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.
An aircraft maintenance technician refers to an individual who holds an Airframe and/or Powerplant (A&P) certificate which is issued by the Federal Aviation Administration (FAA). Just like pilots there are rules for certification and regulations which must be abided by for use of their license. An A&P technician inspects aircraft as well as performs, supervises and conducts preventive maintenance.