Once upon a time they would have had to; but not a
Post# of 41413
(1) initial introduction of a type and model of airplane into passenger-carrying
operation,
(2) an increase in passenger seating capacity of five percent or greater, or
(3) a major change in the cabin interior that would affect emergency evacuation.
http://www.faa.gov/documentlibrary/media/advi...803-1a.pdf