NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Flight 19 route
From: Paul Hirose
Date: 2009 Sep 20, 11:14 -0700
From: Paul Hirose
Date: 2009 Sep 20, 11:14 -0700
I wrote: > Except for the first (which comes from the Navy report), I calculated > those points on both a Mercator grid and a Lambert conformal conic grid, > the latter with standard parallels N25°20' and N30°40'. Those are the standard parallels of the modern Miami sectional aeronautical chart. It can hold the entire route, though the north point of the triangle is on the opposite side of the chart from the other two. A similar chart may have been used to plot the navigational problem back in 1945. By then the Coast and Geodetic Survey had decided on the Lambert conformal conic projection for aeronautical charts, and the whole country was covered by 1:500,000 charts in a scheme similar to today's. Modern sectionals use the same scale, but are larger. For example, in the 1939 edition of "Practical Air Navigation", published by the C&GS, the diagram of sectional charts shows the Miami one does not extend as far east as the present day chart. You couldn't have plotted the Flight 19 route on it. > If they had started the second nav leg from SS Sapona instead of the > island, that would have offset the rest of the flight a few miles to the > south, and put the end point closer to the airfield. This may very well > have been the intent of the exercise. That route would end at N26°10.5' W080°10.6', 8.2 NM from the departure point. It's not much improvement. -- --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---