***Link*** :: [Aircraft Operations at Altitudes Above 25,000 Feet Mean Sea Level or Mach Numbers Greater Than .75](https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_61-107B_CHG_1_FAA.pdf) ***Description*** :: `= this.link` ***Author*** :: [[FAA]] #### Key Quotes * #source #advisory-circular #todo :: add key quotes