After the clip, head to the back of the Studio and get into the seaplane.
You'll have a set of blue checkpoints appear around Vice City. Pick any one of these you
want, and fly into it. This will start the flyers being dropped. Any remaining blue checkpoints
will disappear, and a single red checkpoint will show up. Fly towards and into the red checkpoint
to stop the flyers being dropped, and to display the remaining blue checkpoints.
Do this for each blue checkpoint in the missions, until all the checkpoints have been cleared,
and all the flyers distributed.
You have only a limited amouut of fuel in the plane, so don't take to long. However, you have
more than enough to last this missions, if you don't miss the checkpoints to many times. You want
to ensure you don't damage the plane more so than you do about speed.
If you time it so you attempt this mission later in the evening, you'll find it easier
to see the checkpoints.