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    Re: Longhand Sight Reduction
    From: UNK
    Date: 2014 Nov 14, 07:33 -0000


    The “Chichester test” is just a bit of a joke from me. It relates to Francis Chichester’s famous (or infamous?) solo flight across the Tasman sea in April 1931. He navigated by frequent sextant sun sights and worked out his LOPs with the Bygrave slide rule, saying that he made too many mistakes with logs etc for longhand method.(There were no short reduction tables in those days.)  He had to do all this with one hand while flying the unstable biplane (Gary has flown similar and knows!) at 200ft altitude etc. He managed to find the tiny Lord Howe Island after several hours and hundreds of miles. If his navigation had been even a few miles out, he would have perished for sure.

    Therefore, for my fast, emergency LOP method evaluation, I use the “Chichester test”. Could he have used it for that mad trip?

    So far only the Bygrave and my MiniFuller cos slide rules have passed it. (obviously, an electronic calculator would pass, but that would be cheating in 1931!). He may have managed the Hanno/Greg Doniol Hv method, although he ,like me, said he makes mistakes with interpolation of 4 figure tables.

    So far , for me anyway, the Bygrave is king, but I think the latest Doniol is the best longhand method and makes short reduction tables obsolete..

    Hope that makes sense.

    Bye the way, last year Gary and then  I “re-enacted” the Chichester flight navigation using copies of the original charts and used our homemade Bygraves to work out the LOPs. We both got identical results to those published by Chichester. It was an amazing feeling to do that!



    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Rommel John Miller
    Sent: 14 November 2014 01:46
    To: francisupchurch---.com
    Subject: [NavList] Re: Longhand Sight Reduction


    What is the "Chicester test" as it pertains to navigation?  Is it anything like the test the County of Chicester in England gives in order to get a clean bill of helath in order to drive legally there? 

    is our CT named for the great Sir Francis, or simply a reference to this driving test in an English county? 

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