Fred Noonan was Amelia Earhart’s navigator on her “Around The World” Flight in 1937.

Before that Fred Noonan was one of the earliest flight navigators at Pan American Airways.

https://en.wikipedia.org/wiki/Fred_Noonan

https://timeandnavigation.si.edu/multimedia-asset/fred-noonan-navigating-a-pan-am-sikorsky-s-42

https://earharttruth.wordpress.com/2014/12/23/fred-noonan-amelia-earharts-forgotten-navigator-2/

https://tighar.org/wiki/Air_Navigation:_State_of_the_Art_in_1937

Here is an internal Pan Am memo where Fred describes his navigation during the 1935 survey flight from California to Hawaii:

https://tighar.org/Projects/Earhart/Archives/Documents/Reports/NoonanPanAm.pdf

Below is an interesting letter from an ex-Pan Am employee who both praises Fred’s navigation skills but goes on to say that Fred left Pan Am because of drinking (a commonly-held notion).

Below is a letter from George Palmer Putnam (Amelia’s publicist and husband) wanting to meet one of the best Pan Am navigators:

Harry Manning was originally to be Amelia Earhart’s navigator and radio operator, but this happened:

So Fred Noonan was added and Harry Manning left the team after Amelia wrecked her Electra in Hawaii because it took over 2 months to repair and Harry, on temporary leave as Captain of the cruise ship SS Roosevelt, had to return to his day job... so Fred Noonan became Amelia’s only navigator, and Amelia lost her only qualified radio operator (Manning).

So why did Fred Noonan actually leave Pan Am? Ironically it may have been radio and Hugo Leuteritz’s work on high frequency radio direction finders at Pan Am, and Fred’s navigation being bested by this new system on at least one occasion.  The following document below was found in the Leuteritz Archives at the New England Air Museum (NEAM) among other bibliographical notes dictated to his wife Paula Leuteritz (“P.L”):