This may be the very most difficult play to officiate in all of football. Even tougher than targeting. The speed with which everything is happening, and the number of relevant rules is staggering. Even the most talented and skilled officials struggle with onside kicks. There is now way - NO WAY - that a single official can rule on all of this. With "six in the box," you stand a chance of piecing together the critical elements:
-Firstly, the B and U need to rule on offside by the kicking team. Happens frequently.
-Secondly, the S/F needs to know who touches the ball first and where. Not always easy, but generally not too big of a problem. If he gets that, most of the battle is won.
-Thirdly, the H/L (maybe the C, if you have one) needs to rule on blocking by Team A. This is the most difficult thing, because he has to know where is the ball when contact is made, and if the ball has been touched by B.
It is very important that each official takes his assignment, and doesn't try to make a total ruling by himself. Then, everybody has to get together, take as much time as needed, and report what they know, and piece together a ruling.
For crews of five: "Good luck; we're all counting on you."