This was in the December 1938 issue of Popular Science. A "safety plane" whose only purpose was saving lives, I suppose - like Mussolini's for example, in its most famous operation?
The Guggenheim Safe Aircraft Competition was launched in 1927 by the Daniel Guggenheim Fund for the Promotion of Aeronautics to offer $150,000 in prizes for safer, more practical aircraft design. [1, 2]
Key Details of the Competition
Purpose: To challenge aviation manufacturers to build an airplane that was virtually "foolproof" and un-stalling without sacrificing speed or performance. [1]
Strict Criteria: Entries required reliable powerplants, structural soundness, high pilot visibility, good stability, maneuverability during engine failure, and strict takeoff/landing distance limits. [1]
Judging Panel: Chaired by aviation pioneers including Orville Wright and Richard E. Byrd. [1]
Winner: The Curtiss Tanager won the grand prize after successfully passing all grueling flight and safety tests, narrowly beating the British Handley Page Gugnunc
I've gone for a ride in a Helio Courier.
Looking at the wiki it was probably this:
H-391B Courier N10CJ 1958 Helio H391B Courier | PacTex Aviation
Production version of H-391, 102 built
Or maybe an ex air force U10.
The automatic slats are cool and a bit scary on a first ride. As you raise the angle of attack they get a bit nervous, then they bang on out to the stops with an audible clank. It is always a bit asymmetric, one side then the other.
Then it can come down very steeply, and Bean < the owner> had to give it a pretty decent stab of throttle to stop the elevator trip or it would be a very hard arrival.
The Socata Rallye had similar automatic slats.