[Milsurplus] Interesting web site - P-38 radio

[D C *Mac* Macdonald]

I don't know how/when/where/why they call it "dead" reckoning. 
It is a contraction of "deductive reckoning" and should have been 
spelled "ded" reckoning. 
 
Mac, K2GKK 

Oklahoma City 
 
 
 
> From: smithab11 at comcast.net 
> To: milsurplus at mailman.qth.net 
> Subject: Re: [Milsurplus] Interesting web site - P-38 radio 
> Date: Sun, 2 Dec 2007 12:55:30 -0500 
> 
> My guess is that they installed an "Astro Compass" on the aircraft which 
> allowed them to obtain a true heading from the sun using precomputed sun 
> azimuth information for time and location along their track. This would 
> eliminate all "charted magnetic variation errors" and aircraft compass 
> system errors as they would be dealing strictly with "true heading". 
> Possible they may have also made one or two observations of the suns 
> elevation and plotted it to cross check their dead reckoning information 
> before visual sighting of land masses. Never did like the term "Dead" 
> reckoning. :-) 
> 
> breck k4che 
> 
> | On Dec 2, 2007, at 9:15 AM, Francesco Ledda wrote: 
> | 
> |> 
> |> I am sure that it was compass, watch and a little luck.... 
> |> 
> |>@mailman.qth.net