NavList:

   

Reply

Hewitt,

Go to page 42 of volumn #1 Bowditch 1977 edition and you will find the
description of Sumner's accidental discovery of the celestial line of
position while off the lee shore of Ireland entering St. George's
channel. On page 55 of the 1958 edition of Bowditch there is a chart
with Sumners original line of position plotted. Dutton's 1969 edition
briefly describes Sumner's line of position discovery on page 7.

Greg

On Aug 2, 10:08�am, Hewitt Schlereth  wrote:
> Then there's Captain Sumner's landfall by single LOP in 1837. The
> extract from his log is terse and tense - maybe 400 words. Gripping.
> Used to be in older editions of Bowditch. I don't find it though in my
> 1977. �-Hewitt
>
> On 8/2/09, glap...@pacbell.net  wrote:
>
>
>
> > �also see:
>
> > �http://www.geocities.com/fredienoonan/chichester.html
>
> > �gl
>
> > �On Aug 2, 5:57 pm, "glap...@pacbell.net"  wrote:
> > �> Here are links to prior posts on Chichester's navigational procedures:
>
> > �>http://fer3.com/arc/m2.aspx?i=108625
>
> > �>http://fer3.com/arc/m2.aspx?i=108623
>
> > �> gl
>
> > �> On Aug 2, 5:35 pm, "glap...@pacbell.net"  wrote:
>
> > �> > "It was a fourteenth the size of the smallest compulsory landfall made
> > �> > by an
> > �> > aeroplane. From New Zealand it presented a target half a degree in
> > �> > width. And my
> > �> > compass, recently swung twice on that bearing, had varied 9 degrees
> > �> > during the
> > �> > interval; further, it was nothing to drift 30 degrees in a stiff wind.
> > �> > And since
> > �> > an error in the course of only 5 degrees meant passing the island 50
> > �> > miles away,
> > �> > it was plain I could only depend on the sun to find it.
>
> > �> > "Instead of heading direct for the island, I altered course 10 degrees
> > �> > for a
> > �> > point 90 miles to the left of it. Flying towards this imaginary point,
> > �> > I must
> > �> > observe the sun carefully until it gave me the exact bearing of
> > �> > Norfolk Island
> > �> > on my right, and showed me to be on the line through point and island.
> > �> > I must
> > �> > then immediately turn to the right and head direct for the island.
>
> > �> > "I must make no mistake and turn neither a minute too soon nor a
> > �> > minute too
> > �> > late."
>
> > �> > Seaplane Solo, Francis C. Chichester, 1934.
>
> > �> > The offset had nothing to do with a possible error in the sextant
> > �> > reading which
> > �> > he needed to be accurate enough to put him on the LOP through Norfolk
> > �> > close
> > �> > enough to spot the island. The offset related to the possible error in
> > �> > the DR
> > �> > after traveling almost 600 miles.
>
> > �> > The book is great, very exiting and well written
>
> > �> > Also see the topic Single LOP landfall procedure at my 
website:http://www.geocities.com/fredienoonan/
>
> > �> > gl
>
> > �> > On Aug 1, 6:26 pm, Tom Sult  wrote:
>
> > �> > > Gary....
> > �> > > Sounds like a great day at the Aerodrome! �I also am a pilot, and
> > �> > > would love a copy of the book. �If you can email it to ts...@mac.com
> > �> > > Thanks.
> > �> > > Thomas A. Sult, MD
> > �> > > IntegraCare Clinicwww.icareclinics.com
> > �> > > ts...@charter.net
>
> > �> > > On Jul 31, 2009, at 8:59 PM, Gary LaPook wrote:
>
> > �> > > > My interest in the Bygrave was triggered by my reading Sir Francis
> > �> > > > Chichester's account of flying a Moth, open cockpit single engine
> > �> > > > airplane across the Tasman Sea in 1931 doing celnav on the way to find
> > �> > > > two tiny islands where he could refuel, each leg about 500 nautical
> > �> > > > miles. Today, at Headcorn Aerodrome in England, I had the
> > �> > > > opportunity to
> > �> > > > fly the same type of aircraft and my admiration for Chichester
> > �> > > > increased
> > �> > > > ten fold. It is a very light aircraft so it is bounced around a lot my
> > �> > > > even the lightest turbulence. The controls are very sensitive,
> > �> > > > especially in pitch, so it takes a lot of concentration to keep the
> > �> > > > plane flying straight and level. It is also very noisy and the wind
> > �> > > > blows vigorously through the cockpit. I don't know how Chichester
> > �> > > > managed to do it, flying the plane, shooting sun lines with �a marine
> > �> > > > sextant, doing the computations with the Bygrave (holding it
> > �> > > > horizontally so it didn't get blown out of the cockpit), estimating
> > �> > > > drift angle, and plotting the LOPs and the drift lines. I recommend
> > �> > > > this
> > �> > > > book, Seaplane Solo, to everybody and I can email a copy to anyone who
> > �> > > > is interested.
>
> > �> > > > gl
--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---

   

Reply