Go to forge and pick Sandtrap. Buy/get a Warthog and cram it in the "cockpit" of the elephant. Let it settle inside and make sure its tight. Grab a hold of the warthog and quickly go to the front of the cockpit (while still looking at the warthog). Now slowly go up. If done correctly the elephant should be in the air for a sufficient time.

P.S. when up in the air stay in the roads.