The FAA issued a request for comment on proposed airworthiness standards for certification of the Bell/Agusta BA609–“a multi-turbine-engine powered-lift category, tiltrotor-class aircraft”–under FAR 21.17(b), which specifies applicable regulations for special classes of aircraft for which airworthiness standards do not yet exist. According to the newly released BA609 draft certification basis document, “The tiltrotor rules provide proposed airworthiness standards not covered in Parts 23, 25 and 29.” The FAA procedure establishing appropriate airworthiness standards includes reviewing and possibly revising the application proposal, publication of the submittal in the Federal Register for public review and comments and addressing the comments. The deadline for comments is January 25.