touchback

Question
Team A kicks-off the ball to team B to begin the second half of a game.  No player from team B touches the ball.  They are allowing it to roll into the endzone for a touchback.  Player from team A runs down the field and gains possession of the ball when it is on the goal line. The whole ball is not behind the goal line.  Is this a touchback and team B has the ball on the twenty yard line or is this a touchdown for team A?
Thanks for your help!
Kevin

Answer
Kevin
If I understand your question Team A free Kick goes beyonf their restraining line/NZ and remains beyon, therefore they may recover the ball and they do so in the endzone [the ball breaks the plane of the endzone].  Therefore Team A is in possession of the live ball that becomes dead in Team B's endzone.  That is a touchdown.  A free kick or scrimmage kick is legally caught or recovered in the opponent抯 end zone is a touchdown.

When a free kick untouched by Team B touches the ground on or
behind Team B抯 goal line, the ball becomes dead and belongs to Team B.  It is a Touchback when a kick becomes dead by rule behind the defending team抯 goal line and the attacking team is responsible for the ball being there.

Now a free kick is a live loose ball and is not dead until kicked out of bounds or dead in player possession.  In your play Team A gains possession. It is dead immediately in team A's possession.  So when the player of the kicking team (Team A) catches or recovers any free kick that has crossed the neutral zone the ball becomes dead at the spot of recovery.  In your play the spot of recovery is in the opponent抯 end zone.  The front tip of the ball breaks the plane of the goalline thus it is a TouchDown.