I had someone comment on the picture below because of safety concerns:
Let me elaborate a bit - the table saw's insert has been deliberately removed. (the big opening with the spinning saw blade is the area we're talking about) By no means is this a standard procedure. You should use the equipment's safety attachments and follow the manufacturer's instructions about proper use of the equipement you are handling.
In this operation, the sliding jig that is clamped to the saw table is being used to cut tapers on the ribs and the by-product of this cut is some long (10") wedge shaped pieces (~3/8" at the thick end) With the table saw's standard insert in place, these wedges get caught very easily and are thrown back at the operator - a big hazard. Without the plate in place, these pieces of scrap simply fall into the saw. This was done at the recommendation of the instructor based on his extensive experience with this process.
In terms of operator safety, you are well away from the blade. The operator's hand sits on the table in front of the opening to guide the ribs and the other hand holds the ribs well back from the table feeding them.
In the future, I'd like to try that operation with a sliding jig that has the handle placed a bit further back so that you are not reaching past the blade when you have to re-set the sliding jig. Also, I'd like to see if a zero-clearance insert would help or hurt the jamming and kick-back of those little wedges. Still, I think I'd want a full face shield, kevlar apron or maybe some armor.