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Ric Gillespie

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letter to FLYING
« on: September 25, 2020, 11:46:56 AM »

I sent this to the editor of FLYING magazine.

I was disappointed to read Peter Garrison’s article “Earhart and Range” in the current issue of FLYING.  Mr. Garrison bases his analysis and commentary on the 1999 report “Details Concerning Analysis of Amelia Earhart’s Final Flight - July 2, 1937”  by G. Swenson and F.E.C. Culick at the CalTech Jet Propulsion Center.  While the calculations presented by Msrs Swenson and Culick are valid and correct, the data upon which they are based are not and their conclusions are a classic case of garbage in, garbage out.  Among the many factual errors Mr. Garrison repeats:
• He alleges a 26 mph headwind over Earhart’s entire route.  The claim is unsupported by the available evidence and based upon a single radio message from Earhart heard at Lae, New Guinea seven hours eighteen minutes after her departure.  There are two sources for the content of the message. In a letter written July 25, 1937 by Eric Chater, manager of Guinea Airways, reported she said, “Position 4.33 South 159.7 East, height 8000 feet over cumulus clouds, wind 23 knots.”  No wind direction was mentioned. A letter written August 28, 1937 by James Collopy, District Superintendent Civil Aviation, quotes Earhart as saying she was at 7,000 feet, making 150 knots.  The CalTech scientists appear to have been unaware of, or ignored, Collopy’s “making 150 knots”, assumed Chater’s “wind 23 knots” was a headwind, and extrapolated it to span the entire 2,500 mile trip.
• The Caltech report, and Mr. Garrison, correctly note that Lockheed’s Kelly Johnson provided Earhart with guidelines for power, fuel and altitude management for her March 17, 1937 flight from Oakland to Honolulu, but they also imply those guidelines included recommendations for handling headwinds and tailwinds.  They did not.  Power changes in the event of headwinds and tailwinds are addressed in Lockheed Report 487 “Range Study of Lockheed Electra Bimotor Airplane,” a highly technical treatise published in June 1936. Report 487 also recommends 30° of flaps on heavily overloaded takeoffs, a suggestion Earhart did not follow.
•  Mr. Garrison says that, to overcome the supposed headwind, Earhart increased her true airspeed by more than recommended to 140 knots, or approximately 161 mph. The allegation is based on a message heard at Lae four hours and eighteen minutes after departure in which she reportedly said, “Height 7000 feet, speed 140 knots, everything okay.”  Earhart’s airspeed indicator read in miles per hour, not knots.  Silly as it seems to Mr. Garrison, navigators work in nautical miles and knots.  Earhart’s “speed 140 knots” was most logically a ground speed calculated by her navigator Fred Noonan.

The are other factual errors and misconceptions in Mr. Garrison’s piece too numerous to mention, but without the imaginary headwind his “obvious and prosaic” explanation for Earhart’s disappearance crashes and sinks. The documented facts of the case lead inexorably to one of the “thousand fanciful alternatives” he so confidently dismisses.  A fact-based solution to the Earhart mystery can be found at TIGHAR.org.
 
Richard Gillespie
Executive Director
TIGHAR.org
tigharic@mac.com
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Christian Stock

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Re: letter to FLYING
« Reply #1 on: September 25, 2020, 12:40:34 PM »

It's just another illustration of the folly of modeling the flight based upon the limited information available. They all start with "the wind was x". What if it wasn't?

Too many unknowns.
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