13 crewmembers should not discharge the agent with the intent of suffocating the smoke.
There are some lavatory doors with air vent grills. (When developing fire in a lavatory procedures, the operator should compare their procedures to the aircraft manufacturers’ procedure recommendations for this unique type of lavatory door design feature as part of their SRM process.) It is possible that the fire-extinguishing agent could be discharged through the air vent grill, or, in some cases, it may be advantageous to cover the air vent grill to prevent smoke and fumes from escaping into the cabin. All efforts should be used to fight a fire and not waste valuable extinguishing agent on smoke.
14.7.3 It is critically important to protect oneself from the effects of smoke and fumes while attempting to fight a fire. Crewmembers should not enter an enclosed area or begin to battle a fire that is generating heavy smoke without first donning Protective Breathing Equipment (PBE). A small fire can quickly grow to be large and uncontrollable. Time is critical when combating an in-flight fire; every available resource to locate and extinguish it should be used. Research has shown that a fire left uncontained can destroy an aircraft in as few as 20 minutes, and a smoke-filled cabin can be completely consumed by fire in as few as 6 to 10 minutes.
14.8 What Are The Recommended Procedures for Fighting an HEF? The public’s use of PEDs is increasing. According to the FAA Air Traffic Organization (ATO), part 121 operators transport approximately 2.5 million passengers per day in the National Airspace System (NAS). Assuming each passenger carries two to three lithium-ion battery-powered PEDs, this translates to approximately 2.3 billion lithium-ion battery-powered devices brought into aircraft passenger cabins per year in the NAS. This means the likelihood of encountering an overheat or HEF event has also increased.
Crewmembers should exercise extreme caution when approaching an electronic device that is overheating, smoking, deforming, or on fire. The following procedures are recommended for mitigating the risk of an HEF on board an aircraft. Operator procedures and training should include the following three basic concepts:
• Recognizing overheat indicators and actions necessary to prevent a device from starting an HEF or going into TR.
• Extinguishing an HEF fire with the appropriate extinguisher.
• Cooling, containing, and monitoring procedures as the final steps.
14.8.1 Recognizing the Early Warning Signs of PED Overheating. Early recognition of a possible overheat situation of a PED by a crewmember may be able to prevent a potential/imminent TR from causing an HEF. The objective is to stop the device from overheating, thereby preventing the introduction of smoke, flames, or fire in the aircraft environment. HEFs are unique and may not present or progress in the same manner as other fires. In some situations, an HEF can start quickly, but in other situations, the buildup to an HEF can take a little longer. For example, devices prior to TR may show signs of overheating. The overheat can manifest in different ways depending on the device, including warning statements, discoloration of screens, smoking, expanding or swelling of the device, or simply being hot to the touch.
14.8.2 E xtinguishing an HEF. The steps to extinguish an HEF are similar to fighting other fires in the aircraft cabin with the exception of the possible volatile nature of an HEF. Quick and aggressive action is necessary 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 equipment and resources, which may include deadheading crewmembers or ABPs. Procedures for extinguishing an HEF include:
1. C learing occupants from the area around the device.
2. Donning personal protective equipment (PPE) (e.g., gloves or PBE).
3. Obtaining appropriate firefighting equipment (a halon or water extinguisher or another acceptable extinguishing product).
4. Approaching the device with appropriate caution and only getting as close as necessary to effectively extinguish flames and mitigate smoke generation.
14.8.3 C ooling and Containing. Cool a smoking, overheating, or deforming device with water, nonalcoholic beverages, a water extinguisher, or an aqueous-based extinguisher. The most effective cooling is achieved by ensuring the liquid gets inside the device. This may necessitate discharging liquid into any openings within the unit or that may be formed as a result of a PED failure. PBE should be worn to protect the crewmember from fumes.
Crewmembers should do the following:
1. Al l flightcrew members should wear oxygen masks with regulators set to 100 percent oxygen if a fire extinguisher is to be discharged in the flight deck.
2. Continue to cool the device and let it rest without touching it for at least 10 to 15 minutes.
3. Use protective gloves, such as oven gloves or fire gloves, if available, and place the device in a container (e.g., trash bin, galley compartment bin, containment product, or other suitable container that is capable of containing and maintaining a device submerged in water).
4. Fill the container/containment device with water or nonalcoholic liquid to completely submerge the device.
5. Place in a secured area that is accessible to the cabin crewmembers but removed from passengers and will prevent spillage.
6. Monitor the device and surrounding area for the remainder of the flight and provide status updates to the pilot in command (PIC).
WARNING 1: Picking up and moving a smoking or burning device may cause injuries.
WARNING 2: Crewmembers should not cover the device or use ice to cool the device. Ice or other materials insulate the device, increasing the likelihood that additional battery cells will reach TR.
14.8.4 F lightc rew Member Actions in the Event of a Device Overheating on the Flight Deck.
PED overheat warning signs on the flight deck are similar to those in the cabin but may be easier to detect because of the close proximity of the devices to the flightcrew. If overheat is detected:
1. On e flightcrew member should establish control of the aircraft and consider immediate descent and landing at the nearest suitable airport.
2. Disconnect the device from power or attempt to power off the device.
3. Douse the device with water or nonalcoholic liquids to cool the device.
4. In some cases, if necessary, remove the device from the docking station and then quickly remove it from the flight deck.
5. If practical, when the device can be safely moved, place it in a containment device filled with enough liquid to submerge the device.
6. Signal and coordinate with the cabin crewmembers to alert them to opening the flight door to quickly move the device out of the flight deck and into a secure location in the cabin.
14.8.5 Flightcrew Member Actions in the Event of an HEF on the Flight Deck.8 Flightcrew members should take the following immediate actions:
8 Refer to the Portable Electronic Device (PED) Fire Training – Flight Deck vi deo.
1. One flightcrew member should establish control of the aircraft and consider immediate descent and landing at the nearest suitable airport.
2. Flightcrew members should don smoke goggles and oxygen masks at the first indication of smoke or fumes and before accomplishing any abnormal or emergency procedures associated with smoke or fume removal.
3. Flightcrew members should immediately use a fire extinguisher to fight the fire.
4. Flightcrew members should signal and coordinate with the cabin crewmembers to don PPE before assisting with the device removal process. Where applicable, F/As should prepare a makeshift containment and cooling area in accordance with HEF-approved training.
5. The most effective cooling is achieved by ensuring the liquid gets inside the device.
This may necessitate discharging liquids into any openings formed by the separation of the screen from the unit.
6. Extreme caution should be exercised when handling the device. During TR, external temperatures of the device could exceed 500 °F.
7. Though tablet devices may have a lower probability of propagation of the event to other battery cells, they should be treated as though there is a risk of additional TR events until the device is adequately cooled.
8. Flightcrew members should coordinate with the cabin crewmembers the need for a containment device prior to moving the device out of the flight deck to a secure location in the cabin.
WARNING: Picking up and move a smoking or burning device may cause injuries.
15 FLIGHTCREW MEMBER ACTIONS IN THE EVENT OF AN IN-FLIGHT FIRE.
Flightcrew members should:
1. Immediately don their oxygen masks and verify that the regulator is set to 100 percent.
2. Plan for an immediate descent and landing at the nearest suitable airport.
3. Not use smoke/fume elimination procedures to combat a fire.
4. Use smoke/fume elimination procedures to evacuate pollutants.
5. Not reset circuit breakers once the fire is extinguished unless required for safe flight.
15.1 Emergency Landings. Technical evaluations and actual experience indicate that flightcrew members should immediately follow company-approved emergency procedures, notify air traffic control (ATC), and begin planning for an emergency landing as soon as possible. The vast majority of events in the cabin are controlled and do not necessitate an emergency landing. In the event of a hidden fire, delaying descent by only a couple of minutes may make the difference between a successful landing and evacuation and the complete loss of the aircraft.
15.2 Notification. If there is a fire, flightcrew members should notify the F/A(s) to prepare the passengers for an emergency landing and evacuation in accordance with company procedures. If appropriate, flightcrew members should notify the F/As to assist in fighting the fire.
15.3 Checklists. Smoke, fire, or fumes checklists should include, as the first step, that flightcrew members don their oxygen masks and verify that the regulator is set to 100 percent. Flightcrew members should don smoke goggles and oxygen masks at the first indication of smoke or fumes and before accomplishing any abnormal or emergency procedures associated with smoke or fume elimination in accordance with company procedures, the manufacturer’s recommendations, or both. Any delay might result in a crewmember’s incapacitation.
15.4 Smoke and Fume Elimination. Smoke and fume elimination procedures are designed primarily to evacuate the cabin of foreign pollutants. These procedures are not designed to eliminate the cause of the pollutant but rather to increase the aircraft’s airflow to evacuate the pollutant. If the cause of the pollutant is an unextinguished fire, using smoke and fume elimination procedures may worsen the situation by increasing airflow through the area where the fire or smoldering condition exists. For this reason, it is important to extinguish the fire first. If the original source of the fire cannot be determined, exercise caution when attempting to eliminate smoke and fumes from the aircraft. A flightcrew
17 member’s best defense is to have a good understanding of the aircraft’s ventilation and pressurization systems and the location of major components within the fuselage.
Flightcrew members should not delay taking corrective action in accordance with company-approved procedures for any reason.
15.5 PBE Use. If a flightcrew member is needed to assist in fighting a cabin fire, the FAA recommends they don PBE before leaving the flight deck.
16 F/A ACTIONS IN THE EVENT OF AN IN-FLIGHT FIRE. Company procedures should specify how to handle a fire emergency.
16.1 Recommended Actions.9 It is recommended that F/As take the following steps for general or lithium battery fires:
9 Refer to the Portable Electronic Device (PED) Fire Training – Cabin vi deo.
16.1.1 General.
1. Be aggressive; if flames are visible, fight the fire immediately.
2. Immediately notify the flightcrew members and describe the fire, smoke, smells, action being taken, etc.
3. If flames are not visible, find the base or source of the smoke.
4. Pull circuit breakers in the applicable area.
5. Do not reset circuit breakers unless instructed by a flightcrew member.
6. Relocate passengers as necessary.
7. Locate hot spots using the back of one’s hand.
8. Don PBE (as necessary).
16.1.2 F ighting a Fire Involving Lithium Batteries (Disposable/R echargeable Battery or Battery Pack).
1. Relocate passengers away from the device.
2. Utilize a halon, halon replacement, or water fire extinguisher to prevent the spread of the fire to adjacent battery cells and materials.
3. Pour water or another nonalcoholic liquid over the cells immediately after knock down or extinguishment of the fire. Only water or other nonalcoholic liquid can provide sufficient cooling to prevent reignition, propagation, or both of the fire to adjacent batteries. Water, though it may react with the tiny amount of lithium metal found in a disposable battery, is most effective at cooling remaining cells, stopping TR, and preventing additional flareups. Significant cooling is needed to prevent the spread of fire to additional cells in a battery pack.
16.2 Team Approach. One method that may be beneficial is to consider using a team approach to combat a fire. The team approach consists of using flightcrew members and multiple F/As to assist in combating the fire. The team approach is modifiable to fit any number of participants greater than one.
16.2.1 Firefighter. The crewmember (typically an F/A) who finds the fire is usually designated as the firefighter. The firefighter aggressively attempts to locate the source of the fire, fights the fire, and actively tries to extinguish the fire.
16.2.2 C ommunicator. A second crewmember may serve as a communicator. The communicator relays factual information to the flight deck, including the location, source, and severity
(e.g., the fire is under control, spreading, contained, or extinguished) of the fire, the number of fire extinguishers used, smoke conditions, and what is being done to extinguish the fire (e.g., prying apart paneling or discharging an extinguishing agent into the sidewall or overhead area). The communicator also makes announcements to keep passengers informed and calm.
16.2.3 R unner. Another crewmember may serve as a runner. The runner should assist by:
1. Obtaining additional firefighting supplies;
2. Preparing the containment area with water or nonalcoholic liquid in the appropriate container to submerge the PED, if necessary;
3. Relocating passengers;
4. Distributing towels for passengers to use to cover their noses or mouths to filter out smoke;
5. Ensuring aircraft or therapeutic oxygen bottles or both are moved out of the immediate area; and
6. Generally assisting with firefighting support activities as needed.
16.3 Single F/A Operation. In a single F/A operation, when a fire is suspected, immediate communication and coordination with the flight deck is critical. The F/A should follow established company procedures. The F/A performs a variety of tasks with the most important being aggressively pursuing and extinguishing the fire and utilizing passengers, as needed, to support the firefighting efforts (e.g., relocating passengers, runner, etc.).
17 FAA CONCERNS ABOUT RESETTING TRIPPED (POPPED) CIRCUIT BREAKERS IN FLIGHT.
17.1 Resetting Circuit Breakers in Flight.
17.1.1 The FAA reiterates its concern about resetting circuit breakers during flight.
Crewmembers may create a potentially hazardous situation if they reset a circuit breaker without knowing what caused it to trip. Tripped circuit breakers should not be reset in flight unless doing so is consistent with explicit procedures specified in the approved operating manual used by the flightcrew members or unless, in the judgment of the captain, resetting the circuit breaker is absolutely necessary for the safe completion of the
19 flight. A detailed entry in the aircraft’s maintenance log is a proven safety practice for tracking purposes and may provide maintenance personnel with key information to enable prompt troubleshooting and effective corrective action on the ground.
17.1.2 Operator manuals and training programs should contain company policies and explicit procedures regarding resetting tripped circuit breakers, both during flight and on the ground. The procedures shown in the manuals used by the operator’s crewmembers, maintenance personnel, and airplane ground servicing personnel should be consistent with the airplane manufacturer’s guidance. Crewmembers should be reminded not to use a circuit breaker as a switch to perform procedural functions unless doing so is specified in approved company procedures or the manufacturer’s operating procedures.
17.2 Potential Hazards Associated With Tripped Circuit Breakers. The FAA previously published guidance material that states that circuit breakers are slow-acting devices and may not offer sufficient disconnect protection during events such as arc tracking or insulation flashover (refer to AC 25-16). Arc tracking is a phenomenon in which a conductive carbon path forms across an insulating surface. The carbon path provides a short circuit path through which current can flow (e.g., electrical arcing). The effects of electrical faults can include:
• Component overheating;
• Toxic fumes;
• Smoke;
• Fire;
• Damage to wires, wire bundles, or parts;
• Melting of holes in sheet metal parts by faulted, high-current feeder cables;
• Melting and burning of titanium bleed air ducts by a chafed, high-current feeder cable;
• Electromagnetic interference (EMI) with equipment; and
• The simultaneous and unreasonable loss of both engine-driven generators in a two-engine airplane.
Note: AC 25-16 contains additional information about this subject.
17.3 Using a Circuit Breaker as an On/Off Switch. Since circuit breakers are designed to open an electrical circuit automatically at a predetermined overload of current, they should not be used for day-to-day operational functions because they would not be performing their intended function, which is protection against overloads. Circuit breakers should not be used, even those suitable for frequent operation, as a switch to turn protected items on or off. An operator should publish and include in its approved maintenance programs and flight operations manuals any exceptions to this procedure.
20 18 RECOMMENDED TRAINING.
18.1 Training Programs. Operators’ crewmember training programs should stress the importance of crewmembers taking immediate and aggressive action when confronted with smoke, fumes, and in-flight fires. It should also emphasize accessing and fighting hidden fires.
18.2 Training. Operators should include the following knowledge and skill objectives in their crewmember training programs:
18.2.1 Knowledge-Based Objectives:
1. In the event of a known or suspected in-flight fire, crewmembers should know how to take immediate and aggressive action to locate the source of the fires.
2. To assist in locating the source of the fires, crewmembers should know the various aircraft cabin configurations (e.g., overhead, sidewall, cheek, and tunnel areas) the air carrier operates.
3. Crewmembers should understand the proper methods, techniques, or both to gain access to areas that may support hidden fires and the location of any cabin panels that are removable without special tools.
4. Each flightcrew member should understand the aircraft ventilation systems, including normal and abnormal procedures, with emphasis on the potential effects of airflow on hidden fires.
5. To assist flightcrew members in maintaining internal flight deck communications when they don oxygen masks, they should know the aircraft-specific methods for establishing communication.
6. Each flightcrew member should know the importance of stowing their oxygen masks set to 100 percent.
7. To enable crewmembers to locate critical equipment components within the fuselage area, operators’ manuals should contain a cross-section of the aircraft’s fuselage showing the location of electrical, fuel, and hydraulic lines.
8. Crewmembers should recognize potential indications of hidden fires and the importance of not arbitrarily resetting circuit breakers.
18.2.2 Skill-Based Objectives:
18.2.2.1 Flightcrew members should practice the procedures or techniques or both methods associated with:
• Planning for an immediate descent and landing at the nearest suitable airport;
• Aggressively locating the source of smoke, fumes, and fire;
• Notifying cabin crewmembers under non-normal circumstances;
• Operating the aircraft while using PBE and smoke goggles;
• Implementing smoke and fume elimination procedures;
• Alternate means of dispersing smoke and fumes when the source of a fire is unknown; and
• Use of oxygen masks/goggle sets, including the use of the regulator’s emergency selector and the venting of smoke goggles.
18.2.2.2 Cabin crewmembers should practice the procedures or techniques or both methods associated with:
• Aggressively locating the source of the fire;
• Selecting the appropriate extinguishing agent;
• Relocating passengers as necessary;
• Opening storage compartments or doors;
• Considering the location of portable oxygen bottles and considering relocating portable oxygen bottles away from the source of the fire;
• Notifying flightcrew members under non-normal circumstances; and
• Locating hot spots on interior panels.
18.2.2.3 Skill-based training should be conducted jointly (flightcrew with F/As) to emphasize Crew Resource Management (CRM). Crewmember performance should be evaluated in the following areas:
• Clear and concise communication;
• Effective decision making;
• Critical CRM skills, including situational awareness; and
• Time management.
19 OBTAINING FAA PUBLICATIONS.
• This AC is available on the FAA’s website at https://www.faa.gov/regulations_policies/advisory_circulars/.
• FAA handbooks and orders are available online at https://www.faa.gov/.
• The Code of Federal Regulations is available online at https://www.ecfr.gov/.
20 NOTES ON APPENDICES. The following appendices contain information about the dangers associated with in-flight fires. Operators may also use this information to develop training programs in support of the recommendations contained in this AC. The information may vary among fleets and operators and may change over time. Some of the examples may be readily adapted to an operator’s training and operating manuals for
22 various airplane fleets. Others may apply to a certain airplane fleet and may not be adaptable apart from that fleet.
21 AC FEEDBACK FORM. For your convenience, the AC Feedback Form is the last page of this AC. Note any deficiencies found, clarifications needed, or suggested improvements regarding the contents of this AC on the Feedback Form.
Wesl ey L. Mooty Acting Deputy Executive Director, Flight Standards Service
Appendix A A-1 APPENDIX A. FIREFIGHTING BASICS A.1 In order to determine the best way to approach a fire and the safest way to extinguish it, a crewmember should be able to differentiate between different types of fire situations.
Learning how to fight fires involves learning the elements that are involved in creating and sustaining a fire.
A.2 The fire triangle is a model for understanding the necessary ingredients for most fires:
fuel, heat, and an oxidizing agent (usually oxygen). The fire tetrahedron represents the addition of the chemical chain reaction to the three components already present in the fire triangle. Fire can be prevented or extinguished by removing any one of these elements.
Figure A-1. Fire Triangle Fi gure A-2. Fire Tetrahedron A.
3 The fuel in aircraft fires is the materials used to construct the aircraft and its contents, such as insulation, carpeting, ducting, floor and ceiling panels, partitions and sidewalls, seat covers, and curtains. Heat can come from an outside source, such as a match or wire arc, and from the fire itself. The oxidizing agent is a material or substance that, when the proper conditions exist, will release gases, including oxygen. The self-sustained chemical chain reaction is the way the fire’s components react to each other.
Appendix A A-2 A.4 In order to extinguish a fire, and thus break the fire chain, it is necessary to eliminate one of the fire elements. The most common method is to use water, which removes heat by cooling the fire. Additionally, water acts to smother the fire by taking away oxygen.
Similarly, foam fire extinguishers smother fires. Removing the fuel is another firefighting method, such as when a gas line is shut off. Another method of extinguishing fires is by inhibiting the chemical chain reaction. Fire retardant agents interrupt the combustion reaction, which halts the fire.
A.5 One of the major hazards associated with firefighting operations is the toxic environment created by combustible materials. The four major risks are smoke, oxygen deficiency, elevated temperatures, and poisonous atmospheres. Additional hazards include falls and structural collapse that can exacerbate the problems encountered in a toxic environment.
A.6 The first step in a firefighting operation is reconnaissance to search for the origin of the fire and to identify the specific risks.
A.7 A crewmember’s goals when fighting a fire are to save lives, protect property, and protect the environment. A fire can rapidly spread and endanger many lives, but with consistent and appropriate firefighting techniques, catastrophe can often be avoided.
A.8 Learning how to fight fires involves both education and experience. Crewmembers should learn the science of fire, including the causes and components of the fire, and the methods of extinguishing it. They should also learn how to use the tools necessary for firefighting.