Riding a Pelican

Watch YouTube video on how to "Ride a Pelican" 8s1o7HKmPFA

On some levels it's possible for a player to climb or jump on top of a Pelican and ride the ship to its destination, thus, Riding a Pelican.

Walkthroughs
POOOOOOOOOOOO HEAD!!

Metropolis
Play through the Metropolis (Level) until you get to the part where you're in a Gauss Warthog with another Warthog riding alongside you (your situation may be slightly different, but that's what is meant to happen). You come into a street with a couple of Jackal snipers, two Wraiths, and a couple of Ghosts. Another Wraith and two Phantoms come momentarily, followed by two Pelicans.

Notice where the Jackal snipers were standing: raised areas between the streets. Go to the far one. This is the point where the Pelican will drop off some marines for you. Be at the top of this area before the Pelican begins its descent.

As soon as the marines have exited the Pelican, jump toward the passenger bay and hold the X button. Aim for the bottom of the Pelican, right near the back entrance. An easier way to do this is to hijack a wraith and place it where the marines are dropped off, climb on the wraith and wait for the pelican. This should allow you to climb in the cargo bay and go for a ride.

After a short trip, the Pelican falls to the bottom of the level. In Halo: Combat Evolved, a free-falling Pelican would travel the exact same path every time, but things might be different here. Occasionally,in co-op mode, everybody landed on a giant concrete platform (too far down to get back into the level, and too far up to continue to the very bottom). The Pelican continued its way down, while you and the marines were stuck there. Sometimes instead of landing on the giant concrete platform, you land on a invisble platform which is below the giant concrete platform

You can have some fun here if you have a few Marines. The Pelican will keep spinning around but will eventually come to a stop. Walk against one of the marines until you get him/her "under" the Pelican's nose. Go to the opposite side of the Pelican and press X to flip the Pelican. Either it will send the marine flying, or crush him. You can do this to yourself too.

Outskirts
Also, if you jump onto the rooftops at the beginning of the Outskirts (Level) and completly blow off the battle in the first part, a checkpoint will appear and Sergeant Johnson will spawn and begin boarding a Pelican which will also come. If you jump onto the Pelican it will fly off with you on it. You won't get far though because it disappears in mid-air!

Delta Halo
Another example is on the level Delta Halo, where you continue as normal until the pelican comes in and drops off the Warthog. Get to where the Shade turret on a small hill was and then wait for the Pelican to come to a halt. Then Grenade jump up to the Pelican. It will fly around with you on its back and then move forward faster making you drop down to your death.

Assault On The Control Room
At the beginning of the level a Pelican will drop you of and as soon as you are droped of it will say " HOLD X TO RIDE PELICAN". If done successfully you will be able to ride it for a short time. At the end of the ride though you will die. Although it is possible to survive if you are playing on co-op mode and one person gets out of the Pelican.

343 Guilty Spark
At the beginning of the level, when you are still in the Pelican for a few seconds, if you throw a grenade out of the Pelican you will stay inside the Pelican and it will fly around the map, eventually going into the hills and hovering there for the remainder of the level. The hills span around the perimeter of the map and if you go around them you will eventually find a Marine with a boonie hat and no weapon who just stands there and does nothing.

Pelican rotates, passing through solid ground
Watch the Pelican spin and pass through solid ground (Around 50sec mark) NPhKsY9ZLHY If you manage to get to the bottom (blue area), you notice two pretty interesting things. The first is that the Pelican lands facing up, or keeps rocking back and forth until it looks straight up. The second is that when you walk up to it, it says, "Press X to flip Banshee." even though the vehicle is a Pelican and not a Banshee.

Then if you press X it flips end for end and if you time it right it will hit you and send you flying into the air. The Scarab Gun cannot be obtained if someone gets hit by the pelican. The one on top of the bridges is too high up (even if the Sputnik skull is activated) and too (horizontally) far away. The fall timer would kill anyone trying to get the other scarab gun.

Also if you are lucky you can get the Pelican to end up as though it had landed perfectly, you can get into it and go all the way through to the pilots seat and press X. You can now fly the Pelican as though it were a Banshee. It looks pretty cool having a pelican doing barrel rolls and flips!!

Head Stuck In Ceiling
Looking at the Pelican in Metropolis that you can ride from the back, if you get in on the right side your head will be stuck in the ceiling and you will not see your weapon, however, you can still look around.