It is possible to ride the Pelican. At the part where black bars appear and one says "If You Want It Done Right...", continue as usual. You can stop at the second tower and obtain the Thunderstorm skull if desired. When you reach the third tower, there should be a Phantom and some Banshees. Blow them up. The Pelican should advance towards the tower. Park the Hornet on it and hop out. The Pelican will probably throw you off the first few times. If you are playing in Co-op mode, you can have you friend park his Hornet on the ground near the tower to the left. If you are skilled enough, jump from the Pelican to the Hornet.