NavList:

From: Gary LaPook <garylapook@pacbell.net>
Subject: [NavList] Re: NP303 VOL2 covers 0-49 degree declination? vs. PUB/HO 249 VOL2 0-29 deg dec?
To: NavList@fer3.com
Date: Wednesday, November 14, 2012, 8:49 PM

You had me stumped. I read and re-read the example on my website and didn't see the error that you pointed out. The declination is 20 N in the example there: "The Bygrave doesn't require that the latitude or the LHA to be whole degrees so you can compute altitude (Hc) for your Dead Reckoned position but for convenience in this example we will use whole degrees, 34º North for latitude, 20º North for declination and a Local Hour Angle (LHA) of 346º." https://sites.google.com/site/fredienoonan/other-flight-navigation-information/modern-bygrave-slide-rule I then looked at the PDF copy available on the website and there the error is so you must be looking at that copy. Thanks for finding that typo for me, I will fix it. gl --- On Wed, 11/14/12, hanno ix <hannoix@att.net> wrote: From: hanno ix <hannoix@att.net> Subject: [NavList] Re: NP303 VOL2 covers 0-49 degree declination? vs. PUB/HO 249 VOL2 0-29 deg dec? To: "NavList@fer3.com" <NavList@fer3.com> Date: Wednesday, November 14, 2012, 7:20 PM Gary: It appears to me there is a little inconsistency within your Self-contained etc. which threw me off somewhat. In the 4th paragraph of the chapter "Modern Bygrave Slide Rule" you give an example with D=14deg N. However, you treat that example with D=20deg N. The result is consistent  with this value. Perhaps this has been noticed before. H From: Gary LaPook <garylapook@pacbell.net> To: NavList@fer3.com Sent: Sunday, August 12, 2012 10:22 AM Subject: [NavList] Re: NP303 VOL2 covers 0-49 degree declination? vs. PUB/HO 249 VOL2 0-29 deg dec? I always bring this up when people ask about selecting a sight reduction method. Try the Flat Bygrave slide rule that you can make yourself for about one buck that computes the data to the same level of accuracy as H.O. 249 and does the computation in less than two minutes, less than one minute when you get proficient. Go to my website at: https://sites.google.com/site/fredienoonan/other-flight-navigation-information/modern-bygrave-slide-rule To get compleet instructions on how to make and use one of these. Also look at: https://sites.google.com/site/fredienoonan/other-flight-navigation-information/self-contained-long-term-celestial-navigation-system for a complete system which takes only five sheets of paper plus the two plastic sheets that comprise the Flat Bygrave itself. gl