Branson said Saturday that his engineers insisted planes could have flown without any danger from the ash, spewed by Iceland's Eyjafjallajokull (pronounced ay-yah-FYAH-lah-yer-kuhl) volcano.
Flights across Europe were grounded for several days, causing chaos for travelers and businesses. Branson said his airline lost 50 million pounds ($77 million).
He says Britain's government has now "accepted that there was overreaction," and called for airlines to be compensated for their losses.
British airspace was closed for six days. Authorities say Europe is now almost completely free of volcanic ash.