wrote:

PS Now for the bonus question. How could one get an airplane CFI
certificate without ever flying a retractable gear airplane?

I can see two possibilities: i) grand-fathered in from a time
when you could get a commercial without flying a complex aircraft
(but then I haven't checked the historical regulations); or, more
likely: ii) did all his training, commercial and CFI, on floats...

--Sylvain