Hi Danalan, former skydiver checking in on this one.
No, there’s no law against bringing skydiving equipment as carryon luggage (dunno about post 9-11, if security gets fussy about a nailclipper I don’t think I’d try debating a parachute with them). I used to do it all the time in college.
A number of skydiving magazines and discussion boards ran articles on how to deal with any questions/objections that might be raised by security and the flight crew but there’s no regulation banning the stuff (at the time, as I said).
FWIW, Cecil ran an article sometime back about why you can’t open the doors inflight (gist of it is that the doors have to be pulled in a bit before swinging out of the way, and pressure inside the cabin of a few psi compared to outside means that you wouldn’t be able to do this without a chain hoist) which does away with the DB Cooper business. And unless you know exactly what you are doing, exiting at normal cruising altitudes and airspeeds will do some bad things to you…
Kinda off-topic as the OP was about rescue chutes for the entire plane (they are available for hanggliders and ultralights), not the individual passengers.
I do have a photo of an entire Cessna 182 along with passengers being lowered to earth under a single 28’ round canopy as a result of an interesting skydiving “incident”…