AC 120-80B

editorial update

Advisory circular · Firefighting of General and High-Energy In-Flight Fires

Approved
March 21, 2025
Last reviewed
March 21, 2025
This change
Editorial update to AC 120-80B.
Cancels
AC120-80B
Family
AC 120-80 · 4 versions
Revision
B
14 CFR parts
25, 91, 121, 135

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed June 25, 2026.

U.

S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Firefighting of General and High-Energy In-Flight Fires Date: 3/16/23 AC No: 120-80B Initiated by: AFS-200 Change:

1 PURPOSE OF THIS ADVISORY CIRCULAR (AC). This AC provides information on the hazards and risks of in-flight fires on transport category aircraft. The information includes recommended crewmember procedures and training for combating general and high-energy fires (HEF) caused by lithium batteries. This AC is applicable to operators conducting operations under Title 14 of the Code of Federal Regulations (14 CFR) parts 91, 91 subpart K (part 91K), 121, 125, and 135. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way, and the document is intended only to provide information to the public regarding existing requirements under the law or agency policies.

1.1 G eneral. This AC addresses the following:

1. The importance of flightcrew member initial and recurrent hands-on training, including:

• The use of operable oxygen mask/goggle sets, the use of the regulator’s emergency selector, and the venting of smoke goggles.

• Aircraft-specific training on establishing and maintaining internal flight deck communications when flightcrew members don oxygen masks.

2. The importance of flightcrew members stowing their oxygen masks set to 100 percent.

3. Guidance for operators’ smoke, fire, or fumes checklists to include, as the first step, that flightcrew members don their oxygen masks and verify that the regulator is set to 100 percent.

4. Guidance for operators on addressing the unique characteristics of lithium battery fires through procedures and training.

5. The dangers of in-flight fires with particular emphasis on hidden fires that may not be visible or easily accessed by the flight or cabin crewmembers. This AC discusses the importance of recognizing and quickly assessing the conditions that may be associated with hidden fires and the importance of taking immediate action to gain access to fires that are located behind interior panels.

6. Guidance on how to deal with in-flight fires by emphasizing the importance of flight and cabin crewmembers taking immediate and aggressive action in response to signs of an in-flight fire while stressing the effectiveness of halon extinguishing agents.

7. The importance of appropriate crewmember training in dealing with hidden fires, the effective application of fire extinguishing agents behind interior panels, and the urgency of the crew’s action in dealing with such fires.

8. Guidance that complements previously developed guidance for crewmembers concerning the proper use of cabin fire extinguishers (the current edition of AC 20-42, Hand Fire Extinguishers for Use in Aircraft, and National Fire Protection Association (NFPA) 408, Standard for Aircraft Hand Portable Fire Extinguishers) and the most effective means of extinguishing fires that are readily accessible.

9. Information from research conducted by the Federal Aviation Administration (FAA) William J. Hughes Technical Center (WJHTC). As additional information becomes available, it will be published in future revisions to this AC.

10. Information on and the use of fire containment kits/bags designed to contain lithium battery fires.

11. Guidance for crewmembers faced with a portable electronic device (PED) powered by a lithium battery that is overheating, expanding, smoking, or burning.

12. Identifies procedures that incorporate risk mitigation guidance from the International Air Transport Association (IATA), International Civil Aviation Organization (ICAO), and civil aviation authorities (CAA).

2 AUDIENCE. Air carriers, Directors of Operations (DO), Directors of Maintenance (DOM), Directors of Safety (DOS), Chief Pilots, Chief Inspectors, directors of in-flight/cabin safety training, training center curriculum designers, and others involved in the development of crewmember training programs as well as crewmembers and others involved in flight operations under part 121 should be familiar with the contents of this AC. This AC may also be valuable to operators associated with operations conducted under parts 91, 125, and 135.

3 WHERE YOU CAN FIND THIS AC. You can find this AC on the FAA’s website at https://www.faa.gov/regulations_policies/advisory_circulars and the Dynamic Regulatory System (DRS) at https://drs.faa.gov.

4 WHAT THIS AC CANCELS. AC 120-80A, In-Flight Fires, dated December 22, 2014, is canceled.

5 USING THIS AC. When tailored to specific aircraft and operators’ procedures, the suggested guidelines presented in this AC provide a good framework for mitigating the risk of and combating general and high-energy in-flight fires. However, approved aircraft manufacturer procedures should take precedence over the information presented in this AC. The importance of crewmembers taking immediate and aggressive action to locate the source, gain access, and effectively apply extinguishing agents to hidden fires cannot be overstressed. The multitude of cabin configurations that are currently in use throughout the industry complicates this task. For this reason, there is no single formula for fighting and extinguishing in-flight fires.

3 6 RELATED REGULATIONS (14 CFR).

• Part 25, § 25.851.

• Part 91, § 91.513.

• Part 121, §§ 121.215, 121.221, 121.273, 121.275, 121.308, 121.309, 121.337, and 121.703.

• Part 135, §§ 135.170, 135.331, and 135.415.

7 DEFINITIONS.

7.1 Aggressively Pursue. Aggressively pursuing a fire means taking immediate action to determine the source of hot spots, smoke, and/or flames. The crew should quickly evaluate the situation, gain access to the fire, and attack the fire using all available resources, which may include deadheading crewmembers or able-bodied persons (ABP).

7.2 Aqueous-Based Extinguishing Agents. Aqueous agents provide a heat absorption (cooling) effect on the burning material to extinguish the fire. Aqueous film-forming foam (AFFF) and film-forming fluoroprotein (FFFP) fire extinguishers are rated for use on Class A and B fires. Aqueous-based extinguishing agents sprayed on the PED to cool the cells in the battery have been demonstrated to be effective to prevent the propagation of TR.

7.3 Cheek Area. The area just below the floor, outboard of the cargo compartment areas. In narrow and wide body aircraft, this area houses wire bundles, hydraulic lines, and other electrical components (see Appendix C, Typical Wide Body C ross-Section).

7.4 Circuit Breaker. Circuit breakers are designed to open an electrical circuit automatically at a predetermined overload of current.

7.5 Electrical Arc. An electrical breakdown of a gas that produces a prolonged electrical discharge.

7.6 Halon. A liquefied gas that extinguishes fires by chemically interrupting a fire’s combustion chain reaction rather than physically smothering it. This characteristic is one of the main reasons that halon extinguishers are effective when the exact source of the fire cannot be positively determined. Halon fire extinguishing agents that have been approved for use in aircraft include Halon 1211, Halon 1301, and a combination of both (Halon 1211/1301). Both Halon 1211 and Halon 1301 are typified as “clean agents,” which leave no agent residue after discharge. Approved halon-type extinguishers are three times as effective as carbon dioxide (CO2) extinguishers with the same weight of extinguishing agent.

7.6.1 H alon 1211. The chemical name is bromochlorodifluoromethane. Halon 1211 is a multipurpose, Class A, B, and C-rated agent that is effective against fires fueled by flammable liquids (see Appendix E, Information on Using Hand Fire Extinguishers, f or definitions of the classes of fires). Halon 1211 fire extinguishers discharge in an

4 85 percent liquid stream, giving the agent a range of 9 to 15 feet, which offers a significant advantage in fighting fires in large aircraft cabins.

7.6.2 H alon 1301. The chemical name is bromotrifluoromethane. Halon 1301 has Class A, B, and C capability in total flooding systems;1 however, Halon 1301 has limited Class A capability when used in portable fire extinguishers. The useable range of a Halon 1301 extinguisher is slightly less than that of a Halon 1211 extinguisher.

1 Total flooding systems are generally designed to fully discharge their contents upon being activated.

7.7 Halotron BrX. The chemical name is 2-bromo-3,3,3-triflouro-1-propene and commonly referred to as 2-BTP. Halotron BrX has been approved for use in aircraft as noted in AC 20-42. Halotron BrX is a multipurpose, Class A, B, and C-rated clean agent that has both a low global warming potential and a near zero ozone depletion potential while being highly effective at fighting fires fueled by liquid combustibles. It extinguishes a fire through the removal of heat as a result of the chemical reaction taking place between the agent and the fire.

7.8 Hidden Fires. “Hidden” fires are not readily accessible, may be difficult to locate, and are more challenging to extinguish. Some examples of hidden fires would be fires behind sidewall paneling or in overhead areas.

7.9 High-Energy Fire (HEF). A fire involving a battery or other energy storage device that has components or materials with the potential to release a significant amount of additional energy that would further fuel the fire. This results in a heat release and rate of heat release that is higher than a typical Class A fire, can more easily harm nearby individuals, and can be characterized as relatively unpredictable.

7.10 Knock Down. To reduce the flame or heat on the more vigorously burning part of a fire edge.

7.11 Lithium Battery. Batteries commonly used to power consumer PEDs, including those used to power authorized Electronic Flight Bags (EFB) supplied by the operator. There are two types of lithium batteries: lithium metal (typically nonrechargeable) and lithium ion (rechargeable).

7.12 Overhead Area. The area within the aircraft fuselage located above the ceiling panels.

This area ranges in volume depending on the aircraft type. In a narrow body transport aircraft, this area may be only several inches high running the length of the fuselage.

However, in wide body aircraft, this volume is much larger and may range in height from 2 to 4 feet or more. A typical overhead area contains components of the aircraft’s entertainment system, numerous wiring bundles, control surface cables, portions of the air conditioning system, the passenger emergency oxygen system, and other systems (see Appendix C).

7.13 Recirculation Fan. These units are typically located in the overhead area and recirculate air in this space to prevent elevated temperatures and remove stagnant air.

7.14 Return Air Grills. Vents located along the baseboard area of each sidewall of the passenger cabin. Most transport category aircraft have air conditioning systems that supply conditioned air near the cabin ceiling. This air flows in a top-to-bottom direction, exiting through the return grills, and eventually out the fuselage via the outflow valve(s).

7.15 Smoldering Fire. Combustion without a visible flame and a slow combustion rate are characteristics of a smoldering fire. A smoldering fire left unattended or an incompletely extinguished fire can ignite and grow into a larger, uncontrollable fire in a short time period.

7.16 Suppressed Fire. A partially extinguished fire that may or may not have visible flames.

A suppressed fire, if not extinguished, may reestablish itself and grow into a larger, uncontrollable fire in a short time period.

7.17 Thermal Runaway (TR). Rapid self-sustained heating of a battery cell driven by a chemical reaction of the materials within the cell where energy is released in the form of light or heat. TR is generally evidenced by a sharp increase in temperature and pressure and a drop in cell voltage.

7.18 Water Extinguisher. An extinguisher containing water that is designed with a CO2 cylinder in the handle to pressurize the water inside so it can be propelled from the extinguisher.

8 RESOURCES (current editions).

8.1 FAA Documents:

• AC 20-42, Hand Fire Extinguishers for Use in Aircraft.

• AC 25-9, Smoke Detection, Penetration, and Evacuation Tests and Related Flight Manual Emergency Procedures.

• AC 25-16, Electrical Fault and Fire Prevention and Protection.

• AC 120-48, Communication and Coordination Between Flightcrew Members and Flight Attendants.

• AC 120-76, Authorization for Use of Electronic Flight Bags.

• Safety Alerts for Operators (SAFO) 09013, Fighting Fires Caused by Lithium Type Batteries in Portable Electronic Devices.

• FAA Order 8900.1, Flight Standards Information Management System, chapters and sections that address cabin safety issues and emergency procedures.

8.2 Related Research Material:

• A Benefit Analysis for Enhanced Protection From Fires in Hidden Areas on Transport Aircraft, DOT/FAA/AR-02/50, CAA Paper 2002/01, report prepared by R G W Cherry and Associates.

• In-Flight Aircraft Seat Fire Extinguishing Tests (Cabin Hazard Measurements), DOT/FAA/CT-82/111, Hill, R.G., and Speitel, L., December 1982.

• Effectiveness of Flight Attendants Attempting to Extinguish Fires in an Accessible Cargo Compartment, DOT/FAA/AR-TN99/29, Blake, D., April 1999.

• Halon Extinguishment of Small Aircraft Instrument Panel Fires, DOT/FAA/CT-86/26, Slusher, G.R., Wright, J.A., and Speitel, L.C., December 1986.

• ICAO Doc 9284, Technical Instructions for the Safe Transport of Dangerous Goods by Air.

• IATA Dangerous Goods Regulations (DGR).

• IATA Lithium Battery Risk Assessment Guidance for Operators, “Cargo Operations” and “Passenger Operations” sections.

• IATA Cabin Operations Safety Best Practices Guide.

• NFPA 408, Standard for Aircraft Hand Portable Fire Extinguishers.

• NFPA 1971, Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting.

9 SUBTLE CAUSES OF IN-FLIGHT FIRES.

9.1 Wiring Failures. A majority of hidden in-flight fires are the result of electrical arcs along wire bundles. In most cases, the electrical arc acts as the initiating event, igniting other surrounding materials. The surface of insulation materials is often a conveyer of these initiating events, as contamination from spillage, accumulated dirt/dust, lubrication, or corrosion inhibitors on these surfaces can promote flame spread (uncontaminated insulation materials are generally very fire resistant). In other instances, the resetting of a tripped circuit breaker can overheat wiring, ultimately leading to failure and arcing, causing the same chain of events.

9.2 Electronically Adjustable Seats. Operator procedures should address crew communication, safe operating instructions, and precautions to prevent PEDs from being crushed. Event reports have identified overheating and battery damage as hazards associated with extreme pressure or crushing a lithium battery-powered PED in an electronically adjustable seat. Crew reports indicate that passenger seat mechanisms have damaged PEDs that have slipped beneath the passenger seat.

9.3 Electrical Component Failures. Electrical motors can overheat, bind, fail, and possibly ignite surrounding materials. An accumulation of contaminants in the immediate area exacerbates the spread of fire in these instances.

9.4 Lightning Strikes. Although very infrequent, there have been instances in which a lightning strike has initiated a fire. In these instances, faulty or contaminated insulation material contributed to the fire.

9.5 Bleed Air Leaks. Aircraft with systems that use air from the engine (bleed air) depend on a series of pneumatic lines to deliver the air supply. A failure of any of these supply lines, if left unchecked, can cause high temperatures in the surrounding area and damage to the aircraft’s equipment, wiring, and associated components. High-temperature bleed air leaks have caused in-flight fires and structural damage.

9.6 Faulty Circuit Protection. A malfunctioning circuit breaker that does not open (trip) when it detects an abnormally high current draw may cause the affected unit or associated wiring to overheat and ignite.

9.7 Lithium-Ion Batteries. Lithium-ion batteries are rechargeable batteries that are being installed in newer-design aircraft to power multiple systems or equipment, and these batteries are capable of overheating. This can lead to a process called TR, which can cause the sudden release of the contents of the battery as a flaming jet, heavy smoke, or unburned hydrocarbons. In some cases, the battery can explode or rocket. Once one cell in a battery pack goes into TR, it produces enough heat to cause adjacent cells to go into TR. The resulting fire can flare repeatedly as each cell ruptures and releases its contents.

10 INDICATIONS OF HIDDEN FIRES.

10.1 Abnormal Operation or Disassociated Component Failures. Failure or uncommanded operation of an aircraft component may indicate a developing fire. Electrical connections and the components themselves may have had damage from a fire in the area of the component or at any point along its power supply line. For this reason, cabin crewmembers should report all failures of electrical items to the flightcrew members in accordance with company policy and procedures.

10.2 Circuit Breakers. Circuit breaker(s) tripping, especially multiple breakers, such as entertainment systems or coffee makers, may be an indication of damage occurring in a hidden area common to the affected components.

10.3 Hot Spots. Hot spots on the floor, sidewall, ceiling, or other panels should be immediately investigated.

10.4 Fumes. This may be one of the first indications of an impending fire. Never ignore a strange odor; crewmembers need to identify its source as soon as possible.

10.5 Visual Sighting of Smoke. Smoke coming from vents or seams between interior panels, especially from the ceiling area, is an indicator of a problem, and crewmembers should take immediate action to determine the source.

8 11 RESOURCES AVAILABLE FOR FIGHTING IN-FLIGHT FIRES. The available resources depend on the aircraft’s specific cabin configuration, which may vary within types. Therefore, crewmembers should include this subject in crew briefings as suggested in AC 120-48.

11.1 Firefighting Tools. In addition to aircraft emergency equipment required under 14 CFR parts, crewmembers should also consider those items not normally thought of as firefighting aids. For example, the crewmember may pour nonalcoholic liquid, such as coffee, soda, juice, or water, onto a fire.2 When extinguishing a suspected electronic device fire, douse the device with water, an aqueous-based extinguishing agent, or other nonalcoholic liquids to cool the device and prevent additional battery cells from reaching TR. For example, crewmembers have used a carbonated beverage as a fire extinguisher by shaking up the can or bottle, opening the top, and spraying the contents at the base of the fire. Any of these suggestions may prove to be effective as possible firefighting methods. These examples are not meant to be all-inclusive, and crewmembers should consider what other items might be useful.

2 As mentioned below in paragraph 12.1.1, crewmembers should not use water if the fire is of aircraft electrical s ystem origin.

11.2 C ontainment Products Used for Firefighting. There are various firefighting kits and containment products marketed for in-flight use. The FAA does not prohibit the use of the various commercially manufactured containment products. The FAA-sponsored High-Energy Firefighting Training Enhancement (HEFTE) working group presented questions on the effectiveness of fire containment devices to FAA researchers.3 The researchers emphasized the dangers associated with picking up the PED while the device is in an unstable condition (i.e., the fire is still actively burning, the device is unstable, or the device is hot). A fire in one cell of a battery may not have propagated to other cells, but if the device is hot, the potential for propagation exists. Therefore, the device should be cooled before it is moved to a containment device.4 3 Refer to FAA Air Carrier Training Aviation Rulemaking Committee (ACT ARC) Recommendation 18-5, Guidance on Fighting High-En ergy Fires (2018).

4 Id. at 32 (citing ICAO Doc 9481, Emergency Response Guidance for Aircraft Incidents Involving Dangerous Goods, 3.3.1, Battery/Portable Electronic Device (PED) Fire/Smoke (2 021–2022)).

11.2.1 O n December 10, 2020, the Underwriters Laboratories (UL) announced a new standard for fire containment bags: ANSI/CAN/UL 5800, the Standard for Safety for Battery Fire Containment Products. The new standard includes testing and certification and should reduce the risk of in-flight TR events in the future.

11.2.1.1 ANSI/CAN/UL 5800 was developed by UL with input from a Standards Technical Panel made up of international representatives from airlines, shipping companies, and other aviation-related organizations along with government bodies (including the FAA) and containment product developers.

11.2.1.2 The standard provides test methodology and performance criteria and sets construction, testing, marking, instruction, and packaging requirements. It has been nationally accepted by the American National Standards Institute (ANSI)

9 and the Standards Council of Canada (SCC), increasing consistency in the safety of battery containment products across both countries and jurisdictions.

11.2.2 Manufacturers may have stated in their advertisement and marketing videos that their products are “FAA certified,” “successfully tested by the FAA,” or “meet FAA standards.” However, the Fire Safety Branch of the FAA WJHTC and the Aircraft Certification Service (AIR) emphasize that no FAA test standards exist for these containment products nor does the FAA have a mechanism in place for the approval of these products. The FAA has no objection to the use of the various commercially manufactured containment products.

11.2.3 With the advent of these commercially marketed containment products, operators may have amended or may be considering amending their firefighting procedures and training programs to align with procedures suggested by the manufacturers of these containment products. Through continuous research and evaluation by the Fire Safety Branch of the FAA WJHTC and the Transport Airplane Directorate (TAD), the FAA finds the procedures as set forth in this AC provide the best means to address fires or overheating caused by lithium batteries.

11.3 Firefighting Gloves. Federal regulations do not require firefighting gloves. However, many carriers have used their Safety Risk Management (SRM) process to justify having these protective tools on board. Operators should consider proper fit, dexterity, and protection, as stated by the NFPA,5 when considering firefighting gloves. Firefighting glove ratings are based on the Thermal Performance Protective (TPP) scale. Firefighting gloves should have a TPP of at least 35.0 with a second-degree burn time of no less than

10.0 seconds and a pain time of no less than 6.0 seconds to comply with NFPA 1971, Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting.

5 NFPA 1971 provides minimum levels of protection for professional firefighters.

11.4 Able-Bodied Passengers. Crewmembers should consider deadheading crewmembers and able-bodied passengers as additional resources when combating a fire. The ability to enlist the help of qualified individuals, especially on a single flight attendant (F/A) operation, might be very valuable in combating a fire and communicating with the flightcrew members. Regardless of the type of operation, crewmembers should consider using all available resources when faced with an in-flight fire.

12 FIRE EXTINGUISHERS.

12.1 Type of Fire Extinguisher to Use. Immediate and aggressive action when confronted with a potential fire is much more important than delaying while you attempt to classify a particular fire. As a general rule, halon fire extinguishers are the best choice since halon is classified as a multipurpose (Class A, B, and C fires) agent.

12.1.1 Initial Focus. Upon di scovering a fire, the initial focus should be on aggressively extinguishing the fire with a readily available extinguisher (which will likely be halon);

however, crewmembers should not use water if the fire is of aircraft electrical system origin. Generally, consider using the first available extinguisher rather than delaying firefighting efforts while locating a particular extinguishing agent for a Class A, B, or C fire. After initially suppressing the fire or exhausting the first fire extinguisher, use the preferred extinguishing agent for the class of fire to maintain control or extinguish the fire (see Appendix E).

12.1.2 Exceptions. Ther e are a few exceptions to this general guidance. Crewmembers should not discharge a water fire extinguisher directly into a circuit breaker panel or an electrical outlet. Water should also not used to combat a liquid fire (e.g., grease or fuel) pooled or collected on a nonporous surface. The use of a water extinguisher on a fire fueled by flammable liquids is acceptable if the surface has absorbed the liquid, such as gasoline poured on a seat or other absorbent material.

12.2 Handhel d Fire Extinguishers Should Be Held Upright. Handheld fire extinguishers are designed for use in the upright position. Most extinguishers have been designed with a center siphon tube that extends to the bottom of the canister. Placing a fire extinguisher on its side or upside down prevents the agent from flowing through the tubing, which has been designed to collect the agent from the bottom of the canister. Laying the extinguisher on its side or turning it upside down to aim at the ceiling may limit the amount of extinguishing agent that is available to be discharged, thereby reducing the extinguisher’s firefighting capacity. Consequently, fire extinguishers equipped with flexible discharge hoses and nozzles are better suited to handle fires that may necessitate discharging the agent in an upward direction or in any other situation requiring flexibility.

The installation and use of fire extinguishers with flexible hoses is highly desirable for these reasons.

13 HALON EXPOSURE. Various publications, including AC 20-42, caution against exposure to “high levels” of halon in confined spaces, citing the possibility of dizziness, impaired coordination, and reduced mental sharpness. AC 20-42 also provides guidelines that describe what is meant by the term “high level” and further states that these levels should not be exceeded in ventilated or nonventilated passenger compartments on aircraft. However, studies have shown that discharging all of the handheld halon extinguishers required by regulation6 in the passenger cabin of an aircraft will not exceed the maximum concentration levels of halon vapor specified in AC 20-42 or NFPA 408 guidelines.

6 Hand fire extinguishers are required under 14 CFR § 25.851(a)(l); part

13.1 Nat ional Transportation Safety Board (NTSB) Recommendation. The NTSB has expressed concern that crewmember training programs have overemphasized the risks of exceeding the maximum recommended levels of halon gas, especially when compared to the risks of an in-flight fire. The NTSB emphasizes “…that the potential harmful effects on passengers and crew [of Halon] are negligible compared to the safety benefits

29, §§ 29.851(a)(l) and 29.853(e) and (f);

§ 91.513(c); part 119, § 119.25; § 121.309(c); and § 135.155.

11 achieved by fighting in-flight fires aggressively.”7 7 NTSB Safety Recommendation Letter, dated January 4, 2002.

The toxic effects of a typical aircraft seat fire, for example, far outweigh the potential toxic effects of discharging a halon fire extinguisher.

14 QUESTIONS FOR OPERATORS TO CONSIDER WHEN DEVELOPING PROCEDURES AND TRAINING.

14.1 How Critical Are Small In-Flight Fires? In-flight fires left unattended, particularly those that are not readily accessible, may lead to catastrophic failure and result in the complete loss of airplanes. Fire tests conducted by various regulatory authorities have shown that fires allowed to spread into the aircraft’s overhead area may become uncontrollable in as few as 8 to 10 minutes. Studies have also shown that a flightcrew member may have as few as 15 to 20 minutes to get an aircraft on the ground if the crew allows a hidden fire to progress without any intervention. Appendix D, Time to Becoming Nonsurvivable, provides various illustrations of the time from the first indication to the crew of the presence of a hidden fire until it becomes catastrophically uncontrollable. These studies and other experiences indicate that flightcrew members should begin planning for an emergency landing as soon as possible after the first indication of fire. Delaying the aircraft’s descent by only a couple of minutes might make the difference between a successful landing and evacuation and the complete loss of an aircraft and its occupants.

14.2 What Should Crewmembers Do If They Suspect a Hidden Fire? In accordance with company policies and procedures, coordinate with other crewmembers, as applicable, and take immediate and aggressive action to locate and extinguish the fire.

14.3 Is It Necessary to Locate the Exact Source of a Fire Before Applying Extinguishing Agent? It is not necessary in all circumstances. There have been several incidents where fires have been extinguished with a stream of halon by discharging the fire extinguisher into the air return grills (for fires beneath floor) or into the overhead area. Some aircraft

(e.g., ATR-72) have cargo compartments that are locked by ground personnel prior to door closure and unlocked at destination. F/As do not have access to these compartments;

however, there is an opening where an F/A can discharge a fire-extinguishing agent if a fire occurs in flight.

14.4 Should Holes Be Cut or Punched in an Aircraft Cabin Wall, Ceiling, or Floor Panel in Order to Gain Access to a Fire? If this is the only way to gain access to the fire, yes.

In this situation, crewmembers should weigh the risk of damaging equipment behind the paneling and the possibility of creating a bigger problem against the catastrophic potential of in-flight fires left unattended. F/As should quickly and accurately describe to a flightcrew member the location where the crash axe will be used so a flightcrew member can determine the risk involved.

14.5 What Resources Can Be Used to Access Hidden Fires? Consider all available resources to access a hidden fire. Items found in carry-on baggage might be useful, nontraditional resources, such as a shoehorn, knitting or crocheting needles, walking canes, and fairly rigid items that could pry apart paneling. One of the best defenses is to be familiar with the interior configuration of the specific aircraft. This familiarity provides clues as to what tools would be most effective when trying to gain access to hidden areas of the aircraft. For example:

1. Some aircraft are equipped with a manual release tool that is designed to open the oxygen compartments. Crewmembers may use this device to separate or pull apart sidewall panels to permit access to a hidden fire.

2. Some aircraft have cabin ceiling speaker covers that are removable by simply snapping them out of their fixture. The removal of these covers provides access to the overhead area in the immediate area of the speaker fixture.

3. Equipment located in raft survival kits that are not an integral part of a survival raft may be useful for gaining access to hidden fires.

4. Galley equipment such as casserole or ice tongs, metal cutlery, or similar items may be useful in separating interior panels.

5. One of the most important elements in successfully combating an in-flight fire is an individual’s own resourcefulness and determination in accessing hidden areas within the aircraft.

14.6 What Is the Best Way to Locate Hot Spots on a Door or Interior Panel Before Attempting to Open or Remove It? While there is no single best method, using the back of one’s hand (instead of fingers or palms) is recommended because:

14.6.1 The skin on the back of the hand is more sensitive to temperature variations than palms or fingertips. Using the back of one’s hand allows for more sensitivity to temperature fluctuations while running one’s hand along a panel, making it easier to locate hot spots on the panel.

14.6.2 Using the back of the hand protects one’s palm and fingers from injuries. For example, there is a possibility of being burned if one was to grasp a hot door handle (e.g., lavatory door) using the palm and fingers of the hand. A burned hand would make firefighting activities more difficult and could cause a delay in extinguishing the fire and conducting an evacuation of passengers.

14.7 What Should Crewmembers Do If They Suspect a Fire in a Lavatory?

14.7.1 If you suspect a fire in a lavatory, immediately notify another crewmember, get the closest fire extinguisher, and check the door for heat.

14.7.2 Cautiously and slowly open the lavatory door. Try to locate the source of the fire and discharge the fire extinguisher at the base of the fire. If you cannot clearly identify the source of the fire, aggressively attempt to locate the cause of the smoke and extinguish the fire. If the base of the flames or the source of the fire is not readily identifiable,