A young, cocky walking encyclopedia must travel back in time with his two newly met friends from differing social standards to stop evil forces plotting to take down their transatlantic flight.

What DPG and Richiev said.
Also how does being a cocky walking encyclopedia either help or hinder the main character's efforts?

The character description should either explain how the main character will have an obstacle he or she must overcome in their inner journey before achieving their outer goal, or provide them with the means to successfully achieve their objective in the plot. Currently the main character description doesn't appear to do either.

What's the inciting incident?? That is, how does he come to know that there are evil forces out to sabotage the plane?on which he is traveling?

And what's the plot gimmick, the means by which he is able travel back in time?

And if he's a walking encyclopedia, why doesn't he have the smarts and know-It-all to stop the evil forces in the present, while he's on the plane?? What does he lack in the present that he can only acquire by going back to the non-future?

What's the inciting incident?? That is, how does he come to know that there are evil forces out to sabotage the plane?on which he is traveling?

And what's the plot gimmick, the means by which he is able travel back in time?

And if he's a walking encyclopedia, why doesn't he have the smarts and know-It-all to stop the evil forces in the present, while he's on the plane?? What does he lack in the present that he can only acquire by going back to the non-future?