This is an informational post for all of you who are operating the much beloved Brittain autopilot systems. The latex vacuum tubing (Brittain P/N 116-010-003) utilized behind the panel of all aircraft equiped with Brittain control systems seems to have a service life of about a 5 to 7 year at best. I replaced mine in 2010 and again this year at annual.  I bring it up because merely looking at the tubing is not adequate to determine it's condition. I know that in the past, deteriorating tubing ha