After the survivors' eventual death, the Flash sideways was opened up where an Oceanic Flight 815 carrying many of the passengers from the original Flight 815 lands safely at LAX. Many of the original conditions of the Flight 815 flight still occurred, including the turbulence that originally led to the plane crashing. However, in this timeline, the island was underwater for unspecified reasons, thus making it impossible for Desmond to fail to push the button, saving the flight from crashing. The plane was still flying on the correct bearings to pass over the island, however, as the island was revealed beneath the plane, deeply submerged.
Some of the original conditions of the flight and its passengers were altered in this timeline including:
Jack received one bottle of alcohol from Cindy instead of two.
Jack, Rose and Bernard sit in row 24 instead of row 23.
Jack was nervous from the turbulence instead of Rose.
Jack's hair is much longer than on the original flight. On the original flight, his hair was closely shaved.
Bernard returns from the bathroom and takes his seat beside Rose.
Shannon was not on the flight, and did not return to Los Angeles with Boone.
Desmond was on the flight, instead of on the Island.
Hurley was blessed with good luck instead of bad.
Charlie was found unconscious, choking on his heroin, instead of tossing it in the toilet bowl. He also bears a different appeance with much shorter hair.
Jack's father and his coffin were never put on this flight, and were instead lost "in transit".
Jin and Sun are not married. (Sun is called Ms. Paik instead of Mrs. Kwon, and neither Jin or Sun are wearing their wedding rings.)
Unseen passengers from original timeline
It is not known if the following passengers from the original timeline were also on the flight in the flash-sideways.
The outside appearance of the Flight 815 plane is noticeably different to the one that crashed on the island in the original timeline.
The original Flight 815 plane is white with three blue stripes running along the side and has a dark blue belly; however the plane in the alternative timeline is just white with the blue stripes.
The logo on the side of the plane is also slightly different. In "Pilot, Part 1" the Oceanic logo on the front section of the plane cuts into the three blue stripes on the side of the plane more than it does in LA X.
On the original Flight 815, the plane's left wing was visible directly outside of Jack's window. This is not the case in the flash-sideways 815, indicating his changed seat.