A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2019 Apr 22, 20:47 -0400
Regarding Noonan's drinking and dismissal (or "strongly encouraged resignation") from Pan Am, this has been widely reported. The three seminal texts that I can think of about that era are "China Clipper - Age of the Great Flying Boats" by Gandt, "Chosen Instrument" by Altschul and Bender, and "Captain Lodi Speaking" by Marius Lodeesen. They're all pretty clear about Noonan's drinking and that it was the reason for his separation from Pan Am.
There are also reports that, partly because of his drinking, Noonan was not Earhart's first choice of navigator for her trip. We know he was not her first navigator, anyway.
The following website belongs to a bit of a conspiracy theorist so I wouldn't ordinarily consider it informative (he's certain Earhart crashed on Mili for one thing), but this article actually does a nice job of bringing together many accounts of Noonan's drinking in one place, quoting and citing sources, so it's useful in this case:
Note that I'm not saying Noonan's drinking had anything to do with their disappearance. There are conflicting stories about him drinking in Lae, but nothing definitive, so probably we'll never know. As far as his separation from Pan Am though, it's pretty clear.