When do the noise aspects of a propeller and/or engine lead to a classification as major or STC?
When do the noise aspects of a propeller and/or engine lead to a classification as major or STC?
Answer
Any change that has an "appreciable effect" on the noise characteristics of an aircraft is referred to as an "acoustical change", and by definition is considered to be a major change. An "acoustical change" is defined as a change that increases the noise certification level by more than 0.1 dBA.
Last updated
02/12/2013