For example, the airframe rating has four subclasses (small composite construction, large composite, small all-metal and large all-metal) but in those ratings, which were drafted in 1962, the term composite refers to aircraft that have a mix of metal, wood and fabric in their construction and not to the modern definition of carbon fiber and resin. The new rating doesn't make a distinction between the size and construction of aircraft and effectively means that a certificate holder will be qualified to work on anything from a Piper Cub to a Boeing 787.

The FAA said its research showed that the maintenance capabilities didn't vary with the type of construction and that weight is no longer an accurate measure of the airplane's intended use or its complexity. The new ratings do away with horsepower limitations on reciprocating engines but they continue to distinguish between piston and turbines. The old "radio" rating ould be replaced with a more general "avionics" rating that would allow the certificate holder to work on a variety of ommunications, navigation and radar gear.

Source: avweb.com