Originally, the role of Baloo was supposed to go to Phil Harris, who had voiced the character in The Jungle Book (1967). But after several recording sessions, it was found that Harris (who was then 85 years old) had aged to the point where he couldn't do the voice successfully anymore, and also had to be driven all the way from his home in Palm Springs to the recording studio for each session. Harris was later let go of, and the episodes he had recorded for were redubbed with veteran voice actor Ed Gilbert, who took over as the role for the rest of the series.
The family of the late Louis Prima (who voiced King Louie in The Jungle Book (1967)) sued Disney because Jim Cummings did too good of a job impersonating Prima when he voiced the character in this show. As a result, King Louie was completely absent from The Jungle Book 2 (2003) and was replaced by King Larry in House of Mouse (2001), the twin brother of Louie (also voiced by Cummings).
DuckTales (1987) co-creator Jymn Magon always meant to develop a new series featuring Baloo as the main character and he simply melded that onto an unused idea from DuckTales (1987) about an air cargo service. The word "Tale" from the title and references to fowl in the aircraft names are a carryover from DuckTales (1987).
Many of the planes featured in the series have real-life analogies: the SeaDuck is a Conwing L-16 Heavy Transport with Superflight 100 engines, similar to a Fairchild C-119 Flying Boxcar; the CT-37 Pirate Fighter is based on the Gee Bee Model R Super Sportster with a second pair of wings and pontoons instead of landing gear; and Louie's midair refuelling plane is analogous to the Grumman G-21 "Goose".