The iron and sulphur still behave like iron and sulphur in the mixture, but iron sulphide has different properties from both iron and sulphur. You can separate the iron from the mixture using a magnet but this does not work for iron sulphide. 1  Page.
Search for: An Airworthiness Directive (A.D.) is a directive issued when the FAA realizes that a perilous condition exists in a product (aircraft engine, airframe, appliance or propeller). They notify aircraft operators and owners of potentially unsafe conditions that need special inspections, alterations, or repairs.
A Proposed Rule by the Federal Aviation Administration on 08/05/2016 PDF - 3 pages. We propose to supersede Airworthiness Directive (AD) 2003-18- 06, for certain Airbus Model A319-131 and -132 airplanes; Model A320- 231, -232, and -233 airplanes; and Model A321-131 and -231 airplanes.