There is a gas station in the Little States that will give you unlimited fuel for free! It's located at a road junction in the southeast, between the space shuttle launch pad in Florida and the Mississippi River. Just land in the parking lot, between the sign and the building, and cross or touch the center line. Your fuel tank will get filled up automatically. If you're flying the gyrocopter, just be sure not to come to a complete stop, of the stage will end. 

The Birdman Stars:-  Holiday Island - Under the natural arch on the beach. Cresent Island - in a hidden cove on the beach, Little States Island - in Central Park. In New York Arctic Island - Deep inside the cave that is the source of the elaborate waterfall. Jump between the building you start on and the building in front. You will notice a doorway on the building in front. Go through this into the Nintendo building and out of the other doorway. You are teleported to near to the end of the level. You can get 100 every time. It is difficult to get in the doorway, so I worked out an easier way. Aim against the opposite building so as you bounce into or close to the doorway. This makes it easier.

Holiday Island:-  On holiday Island there is a small arch off the side of the island. Almost like a small tunnel. If you fly under it with one of the vehicles you'll see a star there. If you touch the star you'll be instantly transported to Birdman on Holiday Island . Also if you, CAREFULLY, fly into the small cave beneath the castle and fly back out you will find that it has become nighttime. 

Everfrost Island:  To reach the star here you have to first find the small area where there are a lot of small waterfalls. At the top of the waterfalls are two caves. Go into the one on the right and navigate through there to find the star. Also if you fly to the top of the highest peak you'll find an N64 flag. 

Little States: To find the star you must travel to New York City (Using the warp mentioned below). Once there, land in Central Park and the star will be there waiting for you. Also if you fly to San Francisco and find the teal (greenish-blue) building you can enter it with the rocketbelt. I don't remember which side to go in but when you come out of the other end (assuming you went in the correct side) you'll be in New York right in front of Central Park and the star.

In the "Little States" course, (the one of USA), SELECT the GYROCOPTER. Then enter the level and APPROACH the MT RUSHMORE SITE. Using the gyrocopter, SHOOT MISSILES at the head of Mario. If you manage to HIT HIM a FEW TIMES in a row, Mario's head will TRANSFORM into another famous Nintendo Character!

Pilotwings 64 tips and questions  -  There is a gas station in the Little States that will give you unlimited fuel for free! It's located at a road junction in the southeast, between the space shuttle launch pad in Florida and the Mississippi River. just land in the parking lot, between the sign and the building, and cross or touch the center line. Your fuel tank will get filled up automatically. If you're flying the gyrocopter, just be sure not to come to a complete stop, of the stage will end. 

The Birdman Stars  -  Holiday Island - Under the natural arch on the beach. Cresent Island - in a hidden cove on the beach, Little States Island - in Central Park. In New York Arctic Island - Deep inside the cave that is the source of the elaborate waterfall.

Jump between the building you start on and the building in front. You will notice a doorway on the building in front. Go through this into the Nintendo building and out of the other doorway. You are teleported to near to the end of the level. You can get 100 every time. It is difficult to get in the doorway, so I worked out an easier way. Aim against the opposite building so as you bounce into or close to the doorway. This makes it easier.

Holiday Island: On holiday Island there is a small arch off the side of the island. Almost like a small tunnel. If you fly under it with one of the vehicles you'll see a star there. If you touch the star you'll be instantly transported to Birdman on Holiday Island . Also if you, CAREFULLY, fly into the small cave beneath the castle and fly back out you will find that it has become nighttime. 

Everfrost Island: To reach the star here you have to first find the small area where there are a lot of small waterfalls. At the top of the waterfalls are two caves. Go into the one on the right and navigate through there to find the star. Also if you fly to the top of the highest peak you'll find an N64 flag. 

Little States: To find the star you must travel to New York City (Using the warp mentioned below). Once there, land in Central Park and the star will be there waiting for you. Also if you fly to San Francisco and find the teal (greenish-blue) building you can enter it with the rocketbelt. I don't remember which side to go in but when you come out of the other end (assuming you went in the correct side) you'll be in New York right in front of Central Park and the star.

FAQs
Who is the best character to use for each event?
Hang Glider: Goose
Birdman: Lark
Rocket Belt: Ibis
Cannonball: Robin
Gyrocopter: Hawk
Sky Diving: Goose
Jumble Hopper: Kiwi

Sometimes there are "balls" in the air. What are they for?

These are actually rings that haven't appeared yet. You must go through certain rings in order for them to open up, then you can go through them.

How many endings are there?

There are three endings. They are all the same, except each takes place during a different time during the day: 

Morning If you complete all of the regular Missions. 
Noon If you complete all of the regular Missions plus all of the Extra Games with Gold Medals.
Night The last ending is if you complete all of the regular Missions and Extra Games with perfect scores