No cause for alarm. Apparently itīs only a couple of the 90īs that are affected. And apparently itīs just a matter of the autopilot and the trim switch not talking to each other properly. The porpoising can easily be remedied by disconnecting the a/p, make a slight trim adjustment manually, then reconnect the a/p. Problem is the boys up front donīt notice it nearly as much as the pax in the back. So should this happen to you again, ask a hostie to tell the skipper that youīre getting seasick back there and please trim the #$% &%$# plane.