Plane Crazy was created in complete secrecy at the Walt Disney Studio. At the time of its creation, Charles Mintz had just gained the rights to Oswald the Lucky Rabbit as well as convinced Walt's staff to walk out on the studio, leaving only Ub Iwerks. Walt decided to launch a new character, that of Mickey Mouse, by creating a new cartoon to interest potential distributors. Iwerks actually drew the entirety of Plane Crazy with Walt and Roy Disney's wives, Lillian and Edna, inking and painting (along with Walt's sister-in-law Hazel Swell).
The toon premiered May 15, 1928 at a theater on Sunset and Gardner in Hollywood. It seemed to be received well by audiences; the trouble was distributors panned Mickey or just never saw the toon. Without a distributor, Walt couldn't afford to make a Mickey Mouse series.
It wasn't until later in 1928 that Mickey and Minnie gained their stardom thanks to sound and a steamboat named Willie. Now that his characters were popular, Walt wisely re-released Plane Crazy with sound on March 17, 1929, and it suddenly became a hit.
Plane Crazy is a simple toon involving Mickey flying an airplane. Mickey's design was created by Ub Iwerks, and as you can see it's very different from today's version. Here Mickey has no gloves nor shoes, though he does wear his trademark shorts. His eyes are interesting because they include pupils; this of course changes with Steamboat Willie where he is seen with oval, button-like eyes.
So, he builds a plane and of course asks his girlfriend Minnie to take a ride with him. Here we see the first design for Minnie Mouse, which doesn't differ too much from Mickey's. In subsequent cartoons she will gain shoes, gloves, and a flowered hat (from time to time). Her eyes will also make the change to oval buttons in Steamboat Willie. An interesting fact here is that Minnie says the only words in the toon, "Who, me?". Her voice was provided by Walt himself.
Now, while watching Steamboat Willie, I believe Minnie does yell "yoo-hoo" while running to catch the boat; then again, she could just be making a noise that sounds like "yoo-hoo". For that reason, it's hard to tell whether or not her line here is the 1st or 2nd time she speaks.
Besides being Mickey and Minnie's very first cartoon, Plane Crazy is also notable for being the first animated film to use a camera move. As Mickey loses control of his plane, he runs down a cow. To achieve the shot, the Disney animators piled books under the spinning background to move the artwork closer to the camera, thus creating a sense of moving in.
Plane Crazy shows the raw side of the Mickey shorts, before he was refined to become the Disney corporate symbol he is today. Gags like turning animals into machinery or instruments are my favorite in these early films because today they are simply not seen.
While watching Plane Crazy, it's easy to see the untapped potential in the two mice. Who at the time could even guess at the characters' future popularity?