Great white sharks do not eat killer whales, and it is, in fact, the other way around. Research has shown that the screams of killer whales have been known to drive away marine life, like great white sharks, hammerheads and even dolphins from different environments. This is because killer whales have been known to prey on sharks of all types and species.
Killer whales hunt sharks by flipping them upside down. When sharks are flipped upside down, they go through a paralyzed state that is better characterized as tonic immobility. Tonic immobility is an unlearned reflex that causes the sharks' muscles to relax and causes sharks to go into deep rhythmic respiration. Tonic immobility typically lasts for 15 minutes before the sharks are able to turn themselves upright once again. During this brief amount of time, sharks, even great whites, are vulnerable to the attacks of killer whales.
Killer whales are much larger than great white sharks, as males can reach up to 32 feet in length and can weigh up to 9 tons. Male great white sharks reach a maximum of 20 feet in length and can weigh up to 5,000 pounds. Killer whales are also much faster than great white sharks, and typically hunt in large groups.