FAR 23.2325 — Fire Protection
FAR 23.2325 sets fire protection rules for Part 23 airplanes: self-extinguishing materials, extinguishers, cargo fire detection, and flammable fluid safeguards.
In Plain English
FAR 23.2325 establishes fire protection design standards for Part 23 (small) airplanes. The rule sorts requirements by airplane level (1–4, based on size and passenger capacity) and by where materials are located.
Key requirements:
- Self-extinguishing materials: electrical wire/cable insulation; inaccessible baggage and cargo compartment materials (levels 1–3); and cockpit, cabin, and baggage/cargo materials in level 4 airplanes.
- Flame-resistant materials: items in compartments accessible in flight (levels 1–3) and electrical equipment that could overheat from a fault or overload.
- Thermal/acoustic insulation in the fuselage cannot create a flame propagation hazard.
- Heat sources in baggage/cargo compartments must be shielded and insulated.
- Level 4 airplanes need cargo fire visibility or a detection and warning system, plus a way to extinguish or contain a fire.
- A fire extinguisher must be reachable by the seated pilot; levels 3 and 4 also require one accessible to passengers.
- Areas where flammable fluids or vapors could leak must be defined and protected against ignition.
- Combustion heaters must be protected from uncontained fire.
Why it matters: in-flight fire is one of the most time-critical emergencies. These design standards reduce ignition risk and give the crew tools and time to respond.
Regulation Text
14 CFR § 23.2325§ 23.2325 Fire protection.
(a) The following materials must be self-extinguishing—
(1) Insulation on electrical wire and electrical cable;
(2) For levels 1, 2, and 3 airplanes, materials in the baggage and cargo compartments inaccessible in flight; and
(3) For level 4 airplanes, materials in the cockpit, cabin, baggage, and cargo compartments.
(b) The following materials must be flame resistant—
(1) For levels 1, 2 and 3 airplanes, materials in each compartment accessible in flight; and
(2) Any equipment associated with any electrical cable installation and that would overheat in the event of circuit overload or fault.
(c) Thermal/acoustic materials in the fuselage, if installed, must not be a flame propagation hazard.
(d) Sources of heat within each baggage and cargo compartment that are capable of igniting adjacent objects must be shielded and insulated to prevent such ignition.
(e) For level 4 airplanes, each baggage and cargo compartment must—
(1) Be located where a fire would be visible to the pilots, or equipped with a fire detection system and warning system; and
(2) Be accessible for the manual extinguishing of a fire, have a built-in fire extinguishing system, or be constructed and sealed to contain any fire within the compartment.
(f) There must be a means to extinguish any fire in the cabin such that—
(1) The pilot, while seated, can easily access the fire extinguishing means; and
(2) For levels 3 and 4 airplanes, passengers have a fire extinguishing means available within the passenger compartment.
(g) Each area where flammable fluids or vapors might escape by leakage of a fluid system must—
(1) Be defined; and
(2) Have a means to minimize the probability of fluid and vapor ignition, and the resultant hazard, if ignition occurs.
(h) Combustion heater installations must be protected from uncontained fire.
Oral Exam Questions a DPE Might Ask
Q1What materials in a small airplane must be self-extinguishing under the certification rules?
Per FAR 23.2325(a), insulation on electrical wire and cable must be self-extinguishing, along with inaccessible baggage and cargo compartment materials in levels 1–3 airplanes, and cockpit, cabin, and baggage/cargo materials in level 4 airplanes.
Q2What are the fire extinguisher accessibility requirements in the cabin?
FAR 23.2325(f) requires a fire extinguishing means the pilot can easily access while seated, and for level 3 and 4 airplanes, an extinguishing means must also be available within the passenger compartment.
Q3How does FAR 23.2325 address baggage and cargo compartment fires in level 4 airplanes?
FAR 23.2325(e) requires each baggage/cargo compartment to either be visible to the pilots or equipped with a fire detection and warning system, and to be accessible for manual extinguishing, equipped with a built-in extinguishing system, or sealed to contain the fire.
Studying for a checkride?
Related Sections in Part 23