Rob Gluckman shot this video of Helitanker 731, an Erickson Air-Crane, taking off and dropping a load of water. It may have been recorded at Van Nuys Airport. Mr. Gluckman wrote this when he posted it on Facebook:
Was lucky enough to catch this monster spooling up at the same time we were. Unique perspective on the ground and in the air. Air Crane is fully loaded! Look at those blades cone!!