The Flight 93 National Memorial will receive part of the box-office revenue from the new movie about the airliner hijacked during the Sept. 11 terrorist attacks.

Writer-director Paul Greengrass' "United 93" will open April 28 and Universal Pictures will donate 10 percent of the first three days' grosses to the memorial, the Families of Flight 93 announced Thursday.

Gordon Felt, whose brother Edward was a Flight 93 passenger, said the studio's efforts "to help permanently memorialize the bravery of the 40 passengers and crew of Flight 93 who chose to fight back in the face of violent adversity are remarkable." Last year, the official 9/11 Commission report said the hijackers crashed the plane as passengers tried to take control of the cockpit.

Chris T. Sullivan, who heads a $30 million fundraising campaign for the national memorial, said he hopes "United 93" will result in worldwide support for the proposed monument in a field near Shanksville.

"United 93" chronicles in real time the hijacked United Airlines flight that crashed Sept. 11, 2001, killing all 40 passengers and crew. The film makes its world premiere at the Tribeca Film Festival in New York next month.

The winning design for the memorial was modified after some critics protested that its initial crescent shape symbolized Islam. The memorial's name also was changed from "Crescent of Embrace" to "40 Memorial Groves."