To put that another way, you need a Cessna certified cargo net
Not quite. The aircraft design requirements are published and locally approved tie down arrangements are (used to be) the usual way to go if you don't incline to the OEM style of things.
More than a few OWTs in this thread.
Motor vehicle restraint standards far exceed those prescribed as minimum for aircraft but, looking historically, that is reasonable .. the aircraft is presumed to crash on a "reasonable" surface (without excessive hard bits to run into .. ie the planned forced landing style of event) for which the prescribed restraint requirements are reasonably appropriate .. the motor vehicle really needs to look at head-ons and single vehicle run offs into significant obstacles. Hence, for aircraft, forward restraint of 9g (12g if one wants to be compatible with the older seating standards) against something approximately equivalent to 22g. While it hasn't made it into too many lighties, the current aircraft dynamic seat standards move a long way towards motor vehicle standards ..
Note that it is not at all difficult to design hardpoints to handle 20g+ in aircraft .. one just runs a structural strap over several frames or similar .. have done that in a number of cases in the past.
Keep in mind that somewhere in the order of 25-30g is the limit for the human body (aortas tear out .. stuff like that) .. hence we see 25G military seats.
As an aside, I am shortly to do my heavy vehicle endorsement and am studying up on the story .. it appears that truck load restraint is only 0.8g ? .. that doesn't impress me much at all ..
That is not to say that we design chaps stick to the minimum prescribed requirements .. in my (previous) ANR40/CAR35 life, I always went somewhat above as the weight penalty generally wasn't severe .. and, occasionally, I knew that I was going to be in front of said load.
Indeed, after one prang involving a Type which had my freight restraint system incorporated, the senior then BASI investigator gave me a call at home to let me know that the aircraft had disintegrated around my restraint system .. comforting and helps to keep one out of court discussions ...