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Subject: Celestial Navigators
From: John LeRoy (jleroy@XXX.XXX)
Date: Thu May 23 2002 - 00:25:48 EDT
George,
Stephen Casner said;
>> I'm writing an article for an aviation magazine about ... celestial
>> navigation. Are there any pilots out there that used to do celestial in
>> airplanes? I'm looking for any experiences, histories, insights, and
>> quotes that might make interesting material for this piece.
While I did get qualified in celestial navigation using a bubble sextant in
a Navy P2V, I really never did use that skill in practice. I did all my
overwater navigating in a DC-10 and 747-400. (I used to habituate bluecoat.)
However, I think you would be interested in the fact that Sir Francis
Chichester was the first to fly from New Zealand to Australia. He used a
Gypsy Moth biplane as I recall, equipped with floats and landed next to Lord
Howe Island, the Royal Navy hoisted him on the island with a crane, refueled
him, put him back in the water and the was on his way. (I must admit that I
once deviated from the direct course from Aukland to Melbourne to take a
look at that island!)
His problem was to find Lord Howe. He solved this problem by calculating the
angle of the sun above the horizon on a North South line through Lord Howe
for 15 minute intervals over a period before and after his ETA. He then
took a heading far enough south of Lord Howe to insure that he would be
south of Lord Howe with the greatest south wind he felt he could expect.
At 15 minute intervals he would bank the biplane to the point that he could
take a sight (with a marine sextant) on the sun between the wings. As I
recall his arrival was in the afternoon, so the first sights he took found
the sun too low, so he kept heading west. As he neared the line, the sights
would approach the pre-calculated value for that 15 minute interval. When he
was on the line, the sight was the same as calculated for that time and he
turned right, flying up the line, when the sight was too low, he turned
left, too high he turned right, and flew right up the line to the island.
Sir Francis's later exploits were in circumnavigating the globe and other
long distance trips in a sailboat, named the Gypsy Moth II, III etc.
He wrote a book about his aerial adventure, I wish I could think of the
name, but you should be able to find it by the author's name.
Regards;
John LeRoy
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