The Ercoupe was the only airplane where all of the ideas in "Stick and
Rudder" were implemented. The rudderless Ercoupe was not a complete success;
many of them have since been modified by adding rudders. The ideas in "Stick
and Rudder" also influenced the development of several other aircraft,
including the Cessna 172. Fortunately, the Cessna Aircraft Company had some
genuine engineers working for it; they managed to keep the wierd stuff out
of it. I regard the Cessna tricycle gear line as the best implementation of
Langewiesche's ideas, if not the most complete. More modern attempts to
create stall-resistant aircraft include the Cirrus and Lancair.

Fans of the Ercoupe claim it will not stall. This is only a half-truth at
best. The Ercoupe can be maneuvered into a stall. It can also develop a
remarkably high sink rate that is a pretty darned good substitute for a
stall. The Cirrus and Lancair will stall as well, as has been demonstrated a
few times. The Cirrus will not recover from a spin, but it can be forced to
enter one.

"Stick and Rudder" is not the revealed word of God on the subject of
aviation. There are mistakes in it, as well as some rather odd theories. The
bit about the rudder is just one of them. In fact, the aerodynamics
throughout the book are more than a little suspect. Neverhtheless,
Langewiesche makes some good points. He was often right in what should be
done, but just as often wrong in how. It is obvious that Langewiesche
understood almost nothing about how air flows around an airfoil. He knew
that airplanes stall when they rich a critical angle of attack, but I see
little evidence that he understood why that is so.

There are better books about flying. "Stick and Rudder" is valuable for its
historical insights into the development of modern aircraft, but little
else.