(b) Each forward-facing or aft-facing seat/restraint system in normal,
utility, or acrobatic category airplanes must consist of a seat, a safety
belt, and a shoulder harness, with a metal-to-metal latching device, that
are designed to provide the occupant protection provisions required in
§23.562.

Sounds like you need a safety belt for each seat and the word occupant is
singular.

--
Cy Galley
Safety Programs Editor
EAA Sport Pilot

"Rich S." wrote in message
...
"Gary Drescher" wrote in message
news:0pRSc.137433$eM2.73403@attbi_s51...

Is it actually unsafe to have two people sitting side-by-side and
sharing
a
seat belt, if their combined weight is within the belt's design limit?
(I
don't know; just asking.)

Piper did it for years.

Rich S.