take you to Howland on Google Earth.

The rhumb line course from Lae to Howland is 78.2°  T and the rhumb line
distance is 2222.7 NM, only one-tenth of a mile longer than the great
circle since the route was along the equator.

gl

Ted Campbell wrote:
>
> On William's Nav guide for this flight he had a course of 68 degrees
> from Lae to Howland. How would this 8 degree difference effect your
> analysis if AE and FN followed this line?
>
> Ted Campbell
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```

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