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Re: Flight 19 route: wrong course
From: Gary LaPook
Date: 2009 Nov 25, 18:56 -0800
From: Gary LaPook
Date: 2009 Nov 25, 18:56 -0800
As I said in September: http://www.fer3.com/arc/m2.aspx?i=109853&y=200909 "I went to plot these courses on my Miami Sectional and found that I had already plotted the courses of Flight 19 several years ago, but I noticed a difference. The first course I had plotted is 097�T not the 091�T in your post. I don't remember where I got the course that I had plotted years ago. But, with the legs I had plotted in the past the three legs do take you back to Ft. Lauderdale. The end of the second leg is right over Great Stirrup Cay. But there is yet another mystery. The planes were supposed to have practiced bombing on a ship wreck. That wreck is the ship Sapono. The problem is that the Sapona is 25.6 NM SSW of Great Issacs, I know because I have dived upon it. Its location is 25� 30.1' N, 79� 17.6' W'. I am attaching a photo from Google Earth of the ship. Here is a link to more information about the ship. So is there a different ship that they were to bomb? If not then why didn't the nav problem give an accurate course to the Sapona? If they took their departure from the Sapona for the second leg then the successive courses would take them back quite a bit south of Ft. Lauderdale. Any ideas?" I had also plotted 091� T for the first leg and the second leg also ended up at Great Stirrup Cay. Where does the location of the Sapona fit into your picture? gl gl Paul Hirose wrote: > Flight 19 (of "Bermuda Triangle" fame) was supposed to fly true course > 091 to begin their navigation exercise, according to many Web sites. In > fact, I've never seen anything to the contrary. > > http://www.history.navy.mil/faqs/faq15-1.htm > http://www.ibiblio.org/hyperwar/USN/rep/Flight19/ > > However, there's some evidence that the true courses widely quoted on > the Web are wrong. See the image of a chart (said to be from the > official report) on this Web page: > > http://www.bermuda-triangle.org/html/bad_navigation_.html > > Obviously, the first two legs cannot be true course 091. The angle of > the blue line with respect to the nearby parallel of latitude is much > greater than one degree. > > By opening that image in an application such as Windows Paint it's > possible to read pixel coordinates of any point in the image. Then with > plane trigonometry you can determine the orientation of the course > lines and meridians. With respect to "image north", I calculate that the > meridians are oriented to 357�, and the three sides of the route are > 94�, 345�, and 238�. Therefore, with respect to the meridians, the true > courses are 097, 348, and 241. Compare those figures to the conventional > values widely given on the Web: 091, 346, and 241. > > In an earlier posting I noted that the conventional courses and > distances, when plotted, fail to close on the start point. The > discrepancy is 10.6 NM, or 3.4% of the total distance. But if the > courses I measured on the picture are used instead, this is reduced to > 2.2 NM, or .7% of the distance. That's excellent when you consider that > all courses and distances were rounded to 1 degree and 1 mile. (The plot > was actually done mathematically on a Mercator grid to simulate an > aircraft flying rhumb lines.) > > The Web page with the chart has something else which tends to confirm my > theory. It says the planned route went to Great Stirrup Cay. Well, > with course 091 you'd miss the cay by 32 NM. But course 097 takes you > within a mile at closest approach, and at my calculated turn point > you're just 3 miles away. > > Flying my courses (but using the conventional distances), the endpoints > of the legs are: > > N26�03.0' W080�07.0' start; depart on TC 097 > N25�56.2' W079�05.3' Hen and Chickens Shoals; depart on TC 097 > N25�48.0' W077�51.5' turn to TC 348 > N26�59.6' W078�08.4 turn to TC 241 > N26�01.2' W080�09.2' end > > The point I labeled "Hen and Chickens Shoals" is 4 NM from the wreck of > the concrete ship Sapona, which was probably a target for Flight 19's > bombing practice. (This route goes right through the present day airway > intersection BAHMA, depicted on the Miami Sectional Aeronautical Chart.) > > > All these computations are based on one small image on a Web site, so > I'm not going to claim there's something wrong with the widely quoted > courses. It's hard to believe that such a discrepancy could have escaped > detection. But it's interesting that when the new courses are plotted, > the former misclosure in the route practically disappears. > > Finally, none of this gets us any closer to the reason for Flight 19's > disappearance. It's strictly about two possible garbles in the > description of the navigation problem, as it has been passed down to us. > > -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com