@ CONSO...
Thanks for the suggestion Conso but with this "complicated" problem there are too many variables and unknowns involved, including the 'impulsiveness shown and apparent in the mind of Earhart '....
After increasing the size of the MS Excel file to accommodate all the increments of weight and speed and then to include anther twist would tax me beyond comprehension !
What I am beginning to think is that Earhart set the power at what she thought was the right "amount" for the longest flight attempted which was only two hundred miles more than the SFO to Hawaii flight made earlier in the year and she had successfully "been there and done that".
Where the Electra arrived at after 19 Hours and 12 minutes (1912 GMT) all hinges on the meaning of "must" in "...must be on you".... that questioning and tantalising word "must" in that phrase says an awful lot for such a short word. In hindsight we know they didn't get there and Noonan surely would have known that they were not there....
Back to the plot.