CFR > Title 49 - Transportation > SUBTITLE B—Other Regulations Relating to Transportation > CHAPTER VIII—NATIONAL TRANSPORTATION SAFETY BOARD (Parts 800–851) > PART 821—RULES OF PRACTICE IN AIR SAFETY PROCEEDINGS > SUBPART B—General Rules Applicable to Petitions for Review, Appeals to the Board, and Appeals From Law Judges Initial Decisions and Appealable Orders (§821.6 to §821.21) > 821.13—Waivers.