This sounds like it's probably The 13th Hour (2009) by Richard Doetsch, although you may have a few details confused. The blurb for the book reads:
At 9pm on July 28, Nick Quinn is given an extraordinary opportunity, a chance to rewrite history and save his wife Mary's life. At 9pm, Nick is being held in jail, accused of Mary's murder. He saw her bloody corpse; he knows that she is dead. That's when a grey haired gentleman presents him with a talisman that allows him to go back in time, one hour at a time, for a total of twelve hours. With each hour that Nick journeys back in time, he finds more clues to the identity of Mary's real killer, but he also discovers that his actions in the past have unexpected repercussions on the future. All his good intentions of saving Mary's life may in fact lead to a far greater catastrophe than he could have imagined. If he hasn't set things right by the thirteenth hour, all will be lost.
It's possible that you confused his wife's death (by murder) with the plane crash, which a review on Goodreads notes:
The 13th Hour starts with Nick and Julia having a minor disagreement, before Julia sets off to work and Nick spends his day working from home. At almost 7 pm, Julia is murdered and Nick distraught. In the background of this story, a plane has crashed causing the death of all 212 passengers. With all the police at the crash site aiding with relief efforts, only 2 are spared for Julia's murder investigation. Nick is however, soon hauled into prison, with a murder charge hanging over his head, and the police's claim of finding his prints on a gun he had never seen, much less touched before, is threatening to keep him holed up in prison for long. At that point, walks in a European gentleman with a watch and a letter with certain instructions.
Another review notes the two hours back, one hour forward mechanic:
The concept here is that the protagonist travels back one hour before the hour he just lived through so a total of two hours back each time. He has to unravel a mystery that lead to the death of his wife and of course save her life.