CFR › Title 14 › Part 125 › §125.15114 CFR §125.151Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)Designated fire zones must be protected from fire by compliance with §§ 125.153 through 125.159.(b)Designated fire zones are—(1)Engine accessory sections;(2)Installations where no isolation is provided between the engine and accessory compartment; and(3)Areas that contain auxiliary power units, fuel-burning heaters, and other combustion equipment.