How expensive would it have been to get a second door certified? I wonder
why nobody has developed a second door STC if it is so desirable and easy
to
do. The whole success of the Cherokee line was based on commonality of
parts and low cost.

Right, but see EDR's post. Who cares how expensive the endeavor is, if it
means you'll sell three times as many planes?

On the other hand, there's no guarantee that a second door would have
guaranteed this result -- but for many "less sprightly" pilots, the single
door is a real handicap.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"