Aviation Week reports:

Although it was initially slated to debut this year, SpaceX founder, CEO and Chief Designer Elon Musk says the company’s production schedule is too tight to support a test flight of the heavy-lift rocket from Vandenberg AFB, Calif., in 2014.

“We need to find three additional cores that we could produce, send them through testing and then fly without disrupting our launch manifest,” Musk said in a Feb. 20 interview. “I’m hopeful we’ll have Falcon Heavy cores produced approximately around the end of the year. But just to get through test and qualification, I think it’s probably going to be sometime early next year when we launch.”