The Raisbeck system is modelled here by N214F:
Photo © Eddy Gual - Aviation Photography Of Miami
Some Pan Am B727-200s were previously fitted with the DuganAir Technologies "Quietwing" system, like N365PA seen here:
Photo © Peter O. Johnson
The obvious question now is whether Pan Am has decided to ditch the DuganAir system due to a desire for standardization, or because the system has proved to be inadequate and/or problematic in service.
Does anyone have any insights on this move by Pan Am?