NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Landfall procedure
From: Gary LaPook
Date: 2015 Jan 30, 23:21 -0800
From: Samuel L <NoReply_SamuelL@fer3.com>
To: garylapook@pacbell.net
Sent: Friday, January 30, 2015 1:26 PM
Subject: [NavList] Landfall procedure
From: Gary LaPook
Date: 2015 Jan 30, 23:21 -0800
There is a way to work the computation from a DR position using HO 249 or HO 229. Those tables only have a correction for "delta d", the difference in the declination from whole degrees. HO 214 also had corrections for "delta t" the difference of LHA from whole degrees and a table for a correction for "delta L" the difference in latitude from whole degrees. I posted how to do this before so see the links below. Since Noonan did not have HO 214 he used HO 208 which also requires an AP making whole degrees of latitude and of LHA. The way this is handled is graphically and I will expand on that in a subsequent post.
gl
From: Samuel L <NoReply_SamuelL@fer3.com>
To: garylapook@pacbell.net
Sent: Friday, January 30, 2015 1:26 PM
Subject: [NavList] Landfall procedure
Gary,
I've read the Landfall procedure you used in your flight to Catalina island. Also, I read the AFM Landfall procedure portions you have on your website.
In general it seems pretty simple but I have a question for you which probably applies to how Noonan would have used the Landfall procedure to find Howland.
How did you determine the Hc of the shots based on your destination's location considering HO 249 is based on whole degree of
Latitude and LHA?
You can obtain such accuracy using a calculator but not with HO 249.
I think we'd all enjoy hearing more your flight stories.
Thanks,
Sam Lohengrin
