NF rules, as NCAA is different. We had play #1 the other night so I’ll let you weed through it as we did. The others are related FC situations.

1. Scrimmage kick and legal FC signal. Ball takes a bounce, the receiver who signaled FC fields it and is immediately hit and tackled. What do you have? KCI, PF, or nothing?

2. Similar question but after the ball bounced the same receiver is coming up to field the ball when he is hit by a K player. Do you have KCI or not and why or why not?

3. The receiver who signaled FC cannot block til the kick ends, so what if he is just standing there as the ball bounces and a K player comes to block/hit him, can he defend himself and block back or would this be an illegal block after a FC signal?

My understanding (as a first year umpire) is:

#1 - nothing, as long as there was no KCI before the ball was grounded.

#2 - same, assuming by "hit" you mean either "blocked legally" or "tackled legally" (if the circumstances caused K to reasonably think he was a runner.)

#3 - "defend himself and block back": these are two different things. He cannot block, but I would think he could defend himself kind of like an umpire or runner does, using his hands to soften direct hits.

Where does it say in the rule book that the "protection" for the receiver who signaled ends when the ball is grounded? I know he cannot have a real "fair catch," but where does it say he loses his protection? This is for scenario number (2) that I listed.

Here are the NF rules regarding fair catch.

SECTION 5 FAIR CATCH
ART. 1 . . . Any receiver may signal for a fair catch while any legal kick is in flight. Any receiver who has given a valid or invalid fair-catch signal is prohibited from blocking until the kick has ended.
ART. 2 . . . It is a fair catch and the ball is dead if any receiver gives a valid fair-catch signal, as in Article 1, and he catches a free kick in or beyond the neutral zone to R's goal line, or a scrimmage kick beyond the neutral zone to R's goal line.

ART. 3 . . . Only the receiver who gives a valid signal is afforded protection. If, after a receiver signals, the catch is made by a teammate, it is not a fair catch but the ball becomes dead.
ART. 4 . . . The captain may choose to free kick or snap anywhere between the inbounds lines on the yard line through the spot of the catch when a fair catch is made or through the spot of interference, when a fair catch is awarded. These choices remain if a dead-ball foul occurs prior to the down, or a foul or an inadvertent whistle occurs during the down and the down is replayed.

ART. 5 . . . No receiver may advance the ball after a valid or invalid fair-catch signal has been given by any member of the receiving team.
ART. 6 . . . While any free kick is in flight in or beyond the neutral zone to the receiver's goal line or any scrimmage kick is in flight beyond the neutral zone to the receiver's goal line, K shall not touch the ball or R, unless blocked into the ball or R or to ward off a blocker, nor obstruct R's path to the ball. This prohibition applies even when no fair-catch signal is given, but it does not apply after a free kick has been touched by a receiver, or after a scrimmage kick has been touched by a receiver who was clearly beyond the neutral zone at the time of touching.

EXCEPTION: K may catch, touch, muff or bat a scrimmage kick in flight beyond the neutral zone if no player of R is in position to catch the ball.
ART. 7 . . . A receiver shall not give an invalid fair-catch signal.
ART. 8 . . . The runner shall not give an illegal fair-catch signal.
PENALTY: Blocking after giving a valid or invalid signal (Art. 1) – (S40) – 15 yards; delay of game (Art. 5) – (S21) – 5 yards; kick-catching interference (Art. 6) – (S33) – 15 yards. For interference, R may accept a 15-yard penalty from the previous spot and a replay of the down or choose to accept the penalty of an awarded fair catch at the spot of the foul. Invalid or illegal fair-catch signal (Arts. 7, 8) – (S32) – 5 yards.

MJT - you posted the answer yourself. Art 6 is where it tells you that K can't touch R (with exceptions) WHILE THE BALL IS IN FLIGHT. After it hits the ground, it is no longer in flight, and said protection no longer exists.

Good catch!