Brace for emotional impact. After US Airways Flight 1549 fell out of the sky and landed in the Hudson River, there was still a harrowing survival story we didn’t get to see.

Captain Chesley “Sully” Sullenberger was credited with saving the lives of all 155 passengers aboard the jet that plunged into the icy river on Jan. 15, 2009, but the upcoming Clint Eastwood-directed drama Sully, starring Tom Hanks as the real-life pilot, focuses on the way a hero is sometimes tested after the fact.

“People saw the landing, but what followed is where the conflict is,” Eastwood tells EW. “There was an investigation into his decision and it was painting a picture that he had done the wrong thing, that he could have made it back to La Guardia or Teterboro. What happened behind closed doors is what most people don’t know.”

Although the word “hero” is one that’s often used to describe Sullenberger, Eastwood’s films tend to tend to narrow their eyes at that concept. In this case, the filmmaker says the pilot’s grace in the midst of a nightmare scenario makes him worthy of respect.

“Sully kept his wits about him when everything was going wrong and negotiated the problem without panicking and that takes a superior person. I can see why he became such an iconic figure,” Eastwood says. “He’s the kind of guy that can walk into a room and instill confidence that everything’s under control.”

He got to know the real Sullenberger during production, which inspired Eastwood’s first pairing with Hanks. “Before Tom was cast, I visited with Sully and his wife in their home to get an impression of him. I was making a list in my mind of people who could possibly play him, and Tom was right there,” Eastwood says. “Tom and Sully spoke on the phone several times before Tom went up to meet with him. Sully also visited the set and was a great resource.”

Sully co-stars Laura Linney as Sullberger’s wife, Lorraine, and Aaron Eckhart as his co-pilot, Jeff Skiles. The film is produced by Frank Marshall, Allyn Stewart, Tim Moore, and Eastwood, and it’s set for release Sept. 9, 2016.