I think the letter you refer to dates back to November 1990, in
response to query from AOPA. It may be available from them.

As I recall, the letter confirmed a previous interpretation of the
FARs for using one belt for two "individuals" provided the strength of
the belt is adequate for that use, but also adds that the practice may
not afford the same level of protection as separate belts would,
especially for children.

Hope this helps.

J


"Steve Foley" wrote in message ...
Someplace I saw a letter of approval stating that one seatbelt could be used
for two people. It was intended for use where there is a single seat belt
across a bench seat, but I've heard of people also justifying putting three
in the back with it.

I don't know where I saw it.