Originally Posted by
David Billings
@CONSO:
That "Solver" method sounds as if it could be harder work than doing it by my "manual" MS Excel method where I can bury formulae in the cells and run actual equation checks every so often just to make sure I'm in the ball park of where the Radio transmissons and timings are.... Very interesting if the Solver comes up with what i have though !
@propertee64:
The tabulation that I put into the website is not the actual working file of the "MS Excel" method, if that was printed ipn A4 sheets of paper it would run for about 30 pages, the one i have on the website is a MS Word "contraction" of the results from Excel and is for 14,700 lbs AUW. I have also done a 15,000 lb AUX MS Excel file. You might say, "Why do that because if she can get back to East New Britain on a fuel load of 1100 gallons, surely she would be able to get back with another 300 lbs of gas (51 USG) ? It doesn't work that way though, the extra 300 lbs of gas has to be 'carried' all the way out into the Pacific which means a slight power increase requirement to get it there.....
The Weekend Australian article:
I am told the Earhart article about our project and efforts is to be printed in this weekend's edition of The Australian newspaper, i.e: on Saturday 14th July.
RE THE SOLVER ISSUE
The 60 rows of data are 58 identical rows via copy and paste ( with a few anchor values )- trivial to do in excel. only about 3 to 4 colums contain anything but simple math and max- min data. Currently about 10 variables
are considered or needed or involved, such as GVW at takeoff, GPH gas, IAS start or needed to get range max, time and milage at Ontairo and Num, and wind at three segments. The rows can easily be expanded to cover time increments of your choice, currently using half hour increments which can easily be changed to hour, quarter hour or 1/10 hour, with corresponding number of rows needed to cover probable results and time. Currently i'm using .5 hour increments which seem which seem to fit a carefully derived curve-plot data based on LAC data of GVW- versus GPH. Although not complete with my cross checking and verification of ' reasonable/likely/ probable results, I will shortly list here my Solver solution based on ' near zero ( plus or minus 10-15 gallons ) gas and /or remaning miles to ' crash ' site and likely wind data. It took a close look and careful analysis of the LAC 487 page 8 figure II data to properly relate GVW versus IAS versus GPH data on page 34. The result was the use of two curve fit routines which had a match point off 11020 GVW and 39.8 GPH at IAS speeds between 128 and 148 mph. Currentlty I'm working to provide a simplified training Solver analysis of page 7 figure 1 data to show how it works and the results. I've found that a simple two equation curve, transitioning from an exponential curve at GVW above 11020 and a straight at less than 11020 GVW give very good matching results for zero wind. The remaining issue is to determine most likely transition points probable for wind speeds and probable IAS speeds used. I'll publish the curve-data I have so far for your 14,700 and 15,000 GVW at takeoff with ' reasonable wind ' data, range results and probable turnaround milage.
Conso
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