StacksVerified U.S. regulatory reference

14 CFR §125.145

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Each firewall and shroud must—
  1. (a)Be so made that no hazardous quantity of air, fluids, or flame can pass from the engine compartment to other parts of the airplane;
  2. (b)Have all openings in the firewall or shroud sealed with close-fitting fireproof grommets, bushings, or firewall fittings;
  3. (c)Be made of fireproof material; and
  4. (d)Be protected against corrosion.