I understand why David Billings believes that the plane ended up on New Britain, that note from the army patrol is very compelling evidence. I would like him to convince me but he has yet to show a plausible way for the plane to have enough fuel to fly that far. In 2013 we discussed this on a different forum, skeptoid, and I posted the following. I asked Billings to respond to it on line or by email (and I gave him my address) but he never responded to this. Maybe he will respond here.
gl
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"Gary LaPook says:
June 9, 2013 at 3:13 am
David, there are a number of problems with you analysis. i will get into them in more detail later but a few initial points.
Earhart’s original plan was to fly non-stop from Hawaii to Tokyo, a distance of 3,860 SM so the plane was designed to cover that distance and originally had tanks holding 1200 gallons. The report on page 6 contained this warning:
“(3). The Cambridge Gas Analyzers should be carefully calibrated
in flight to see IF the fuel consumption data used in this
analysis CAN BE obtained. This should be done before at tempt–
ing any long range flight .”
https://www.dropbox.com/s/tavt14xwlvws84f/Page%206%20from%20Report%20487%20original.pdf?dl=0Apparently it could NOT be shown that the fuel consumption could be gotten down to 0.42 BSFC which was required for the range estimates as shown on page 13 of the report. Earhart then realized there was not a sufficient reserve to make the flight as planned so explored the possibility of being refueled in mid-air over Midway island but the Navy was not too hot on this idea. When Earhart’s buddy Gene Vidal come up with building a runway on Howland the plan was changed so this extreme range was no longer required so one large tank was removed and replaced with a smaller one making the total capacity 1151 gallons. As to the accuracy of the report, the takeoff data was confirmed by the recorded takeoffs so the report is most likely as accurate as it could be especially since it did not guarantee the estimated range values IF the estimated fuel BSFC values could not be achieved and proven in flight.
https://www.dropbox.com/s/rz142ig9ne300au/Page%2013%20from%20Report%20487%20original.pdf?dl=0You believe that somehow she could achieve these unrealistically low fuel consumption rates but the lowest BSFC (BRAKE specific fuel consumption) ever claimed by Pratt & Whitney for this engine (the people who built the engine and who had every reason to claim the lowest possible fuel usage rate so that they could sell more engines) was 0.46 pounds per hour per horsepower not the 0.42 that Kelly Johnson hoped to achieve in report 487. And that is at the optimum power setting, the fuel consumption rate gets WORSE at lower power settings. Look at page 34 of the report, at 250 brake hp the BSFC actually gets slightly worse, 0.47 lb/hp/hr.
https://www.dropbox.com/s/9j9iyeaji7uayk3/Pages%2032-34%20from%20Report%20487%20original-annotated.pdf?dl=0You have made some other mistakes in you reliance on report 487. You claim that Earhart stated that she got the fuel flow down to 20 gallons per hour total (ten gallons per hour per engine) and you claim that the power required graph on page 28 shows that at the 120 mph that Earhart claimed that the power required was 250 hp total requiring a total fuel flow of just about 20 gallons per hour and thus confirming Earhart’s statement. If your interpretation of this graph were correct, then it would provide confirmation of your interpretation of Earhart’s statement. Unfortunately, there are three problems with your reading of this graph.
https://www.dropbox.com/s/8uzhchmiyz4l3eg/Page%2028%20from%20Report%20487%20original.pdf?dl=0First, Earhart stated that her “indicated” airspeed (IAS) was 120 mph at 10,000 feet. According to my E-6B, 120 mph “indicated” airspeed at 10,000 feet at standard conditions makes the “true” airspeed (TAS) 140 mph. Looking at the graph on page 28 (I have the original graph, there is a problem with the copy provided by TIGHAR as the lines on the graph paper do not line up correctly, I could send you a copy if you like) the power required for 140 mph true airspeed at 10,000 feet is 296 horsepower. Using the P&W BSFC of 0.46 means that the fuel flow was,at a minimum, 22.8 gallons per hour. Not a big discrepancy so far.
[In case there are any non-pilots reading this, the airspeed indicator reads less than the aircraft's true airspeed due to the thinner air at altitude. An "E-6B" is a standard circular slide rule that has scales used to correct the "indicated airspeed" for the thinner air so that the aircraft's "true airspeed" can be determined. The graph on page 28 and 27 show the thrust horsepower required for various true airspeeds.]The second problem is that the power required numbers on page 28 are NOT brake horsepower but are “thrust” horsepower. Since the propeller efficiency is only 75%, the brake horsepower required is 33% greater making the brake horsepower required for 140 mph TAS 393.7 BRAKE hp. Again using the P&W BSFC of 0.46 lb/hp/hr means that the fuel flow was, at a minimum, 181 pounds per hour, 30.2 gallons per hour.
The third problem with using the information from the graph on page 28 is that that graph is for a gross weight of 9,300 pounds and we know the plane weighed at least a thousand pounds more at that stage in the flight. If you look at the graph on page 27 for a gross weight of 12,900 pounds you will see that the thrust horsepower required is 412 making the brake horsepower 548, the fuel flow 252 lb/hr, 42 gallons per hour so we know that the actual flow noted by Earhart had to be between these numbers, between 30.2 and 42 gallons per hour. Another way to look at this is to just apply normal aerodynamics which show that the power required varies with the weight ratio raised to the 1.5 power. The plane, at the time that Earhart reported “less that 20 gallons per hour” weighed about 10,500 based on its fuel and oil load at the time of takeoff from Oakland and based on it carrying four people, NOT just two, plus their baggage (Mantz was planning on spending time with his girl friend in Hawaii) and all the equipment and spares listed in the Luke Field Inventory. 10,500 / 9,300 equals 1.13, raised to the 1.5 power makes 1.20 so the brake horsepower would have been 1.20 X 393.7 = 472 BRAKE horsepower and the fuel flow would have been 36.3 gallons per hour, a little less than 20 gallons per hour PER ENGINE. It appears that Earhart was actually reporting the fuel flow PER ENGINE, not the total fuel flow.
https://www.dropbox.com/s/hiy93jipgkp918s/Page%2027%20from%20Report%20487%20original-2.pdf?dl=0You have also misunderstood the information shown on page 33 of the report. You claim that this table confirms the 250 hp required for 120 mph airspeed so supports the fuel flow reported by Earhart. Didn’t you notice that this table also shows the same 250 hp for an airspeed of 140 and 160 and 180 mph? How does this make sense? If 250 hp could make the plane go 180 mph then why wouldn’t Earhart use that higher speed since it could be obtained with the same power setting and fuel flow, thus improving greatly the range of the plane?
The answer is that the numbers in this table are used to plot the “power available” not the “power required” curves on the graph on page 28. You interpreted the 250 hp as the power “required” which is completely wrong. You can check this for yourself, look at the tables on pages 31 through 33, double the shown horsepowers available, and then plot them on the page 28 graph and you will see that you have simply drawn int the “horsepower available” curves."