"Sky King" is one of the first television shows I remember watching, so it has great nostalgic value for me. I'd love to see it again, since it has been 50 years since I last watched the program!
I do remember the character "Penny," probably more than I remember "Sky King," although the name Kirby Grant (Sky King) was always remembered and I couldn't have told you who played Penny until I read the title page here at IMDb. I do recall Gloria Winters (Penny) has a wholesome, cute blonde. I've read some reviews that say she is annoying in this program, but I can't recall that.
A cowboy who flew airplanes - now that was a different angle for a storyline! This was an adventure program that was a favorite in our family, too, as my father always had interest in flying and eventually was able to buy a small plane - a Cessna, similar to the one Sky King flew!
I'd sure love to see some episodes of this again, although I don't know how they would look today. I am encouraged that some of these are available on DVD. One thing for sure: you can't beat the good messages that television shows brought to us families in the '50s, unlike the garbage you see today.