I thought this was required by the FAA advisory circular governing parachute operations (https://www.faa.gov/documentLibrary/media/Advisory_Circular/... - PDF), but after just looking, I now think it was part of the supplemental type certificate (https://www.faa.gov/aircraft/air_cert/design_approvals/stc/) or 337 approval for the door modifications on the planes at the drop zone where I used to work.

Thus, it probably depends on the aircraft, and possibly the process by which the owner got FAA approval to modify the door.

I've been a skydiver for many years and as far as I know the FAA _does_ require the pilot to wear a bail out rig. Most skydiving pilots I know do wear them, but I have come across some pilots not wearing them in flight (even though their bail out rig was in the plane next to them).

Flight Chops is based in Canada, so anytime he's flying up here he'll fall under Transport Canada and Canadian Aviation Regulations (CARs). There are no legal requirements in Canada for pilots to wear parachutes.