Film där människor kan resa på tid för att återuppleva världens största katastrofer huvudpersonen ändrar ett öde, vilket sparar många människor

Jag tror att filmen du pratar om kallas Thrill Seekers (1999), det är också känt som Time Shifters .

Wikia säger detta.

Tom Merrick (Van Dien) works as a TV reporter when he's nearly killed in an accident while informing about a fire in the Evanston power plant. After directing his crew to take another position he spots a creepy-looking man, causing him to stay behind. This accidentally saves his life as the crew is killed in the partial collapse of a building.

After some time, he decides to do some research on catastrophes for a documentary he's preparing when he accidentally stumbles upon several pictures of the man he saw at the power plant (Richings), who appears to turn up in different disasters (sinking of Titanic, Hindenburg disaster and hurricane Hugo) as far apart as 50 years, but who still looks the same in all the pictures.

As his boss Eleanor hopes for a good story she books Merrick a flight to Washington, D.C. to get the original photographs from the author. When on the plane, he again spots the man from the power plant disaster and checks his luggage. He finds a flyer and discovers a futuristic enterprise—Thrill Seekers—will make time travel possible in the year 2070 and will sell trips to the past. These trips consist of travellers going straight to a catastrophe right before it happens, so they can experience the emotion but are able to travel back in time again before they get killed.

Huvudpersonen slutar använda kunskap om framtida händelser för att rädda människor, inklusive sitt eget liv.

Which is worse, Merrick finds out that the Flight 222 he is on will be involved in a mid-air collision, killing everyone on board.

Thanks to that knowledge, Merrick forces the pilots to change the course of action which saves a plane from crashing and killing hundreds of people. The mysterious man disappears before landing. Merrick is arrested by the FBI with the charge of plane hijacking attempt. Agent Baker is sure about the hijacking attempt while his younger assistant, Agent Stanton believes Merrick's story. However, Merrick's knowledge of the future disasters causes the changes in the future so the company Thrill Seekers sends two agents to the past to stop Merrick.