# AC 20-42D: Hand Fire Extinguishers for use in Aircraft - Type: Advisory circular (guidance, not mandatory unless a rule or AD requires it) - Status: Current - Approved: January 14, 2011 - Last reviewed: October 30, 2017 - Family: AC 20-42 - Cancels: [AC 20-42C](https://openairdocs.org/ac/20-42C) - 14 CFR parts: 23, 25, 29, 91, 121, 125, 135, 127 - 14 CFR sections: [25.851](https://www.ecfr.gov/current/title-14/section-25.851) - Pages: 48 - PDF: https://openairdocs.org/files/sha256/8f/dd/8fdd53b04f5aff1209890d311de53da360cace6de0a6d533f9410118bd52f539 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5B54C6823103CD96862578290074382B.0001 - DRS record last changed: October 23, 2026 - Page: https://openairdocs.org/ac/20-42 ## Versions - [AC 20-42D](https://openairdocs.org/ac/20-42) (Current), approved Jan 14, 2011, 48 pages - [AC 20-42C](https://openairdocs.org/ac/20-42C) (Historical), approved Mar 7, 1984, 12 pages ## Text Each page's text from the PDF; open the PDF at a page with #page=N. This is OCR from the scanned FAA advisory circular. OCR can misread letters and numbers. ### Page 1 (OCR) Advisory U.S. Department of Transportation Circular Federal Aviation Administration Subject: Hand Fire Extinguishers for use in Aircraft Date: 01/14/11 AC No: 20-42D Initiated by: AIR-120 Change: This advisory circulat (AC) gives you guidance for the fire-fighting effectiveness, selection and safe-use of hand fire extinguishers in airplanes and rotorcraft. In it we will also show you how to gain Federal Aviation Administration (FAA) approval of hand fire extinguishers for aircraft. Susquan Cabler For David W. Hempe Manager, Aircraft Engineering Division Aircraft Certification Service ### Page 2 (OCR) Table of Contents Paragraph Page Chapter 1. General Information about this Advisory Circular (AC)... ... I 1. What is the Purpose of this Advisory Circular (AC)? 1 2. Who is this AC for? .. .. 2 3. What has Changed in this AC from the Previous AC?. 2 4. Does this AC cancel any prior ACs?.. . 3 5. Where Can I find This AC and other FAA publications?.. Chapter 2. Gaining FAA Approval for Fire Extinguishers. ... 4 1. How are Hand Fire Extinguishers Approved?. 4 2. How are Halon 1211 Replacement Extinguishers Approved? 5 3. How are Halon Agents Approved? . 7 Chapter 3. Selecting the Correct Hand Fire Extinguisher. . 9 1. What are the Different Types of Fires?. 2. What do the Numeral Ratings Mean?. 3. What Extinguishing Agents are Appropriate for the Different Types of Fires? 9 4. What Extinguishing Agents are Compatible with Aircraft Materials? 5. What are the Operating Temperature Tolerances? .. 6. General Guidelines for Hand Fire Extinguishers?.. 12 Chapter 4. Safe Use of Hand Fire Extinguishers. .. 14 1. What Basic Fire Fighting Training Should be Provided?. 14 2. What are Some General Guidelines for the Safe-Use of Halocarbon Extinguishers?..... .. 15 3. How to Prevent Hypoxia in an Unpressurized Aircraft. . 16 4. What are the Guidelines on the Selection of Halocarbon Extinguishers?.. …17 5. How to Safely Use Halocarbon Extinguishers in Accessible Cargo Compartments. .. 19 How to Inspect and Maintain the Hand Fire Extinguisher for Continued Safe-Use.. .. 20 = ### Page 3 (OCR) Paragraph Page Chapter 5. Locating and Mounting Hand Fire Extinguishers.. .. 22 1. Where to Locate and Mount Hand Fire Extinguishers in Passenger Compartments... 22 2. How to Locate and Mount Hand Fire Extinguishers in Flight Deck Compartments... 23 3. How to Locate and Mount Hand Fire Extinguishers in Small Single Engine and Multiengine Aircraft..... ...23 4. How Many Hand Extinguishers Should I Install 23 Appendix 1. List of Acronyms. .. A1-1 Appendix 2. Definitions and Terms. . A2-1 Appendix 3. Related Publications and How to Get Them. . A3-1 1. Code of Federal Regulations (CFR). A3-1 2. FAA Airworthiness Directive (AD) A3-1 3. FAA Advisory Circulars (AC) … A3-1 4. FAA Technical Standard Order (TSO) A3-2 5. FAA Safety Alerts for Operators (SAFOS) and Information for Operators (InFOs)... A3-2 6. FAA Training Videos. A3-2 7. Reports and Papers... A3-2 8. American Society of Testing and Materials (ASTM) Standards.. A3-4 9. Factory Mutual Research Corp. (FM) .. A3-5 10. International Organization for Standardization (ISO). .. A3-5 11. National Fire Protection Association (NFPA). .. A3-5 12. RTCA Inc. Documents.. A3-6 13. SAE Documents... .. A3-6 14. Underwriters Laboratories, Inc (UL). .. A3-6 ### Page 4 (OCR) Paragraph Page Appendix 4. Explanatory Material .. • A4-1 1. Effective Throw Ranges.. • A4-1 2. Safe-Use Guidance.. .. A4-1 3. Extinguisher Weights.. A4-4 4. Aircraft Volumes and Ventilation.. .. A4-5 Table of Figures Figure 1. Relative Toxicity of 5 B:C Halocarbon Extinguishers. .18 Figure 2. Minimum Number of Hand Fire Extinguishers Required for Transport Category Aircraft Passenger Compartments. .24 Figure 3. Minimum Number of Hand Fire Extinguishers Required for Transport Category Rotorcraft Passenger Compartments .25 Figure 4. Effective Throw Ranges for Halocarbon Halon Replacement and Water Extinguishers.. A4-1 Figure 5. Safe-Use Agent W/V for Halocarbon Extinguishers in Unventilated Passenger and Crew Compartments. .A4-2 Figure 6. Multiplication Factors (MF Ventilated) for Ventilated Compartments. ..A4-2 Figure 7. Minimum Safe Compartment Volume for One Extinguisher in Unventilated Compartments.. ..A4-4 Figure 8. Fire Extinguisher Performance and Gross Weights. ...A4-5 Figure 9. Aircraft Volumes and Ventilation.. … A4-6 IV ### Page 5 (OCR) Chapter 1. General Information about this Advisory Circular (AC) 1. What is the Purpose of this Advisory Circular (AC)? a. We provide guidance for fire-fighting effectiveness, selection, location and mounting of hand fire extinguishers. b. We establish the halocarbons hydrochlorofluorocarbon (HCFC) Blend B, hydrofluorocarbon (HFC)-227ea, and HFC-236fa as FAA approved replacement agents to Halon 1211 and Halon 1301. c. This AC recommends that you transition to using these new halocarbon clean agents in fire extinguishers kept onboard aircraft and rotorcraft. We explain how to gain certification for halocarbon clean agent extinguishers intended to replace Halon 1211 hand-held extinguishers. d. This AC recommends that dry chemical, dry powder, and carbon dioxide hand extinguishers, in general, should not be used in aircraft. e. We also explain how to gain Federal Aviation Administration (FAA) certification for replacement agent fire extinguishers, which you may use to comply with Title 14 of the Code of Federal Regulations (14 CFR) parts 23, 25, 29, 91, 121, 125, 127, and 135. f. This AC establishes an FAA approved minimum performance standard (MPS) for halon replacement agents which includes a hidden fire test and a seat fire/toxicity test. This AC recognizes that toxicity of halocarbon agents and their decomposition products is a concern and should be a consideration for extinguisher selection. However, given the variability of extinguishers, application, compartment sizes and air change times, establishing specific selection criteria is impractical. The toxicity hazard is a secondary concern to an unextinguished in-flight fire. h. This AC provides new general guidance in the form of safe-use weight per unit volume (W/V) that may be useful in extinguisher selection, and establishes marking criteria for halocarbon extinguishers. i. We show how to reduce the health and safety risk of exposure to halocarbon clean agents and how to use halocarbon clean agent fire extinguishers. j. We offer updated guidance on the continued safe-use of Halon 1211, Halon 1301, and Halon 1211/1301 Halon blend extinguishers. ### Page 6 (OCR) k. This AC is not mandatory and does not constitute a regulation. It is not intended to require you to do anything beyond what is specifically required by the regulations. In it, we describe an acceptable means, though not the only means, to gain certification for fire extinguishers kept onboard aircraft and rotorcraft. However, if you use the means described, you must follow it entirely. 2. Who is this AC for? We wrote this AC for those responsible for selecting, approving, purchasing, and maintaining hand fire extinguishers. The guidance in this AC is also for manufacturers, installers, modifiers, owners, and operators of airplanes and rotorcraft. b. This AC is a method of compliance for transport category aircraft. Operators of nontransport category airplanes or rotorcraft should become familiar with the information, precautions, and the safe-use guidance in this AC. Existing halon handheld fire extinguisher installations are not affected by the updated guidance in this AC. The guidance in prior revisions of this AC applies to specific extinguisher installations on existing approved type design aircraft. These extinguishers remain suitable for continued use based on a history of safe use of halon extinguishers on aircraft. However, although not required for new installations and in-service aircraft where practical, we encourage owners and operators to consider using FAA approved halon replacement extinguishers. 3. What has Changed in this AC from the Previous AC? Replacement halocarbon clean agents were developed in response to restrictions on the production of ozone-depleting halon fire extinguishing agents. The restrictions were introduced under the Clean Air Act Amendments of 1990 which implemented the Montreal Protocol signed September 16, 1987, as amended. In addition, the International Civil Aviation Organization is considering further mandated limits on halon use in aircraft. b. Since 1994, Halon 1211 has not been produced in the U.S. By 2010, Halon 1211 will no longer be produced anywhere in the world. However, recycled Halon 1211 is available for new and existing fire extinguishers. Halocarbon clean agent extinguishers hydrochlorofluorocarbon HCFC Blend B and hydrofluorocarbons HFC-227ea, and HFC-236fa are now commercially available. These halocarbon hand fire extinguishers have been evaluated and found to be effective fire-fighting agents. If properly used, these agents are safe to human c. Safe-use guidance is provided for Halon 1211 and Halon 1301 and blends of these agents. Safe-use concentrations of Halon 1211 are lower than in the previous AC, because the guidance in this AC is more conservative. ### Page 7 (OCR) Does This AC Cancel Any Prior ACs? This AC cancels AC 20-42C, dated March 7, 1984. 5. Where Can I find This AC and Other FAA Publications? You can find this AC on the Regulatory and Guidance Library (RGL) website: http://rgl.faa gov/. See appendix 3 in this AC for additional information and related documentation. ### Page 8 (OCR) Chapter 2. Gaining FAA Approval for Fire Extinguishers 1. How are Hand Fire Extinguishers Approved? Federal Regulations for Hand Fire Extinguishers. Hand fire extinguishers are required under 14 CFR §§ 23.851, 25.851(a)(1), 29.851(a)(1), 29.853(e) & (f), 91.513(c), 119.25, 121.309(c), and 135.155. We approve hand fire extinguishers to be used on aircraft under the provisions of 14 CFR § 21.305(d). Accordingly, this AC is provided as one means acceptable to us for the approval of hand fire extinguishers, other than water solution extinguishers approved under TSO-C19. Note: Although 14 CFR parts 91 and 125 don't require our approval of hand fire extinguishers, we consider the information in this AC acceptable for use by Part 91 and 125 operators. b. Extinguishers Approved Under Industry Standards Organizations. We approve hand fire extinguishers for use in aircraft when they meet industry standards. Extinguishers approved in this manner should also meet the safe-use guidance provided in this AC. In addition, replacement agents must meet additional requirements specified in paragraph 2 below. We accept hand fire extinguishers approved by: (1) U.S. - Underwriters Laboratories, Inc. (U.S. - UL) according to U.S. - UL Standard 711, Rating and Fire Testing of Fire Extinguishers, and U.S. - UL construction and performance requirements for specific agent extinguishers with a U.S. - UL Listing mark (See paragraph 3c below.) or equivalent such as: (2) Factory Mutual Research Corporation (FM) with listing mark, or (3) The U.S. Coast Guard (USCG) with marking per 46 CPR § 162.028. Minimum Rating. Your hand fire extinguisher should be rated per the requirements of U.S. - UL 711, dated December 17, 2004 or equivalent, as noted in paragraph 1b above. Hand extinguishers produced in the U.S. or those used on airplanes and/or rotorcraft operated within the U.S. should meet U.S. - UL fire rating standards. (1) Large Aircraft. The required hand extinguishers should be listed and have a minimum U.S - UL 5B:C rating or the equivalent. Exception: See chapter 4, paragraph 5 of this AC for minimum extinguisher ratings for use in accessible cargo compartments. (2) Small Airplanes or Rotorcraft. You may use an extinguisher with a minimum rating of U.S. - UL 2B:C or equivalent on aircraft with maximum compartment volumes of up to 200 R'. ### Page 9 (OCR) How are Halon 1211 Replacement Extinguishers Approved? Hand extinguisher replacement agents, such as the halocarbon clean agents intended to replace the required 2½ pound U.S. - UL. SB:C Halon 1211 extinguishers, may be approved for use on aircraft if the agent complies with the tollowing requirements: a. Replacement Agent Health and Environment Approval. (1) Evaluate any halon replacement agent using the U.S. Environmental Protection Agency (EPA) Significant New Alternatives Policy (SNAP) program according to 40 CFR part 82, subpart G. This process characterizes the health and environmental risk of a proposed replacement agent. The three halon replacement agents covered by this AC were evaluated under the SNAP program. Halocarbon clean agents HCFC-Blend B, HFC-227ea, and HFC-236fa are approved for environmental and toxicological acceptability. b. Replacement Agent Hand Extinguisher MPS. Evaluate the replacement agent/extinguisher using the two fire tests specified in the MPS technical report cited in appendix 3 paragraph 7s. MPS testing of replacement agents should be coordinated with and approved by your local ACO with the support of FAATC. These fire tests ensure that the replacement agent extinguishers provide equivalent fire fighting performance to Halon 1211. Clean agent extinguishers designed to replace the required 2½ pound Halon 1211 extinguisher onboard aircraft should comply with the following MPS provisions: Hidden Fire Test. The hidden fire test evaluates the "flooding" characteristics of the replacement agent against a hidden in-flight fire and determines the ability of a streaming agent to function as a flooding agent. This is a hardware-specific test and the extinguisher design affects its performance. Each required 5B:C extinguisher model should pass this test to be certified as a Halon 1211 replacement on aircraft. Seat Fire/Toxicity Test. The seat fire test is a baseline test that evaluates the effectiveness of the replacement agent in fighting a flammable fluid seat fire scenario and the associated toxicity hazard of the decomposition products of that agent. This test measures the agent's ability to extinguish a triple-seat fire in an aircraft under in-flight conditions and ensures an acceptable level of toxicity for the thermal decomposition products of the replacement agent. If a particular required 5B:C extinguisher model passes the seat fire/toxicity test, other models of extinguishers do not need to be tested, if the same agent is used. Note 1: Select a replacement agent or halocarbon extinguisher for your aircraft compartment according to the fire rating per its U.S - UL listing, not the agent weight. Note 2: The effectiveness of a hand fire extinguisher relies upon the training, expertise and capabilities of the crew member utilizing the device. ### Page 10 (OCR) (3) HCFC-Blend B, HFC-227ea, and HFC 236fa have demonstrated to meet the MPS and are approved for use. C. National Certification. U.S. - UL 2129, Halocarbon Clean Agent Fire Extinguishers, dated January 3, 2007 with a required rating of U.S. - UL 5B:C or equivalent per U.S. - UL 711 or equivalent (see paragraph 1b above). Note: Use the FAA approval marking label, (see paragraph 2e below) and the U.S - UL numeric rating listing, not the agent weight to select extinguishers for an aircraft compartment. d. Specifications for Approved Halocarbon Clean Agents to Replace Halon 1211. For hand fire extinguishers employing halocarbon clean agents replacing Halon 1211, the following American Society of Testing and Materials (ASTM) specifications apply: (1) HCFC Blend B must meet ASTM D 7122-05, Standard Specifications for HCFC Blend B; (2) HFC-227ea must meet ASTM D 6064-03, Standard Specifications for HFC-227ea, 1,1,1,2,3,3,3-Heptaflouropropane (CF;CHFCFs); (3) HFC-236fa must meet ASTM D 6541-05, Standard Specification for HFC-236а, 1,1,1,3,3,3-Hexafluoropropane (CFSCH 2CF 3); ot (4) New Halon 1211 replacement agents must have and meet an applicable ASTM or equivalent specification. (5) Fire extinguisher manufacturers are responsible for the validation of agent purity whether using new or recycled agent. Marking. If you are a manufacturer, each of your models of U.S. - UL 5B:C Halon 1211 replacement extinguishers that have passed the test specified in paragraph 2b(1) and 2b(2) above should be permanently and legibly marked with the following: (1) "Meets FAA approved MPS per DOT/FAA/AR-01/37" (2) The name of the listing agency and rating according to U.S. - UL 711 or equivalent. U.S. - UL extinguishers must have the UL listing mark (include UL copyright logo) with the four required elements: UL in circle mark; word "listed;" product or company name; and issue/serial number or control number. f. New Technologies and Extinguishers Containing New Replacement Agents. Nothing in this AC is intended to restrict new technologies or use of new replacement agents provided they meet the regulations and guidance prescribed in paragraph 2 above. ### Page 11 (OCR) (1) New agents introduced after the effective date of this AC should comply with the provisions of paragraph 2a through 2e above. (2) If the documentation needed in paragraph 2f(1) is not yet officially published for a particular halocarbon agent, use the NOAEL values approved under the SNAP program mentioned in paragraph 2a(1) above. They can be obtained from the SNAP Program Coordinator at the EPA Office of Air and Radiation or on the public docket for that office and used to determine safe-use W/Vs in the absence of published FAA safe-use guidance. Safe-use W/Vs may be calculated using EPA's NOAEL values following the methodology outlined in appendix 3 reference paragraph 7m of this AC. (3) The FAA Technical Center (FAATC) intends to publish future guidance on handheld extinguishers. This guidance will include safe-use W/V for ventilated compartments using FAA approved fire extinguishers containing halon replacement agents introduced after the issuance of this AC. 3_ How are Halon Extinguishers Approved? a. National Certification. Required halon hand-held fire extinguishers approved for use on aircraft should have a minimum rating of UL 5B:C. Halon 1301 and Halon 1211/1301 blends are also used. Halogenated fire extinguishers must comply with U.S. - UL 1093, Halogenated Agent Fire Extinguishers, or equivalent, for Halon 1211, Halon 1301 and Halon 1211/1301 blends per U.S. - UL 711 or equivalent (see paragraph 1b above). It should be noted that on March 12, 2009, UL announced the withdrawal of US - UL 1093 and the continuance of existing certifications to the withdrawn US - UL 1093. UL will no longer accept the submittal of new or revised products, but all current compliant products covered under US - UL 1093 will continue to be authorized to bear the classification mark of Underwriters Laboratories Inc. until October 1, 2014. b. Specifications for Approved Halon Agents. For hand fire extinguishers that still employ halogenated agents, only Halon 1211, Halon 1301, or blends of the two have been previously approved and used aboard aircraft. The following specifications cover the requirements for halogenated agents: (1) Halon 1211 should meet the requirements of ASTM D7673-10, Standard Specification for Halon 1211-Bromochlorodifluoromethane (CF¿CIBr)), or ISO 7201-1:1989, Fire protection -- Fire extinguishing media - Halogenated Hydrocarbons - Part 1: Specifications for Halon 1211 and Halon 1301. (2) Halon 1301 should meet the requirements of ASTM D5632-08, Standard Specification for Halon 1301-Bromotrifluoromethane (CF Br)), or ISO 7201-1:1989. ### Page 12 (OCR) (3) Hand fire extinguishers with halon agents may continue to be used on aircraft as long as recycled halon of proven acceptable quality is available. Recycled agents are still available for purchase, but the duration of their availability is unknown. Therefore, we encourage operators to consider replacing halon extinguishers after discharge with approved halon replacement extinguishers. (4) An EPA exemption allows the production of halon blends from recycled halon for aircraft use. There are strict conditions to this exemption. (5) Fire extinguisher manufacturers are responsible for the validation of agent purity whether using new or recycled agent. Marking. If you are a manufacturer, mark your halon extinguishers permanently and legibly with the name of the listing agency and rating according to U.S. - UL 711 or equivalent. U.S. - UL extinguishers must have the UL listing mark (include UL copyright logo) with the four required elements: UL in circle mark; word "listed;" product or company name; and issue/serial number or control number. FM extinguishers must have the FM listing mark. And, USCG extinguishers must have the "USCG approval 162.028/XX" marking. ### Page 13 (OCR) Chapter 3. Selecting the Correct Hand Fire Extinguisher 1. What are the Different Types of Fires? Classes of Fires. To properly select an appropriate hand fire extinguisher for use in an aircraft, you should consider the following classes of fires that are likely to occur onboard your aircraft, as defined in the appendix 3, paragraph 1 la of this AC. (1) Class A. Fires involving ordinary combustible materials, such as wood, cloth, paper, rubber, and plastics. (2) Class B. Fires involving flammable liquids, petroleum oils, greases, tars, oil base paints, lacquers, solvents, alcohols, and flammable gases. (3) Class C. Fires involving energized electrical equipment where the use of an extinguishing media that is electrically nonconductive is important. (4) Class D. Fires involving combustible metals, such as magnesium, titanium, zirconium, sodium, lithium, and potassium. Lithium Battery Fires. Do not treat a fire involving a small number of lithium batteries as a Class D fire. We consider a small number of rechargeable lithium batteries as what would be found in portable electronic devices (PED) e.g. laptop computers, cell phones, pagers, audio/video/data recording or playback devices, messaging devices, personal digital assistants (PDAs), and two-way radios. See chapter 4 paragraph 1f of this AC on fire fighting training for further information. 2. What do the Numeral Ratings Mean? The labeling on fire extinguishers consists of numerals and letters used in combination to describe the extinguishers relative effectiveness on a specified Class/type(s) of fire(s). Numerals are used with identifying letters for extinguishers labeled for Class A and Class B fires. The "numeral," which precedes the letter, indicates the relative extinguishing effectiveness of the device on a given size fire. This is dependent on the agent, the capacity of the device, discharge times, and design features. For example, an extinguisher rated as U.S. - UL 4A should extinguish about twice as much Class A fire as a U.S. - UL 2A rated extinguisher. Numeral ratings are not used for extinguishers labeled for Class CorD fires. Extinguishers that are effective on more than one class of fires have multiple "numeral-letter" and "letter" classifications and ratings; for example, U.S. - UL 5B:C. ### Page 14 (OCR) b. Additional Rating Guidelines for Halocarbon Extinguishers. For occupied spaces on transport category aircraft, extinguishers employing halocarbon clean agents, replacing required Halon 1211 extinguishers, should have a minimum U.S. - UL 5B:C or an equivalent rating. Halocarbon extinguishers are most effective on Class B and C fires. Extinguishers with greater capacity are also rated for Class A fires. Extinguishers with a 2B:C or 5B:C U.S. - UL rating, although not rated for use on Class A fires, have been shown to be effective in extinguishing surface Class A fires. 3. What Extinguishing Agents are Appropriate for the Different Types of Fires? The following extinguishing agents are appropriate for use on the types of fires specified in paragraph la above: a. Water. Class A type fires are best controlled with water by cooling the material below its ignition temperature and soaking the material to prevent re-ignition. b. Carbon Dioxide. Class B or C fires are effectively controlled by carbon dioxide as a blanketing agent. Note: Carbon dioxide is not recommended for hand-held extinguishers for internal aircraft use. Dry Chemicals. Class A, B, or C fires are best controlled by dry chemicals. The only "all purpose" (Class A, B, C rating) dry chemical powder extinguishers contain monoammonium phosphate. All other dry chemical powders have a Class B, C U.S - UL fire rating only. Note 1: In general, dry chemicals are not recommended for hand extinguishers for internal aircraft use, due to the potential for corrosion damage to electronic equipment, the possibility of visual obscuration if the agent were discharged into the flight deck area, and the cleanup problems from their use. Note 2: When approving a non-gaseous agent for installation on aircraft, evaluate the contamination impact to the structure, wiring and surrounding systems, and consider potential mixing of the agent residue with water. Using such extinguishers may require specific maintenance procedures addressing cleanup. d. Halons. Class A, B, or C fires are appropriately controlled with halons. However, do not use halons on a class D fire. Halon agents may react vigorously with the burning metal. Note: While halons are still in service and are appropriate agents for these classes of fires, the production of these ozone depleting agents has been restricted. Although not required, consider replacing halon extinguishers with halon replacement extinguishers when discharged. ### Page 15 (OCR) Halocarbon Clean Agents. (Halons are a subcategory of halocarbons.) Class A, B, or C fires are appropriately controlled with the use of halocarbon clean agents. Never discharge halocarbon clean agents or water on a Class D (burning metal) fire. Halocarbon agents may react vigorously with the burning metal. f. Specialized Dry Powder. Class D fires are best controlled by dry powder. Follow the recommendations of the extinguisher manufacturer because of the possible chemical reaction between the burning metal and the extinguishing agent. Note 1: Specialized dry powder is not recommended for hand extinguishers for internal aircraft use. Note 2: Fires involving a small number of Lithium primary batteries (containing molten Lithium) should not be treated as class D fires and specialized dry powder should not be used. See chapter 4, paragraph 1f of this AC for a discussion of appropriate extinguishing agents for Lithium battery fires. 4. What Extinguishing Agents are Compatible with Aircraft Materials? Corrosion by Extinguishing Agents. Halocarbon clean agents are not corrosive, but review the material compatibility properties for acceptability to aircraft materials. Water itself is not corrosive, but may be rendered corrosive by the addition of antifreeze solutions. Specialized dry powder and monammonium phosphate dry chemical are corrosive to most sensitive electronic components and instruments. b. Material Compatibility. Halocarbon clean agents can be used in numerous aircraft applications and it is important to review the materials of construction for compatibility when designing new equipment, retrofitting existing equipment, or preparing storage and handling equipment to incorporate halocarbon clean agents. Materials that should be considered include metals, elastomers, and plastics. Halocarbon clean agents or water should never be discharged on Class D (burning metal) fires. These agents may react vigorously with the burning metal. See paragraph Ib above for the exception: Lithium battery fires involving carry-on appliances. c. Corrosivity of Decomposition Products. The thermal decomposition products of halocarbon extinguishing agents are corrosive, particularly the acid halides: HF, HCI and HBr. The decomposition products of burning aircraft materials are also corrosive. Yet decomposition products are minimized by quickly extinguishing the fire. Acid halide production is also based on the agent used and the size of the fire. What are the Operating Temperature Tolerances? Halocarbon clean agent extinguishers should operate properly after being conditioned at -40°F (-40°C) or -65°F (-54°C) as applicable and 120°F (49°C) for 16 hours as specified in U.S. - UL 2129 or U.S. - UL 1093, as applicable. Water extinguishers should be protected to -40°F (-40°C) by adding antifreeze and stipulated on the extinguisher nameplate. ### Page 16 (OCR) Cold operation may require additional consideration in the selection of an extinguisher. This is particularly true for general aviation aircraft in extremely cold climates. The hidden fire extinguishment tests in the MPS were conducted on halocarbon extinguishers equilibrated to 70°F. More agent, a lower boiling point agent, or an extinguisher design change, may be needed to extinguish hidden fires. Testing may be needed to select an appropriate extinguisher. The boiling points of the halocarbons (at 1 atmosphere) listed in this AC are: (1) HCFC Blend B = 80.6°F (27.0°C), (2) HFC-227ea 1.9°F (-16.4°C), (3) HFC-236fa = 29.5°F (-1.4°C), (4) Halon 1211 = 26.0°F (-3.4°C), and (5) Halon 1301 = -72.0°F (-57.8°C). 6. General Guidelines for Hand Fire Extinguishers. a. Consider the effects of agent toxicity, aircraft ventilation, agent stratification and hypoxia when selecting and sizing the necessary fire extinguisher for your specific application. Chapter 4 of this AC provides more details. Provide the required minimum number of hand held extinguishers. See chapter 5, paragraph 4 of this AC. All extinguishers must have the proper U.S. - UL rating, even in spaces where the safe use guidelines, as outlined in chapter 4 paragraphs 2, 4, 5, and 6 of this AC, are exceeded. The failure to extinguish a fire has catastrophic consequences for all aircraft occupants. Agent toxicity should be considered secondary to the immediate need to extinguish the fire. Follow the safe-use guidance recommendations in chapter 4 of this AC for selecting extinguishers for your aircraft compartments to, "...minimize the hazard of toxic gas concentration...", mentioned in 14 CFR §§ 23.851(c)(2), 25.851(a)(8), and 29.851(a)(3). d. Do not substitute two smaller extinguishers for one extinguisher of the proper UL rating, except as provided for accessible cargo compartments, as noted in chapter 4, paragraph 5c of this AC. The fire can grow quickly prior to the discharge of the second extinguisher. e. Due to the relatively short discharge time of hand fire extinguishers: a U.S. - UL 5B and a U.S. - UL 1A: 10B:C rated extinguisher at approximately 8 seconds; and 13 seconds for a U.S. - UL 2A:10B:C extinguisher; training on the proper use of the fire extinguishers is very important. ### Page 17 (OCR) f. For access to under seat, overhead, and other difficult to reach locations, hand extinguishers equipped with a discharge hose or adjustable wand mounted directly to the extinguisher are highly recommended. A discharge hose or adjustable wand is preferred because it is likely to result in the extinguisher being properly held in an upright position during use and provides a means of directing a stream of agent to more inaccessible areas. Adjustable wand or fixed nozzle extinguishers allow for one-handed use. See AC 120-80 for more details and guidance on in-flight fire fighting. A video for flight crew training is available from the FAA. The title of the video is "Aircraft In-flight Fire Fighting." The tape version of the video is referenced as "MST 730" and the DVD version is referenced as "MST 730.01." It can be obtained from Dale Dingler, FAA William J. Hughes Technical Center, Advanced Imaging Division, AJP-7960, Atlantic City International Airport, NJ 08405, phone: (609) 485-6646, email:dale.dingler@faa.gov. The in-flight training video is also available at the following public website: http://www.fire.tc.faa.gov/2007Conference/session_details.asp?sessionID=26. g. U.S. - UL 5B:C extinguishers should have no less than an & foot (3 m) throw range (passing the MPS seat tests assures a 8 foot throw range). Longer throw ranges of 10 feet and greater provide a significant advantage in fighting fires in large transport category aircraft. See appendix 4, paragraph 1 of this AC for more information on replacement agent throw ranges. h. Halocarbons that are gaseous upon discharge have a more limited throw range. Halocarbons have discharge characteristics dependent on the halocarbon, nozzle design, extinguisher super pressurization, cold soak times, and operational temperatures. 7. Replacement of TSO Water Extinguishers: a. Halon replacement extinguishers with a minimum rating of 5B:C can be used in place of required technical standard order (TSO) C19 water extinguishers, if you can show that the replacement extinguisher has comparable or better Class A extinguishing performance than the TSO'd water extinguisher. A TSO C19 water extinguisher can fight small Class A fires but are not large enough to have a 1A rating. The halon replacement extinguisher must have a sufficient throw range to extinguish fires likely to occur. b. For aircraft that are required to carry two or more extinguishers and two water extinguishers are in close proximity, the two water extinguishers may be replaced by one halon replacement extinguisher. This is allowed only if the extinguisher has been shown to have comparable or better Class A fire extinguishing capability as both water extinguishers and a sufficient throw range to extinguish fires likely to occur. ### Page 18 (OCR) Chapter 4. Safe Use of Hand Fire Extinguisher 1. What Basic Fire Fighting Training Should be Provided? a. Flight crewmembers should be trained on the urgency of immediate and aggressive extinguishment of an onboard fire. As fires can grow exponentially with time, the risks of exceeding the hazardous concentration levels of extinguishant are considered minimal compared to the risks of an in-flight fire. (1) Quickly extinguish the fire. (2) Immediately turn off all air recirculation systems, as permitted by your flight manual. b. Train flight crewmembers on the proper use of hand extinguishers. See AC120-80, In-Flight Fires, for additional guidance. A training video on the use of hand extinguishers to fight on-board fires is available at the following website: http://www.fire.tc.faa.gov/2007Conference/session_details.asp?sessionID=26. c. Operators should ensure that all crew members receive proper training in the appropriate use of hand fire extinguishers onboard their aircraft d. Attack the base of the fire at the near edge of the fire and then move the fire extinguisher nozzle with a side-to-side sweeping motion, progressing toward the back of the fire. The optimum firefighting technique differs for each approved extinguisher. e. Do not direct the initial discharge at the burning surface at close range, if the burning material might splash and/or splatter. Lithium Battery Fires. Crew members should be trained not to treat a small number of lithium batteries as a Class D fire. Halon, Halon replacement, or water extinguishers can be used to control fires involving a small number of rechargeable lithium batteries as found in PED e.g. laptop computers, cell phones, pagers, audio/video/data recording or playback devices, messaging devices, PDAs, and two-way radios. Water or other water based liquid from any available source should be poured over the cells immediately after fire knockdown or extinguishment, since only water or water based liquids can provide sufficient cooling to prevent re-ignition and/or propagation of the fire to adjacent cells of the battery pack. A water extinguisher, by itself, can be used safely (from a distance) to extinguish a lithium battery fire and will usually cool it sufficiently to end the event. If needed, it can be followed up by water from any available source. (1) Crew members should be trained not to use fire resistant burn bags to isolate burning Lithium batteries. Transferring a burning appliance into a bur bag may be extremely hazardous. ### Page 19 (OCR) (2) See SAFO 09013 and the training video referred to in paragraph 1b above for further guidance on how to fight Lithium battery fires. 2. What are Some General Guidelines for the Safe-Use of Halocarbon Extinguishers? a. Quickly Extinguish the Fire. Although exposure to halocarbon agents and their decomposition products are a concern, it is far less of a concern than the consequences of an unextinguished in-flight fire. It is critically important to quickly extinguish an in-flight fire. The consequences of an unextinguished in-flight fire include the loss of the aircraft and its occupants and immediate toxic hazards from exposure to thermal decomposition products of the burning materials, including carbon monoxide, hydrogen cyanide, smoke, heat, and subsequent oxygen depletion. b. Control Exposure to Combustion Gases and Halocarbon Vapors. The following guidance is affected by and may be adjusted for agent stratification and localization, as discussed in chapter 4, paragraph 4b(4). (1) Turn off all air recirculation systems immediately, if allowed by your aircraft flight manual (AFM) or flight crew operations manual (FCOM). Halocarbon agents are much heavier than air and under most conditions they stratify with time at lower levels. Turning off the recirculation allows the agent entering the low level air returns to be directed to the air outflow valves and out of the aircraft. This increases the rate of agent removal from the aircraft. Some aircraft have up to 50% recirculation, so it is important to turn off the air recirculation quickly. (2) While it is impossible to accurately predict the hazard level in most situations, try to avoid selecting extinguishers that could result in exposure to halocarbon vapors above the safe-use levels. Exposure may result in dizziness, impaired coordination, reduced mental acuity, and heart arrhythmias. (3) Halocarbon agents also decompose when they contact open flames or hot surfaces. The decomposition products have a characteristic sharp, acrid odor, and an eye irritating effect, even in concentrations of only a few parts per million. See Annex A, Paragraph 1.5.1.2 and 5.7.1.2 of the standard in appendix 3, paragraph 11d of this AC, or the most current revision, for more detailed information on the effects of neat agent and hydrogen fluoride (HF) respectively, as well as further discussion of factors affecting the formation of thermal decomposition products. c. Use Portable Protective Breathing Equipment (PBE). In compartments where extinguisher(s) are used that do not meet the sate-use guidance in this AC, flight crewmembers should use portable PBE, if available and/or as directed by FCOM procedures or AFM. Unprotected personnel should not enter a protected space during or after agent discharge, until ventilated. Crewmembers should follow fire fighting procedures when using portable PBE. See paragraph 5b below for additional information on portable PBE use in cargo compartments. ### Page 20 (OCR) d. Ventilate the Compartment. (1) When you are reasonably sure the fire is extinguished, ventilate the compartment overboard at the highest possible rate allowed by established crew procedures for your particular aircraft to rid the cabin and flight deck of hazardous gases and smoke. Stay alert when increasing airflow, if the fire is not completely extinguished or smoldering, increasing airflow could promote fire growth. (2) Small aircraft lack some of the safety advantages available to large transport category aircraft. Large aircraft with small volume occupied spaces (flight decks) have a forced ventilation system, availability of supplemental oxygen (quick donning oxygen masks), and a copilot available. Therefore, operators of small unpressurized aircraft should open a window, if at all possible. 3. How to Prevent Hypoxia in an Unpressurized Aircraft. You can avoid life-threatening hypoxia (low oxygen) hazards that may result from the discharged halocarbon agent displacing air in unpressurized aircraft, by following the descent, ventilation, and supplemental oxygen guidance below. See the report referenced in appendix 3, paragraph 7m of this AC for information on the development of the guidance below. a. Extinguish Fire and Ventilate Cabin. As mentioned above, make sure the fire is completely extinguished. To rid the cabin and flight deck of hazardous gases and smoke, ventilate all unpressurized aircraft compartments overboard at the highest possible rate allowed by established crew procedures for your particular aircraft. If the fire is not completely extinguished, or a smoldering fire exists, increasing airflow could promote fire growth b. Descend to Lower Altitudes. Immediately descend at the maximum safe rate to 8,000 ft. or to an altitude that is as low as practicable. Descending dilutes agent concentration, lowers exposure to agent and combustion gases, and increases oxygen concentration. We recommend descending regardless of the amount of agent used, the aircraft size, or ventilation rate. Aircraft with a maximum flying altitude of 12,500 ft. are protected from hypoxia, without the need for supplemental oxygen, by immediately descending as described above. c. Use Supplemental Oxygen. Use of supplemental oxygen can prevent hypoxia. However, if a supplemental diluter demand personal oxygen system at CPAs above 12,500 ft., a nasal cannula up to and including 18,000 ft CPA, or an oral-nasal mask between 18,000 ft. and 25,000 ft. CPA are used, the user will not be fully protected from hypoxia. This lack of protection is because the oxygen flow control for these systems is based on pressure altitude, not oxygen partial pressure. (1) Occupants flying at altitudes above 12,500 ft. should immediately switch their masks or nasal cannula to the maximum flow of oxygen, if so equipped, to get additional protection during the time it would take to exchange the air in the compartment three times. ### Page 21 (OCR) (2) Fingertip probe oxygen sensors should be used with oxygen systems on unpressurized aircraft with maximum flying altitudes above 12,500 ft. These devices provide user feedback on the effects of hypoxia after halocarbon agent discharge such that the wearer can increase the oxygen flow to their breathing device to compensate for the hypoxia. (3) Unpressurized aircraft are allowed to use nasal cannula supplementary oxygen systems up to 18,000 ft. altitude. These systems provide no protection to a wearer when he or she breaths through the mouth, which can occur at times of stress. 4. What are the Guidelines on the Selection of Halocarbon Extinguishers? Extinguisher Performance. Primary consideration in selecting a fire extinguisher should be performance, size, and weight (see appendix 4, paragraph 3 of this AC), hardware configuration, extinguisher throw range (see appendix 4, paragraph 1 of this AC), ease of use for novices, commercial availability of the agent, and environmental issues (ODP and GWP). Special consideration needs to be made for cold temperature operation, as noted in chapter 3, paragraph 5b of this AC. Agent physical and chemical properties may also be considered. Toxicity/Human Exposure. As mentioned previously, human exposure to halocarbon agents is a concern and needs to be addressed as noted in paragraph 2b above. However, it is far less of a concern than the consequences of an unextinguished in-flight fire. From a hazardous exposure perspective, you may elect to select a halocarbon hand extinguisher using the safe-use W/V guidance (based on perfect mixing) described below for your specific compartment size. Safe-use W/V guidance provides an objective scientific evaluation of the currently approved agents. (1) The exposure hazard presented by the decomposition products of the agent may be considered when choosing a fire extinguisher for a particular installation. (2) Safe-use W/V guidance for various air change times, assuming perfect mixing, is presented in appendix 4, paragraph 2 of this AC. The methodology used to develop the safe-use W/Vs of halocarbon agents and their blends was developed in the report referenced in appendix 3, paragraph 7m of this AC. The safe-use W/V guidance is based on the discharge of the largest extinguisher in a compartment at 70° F at the aircraft certificated CPA. (3) These safe-use W/Vs may be used as general guidance and are based on perfect mixing gas concentration histories. This safe-use W/V guidance is not rigid, as there are many variables that can affect the agent concentration histories. Actual concentrations encountered by occupants may be significantly lower than would be encountered if there was perfect mixing depending on agent stratification, air distribution, air flow, and geometry of a particular aircraft/aircraft compartment and may be adjusted accordingly. Agent stratification/localization within a compartment, as mentioned in paragraph 4b(3) above, will be addressed in a report to be published at the FAA Technical Center. This report will provide limited examples and the method to properly adjust the safe-use concentrations for those examples. See appendix 4, paragraph 2a(4) 17 ### Page 22 (OCR) (5) For unpressurized aircraft, you should consider safe-use guidance for the highest altitude for which the aircraft is certified. (6) The cabin is considered and referred to as a compartment. The total charge weight of the largest extinguisher divided by the compartment volume should not exceed the safe-use W/V. (7) In a pressurized aircraft (6000 to 8,000 ft CPA), the hypoxic hazard is minimal for the safe-use concentrations for the halocarbon agents in this AC. Immediate descent is not necessary. Pressurized aircraft benefit (increased oxygen and decreased agent concentrations) only from descent to altitudes below the CPA. The worst case oxygen equivalent CPA for pressurized aircraft using the safe-use W/V guidance provided in this AC is 10,000 ft at 2 minutes after discharge when 8,000 ft CPA is maintained. However, landing as quickly as possible is always recommended when an onboard fire is suspected. c. Relative Agent Toxicity. You may want to consider the relative toxicity of extinguishers in Figure 1 below when selecting an extinguisher. Figure 1 shows the normalized toxicities of approved 5B:C extinguishers relative to the NOAEL-based toxicity of a 5B:C Halon 1211 extinguisher. These normalized toxicities are based on exposure to neat (un-decomposed) agent using 3 different measures: NOAEL, Safe Human Concentration and LOAEL. Figure 1. Relative Toxicity of 5 B:C Halocarbon Extinguishers 1.3 • NOAEL Basis 1 • Safe Human Concentration Toxicity of 5 B:C Extinguishers .9 Basis Relative to Halon 1211 • LOAEL Basis 2 0.0 Halon 1211 Halon 1301 HCFC Blend B HFC-227 ea HFC-236 Agent d. Minimum Safe Volume. Alternatively, you may consider minimum safe volumes to make your extinguisher selection. In this case, the minimum safe volume of one extinguisher is obtained by dividing that extinguisher's charge weight by the safe-use agent W/V for the appropriate altitude and ventilation (See appendix 4, paragraph 3 of this AC). ### Page 23 (OCR) 5. How to Safely Use Halocarbon Extinguishers in Accessible Cargo Compartments. a. Unsafe Concentrations of Extinguishing Agent. 14 CFR § 25.857 and § 29.855(d) require aircratt to be designed to prevent the harmful accumulation of smoke, flame, extinguishing agent and noxious gases from entering occupied areas. Airplane Flight Manual (AFM) fire fighting procedures should state that the crew member should close the Class B cargo compartment door after extinguishing a fire. When to Use Portable Protective Breathing Equipment (PBE). Portable PBE should be worn before entering the cargo compartment and attempting to extinguish a fire, as outlined in 14 CFR § 25.1439. Note that AFM and/or Crew Operations Manual are required to have the appropriate procedure including calling out the use of portable PBE and other emergency equipment necessary to fight a fire. Compartments Under 200 Cubic Feet. Halon replacement extinguishers should have a minimum fire rating classification of U.S. - UL 2A:10B:C for accessible Class B cargo compartments, combination passenger/cargo (combi) and cargo airplane/rotorcraft. The fire threat for accessible cargo compartments is primarily from Class A fires. Usually, one extinguisher with a U.S. - UL 2A: 10B:C rating is sufficient to fight most fires likely to occur. (1) Multiple hand-held fire extinguishers may be shared to comply with the cabin and accessible Class B cargo compartment regulations, if they are located where a person fighting a fire in the compartment could quickly retrieve them and continue fighting the fire with minimal delay between the discharges. It must be demonstrated that the extinguishers, as installed, can extinguish 2A and 10B:C rated fires. The combined rating is to be determined by performing the UL 711 fire tests by discharging the extinguishers with a delay between the end of each extinguisher's discharge and the start of the discharge of the next extinguisher based on the location of each extinguisher and an assessment of factors such as: (a) The manpower available to fight the fire. If two trained crew members are available to fight the fire, it may be possible to avoid a delay between discharges of the extinguishers. (b) The time to recognize the completion of the discharge, to walk to the location of the next bottle, remove it from it's mounting bracket, pull the pin, return to the cargo compartment, position the extinguisher to continue to fight the fire and initiate discharge. (2) The rating is based on UL 711 performance tests, not agent weight, as the agent weight is not sufficient to predict performance. Nozzle design, super pressurization and other factors affect performance. The UL fire tests can be preformed by the applicant or an approved test laboratory such as UL. ### Page 24 (OCR) Note: The recommended extinguisher rating of 2A: 10B:C is lower than the 2A:40B:C rating in AC 20-42C. This is because the fire threat for accessible cargo compartments is primarily from Class A fires. The prior guidance in AC 20-42C was based on the need for at least a 2A rating for class A fires using a Halon 1211 extinguisher to extinguish a fire. Halon 1211 extinguishers that have a class A rating of 2A also have a 40B:C rating. It has been determined that a 10B:C rating is more then adequate for the type and size of class B and C fires likely to occur in a Class B cargo compartment. Compartments Over 200 Cubic Feet. Accessible cargo compartments of 200 ft3 and larger, in combination passenger/cargo and cargo aircraft/rotorcraft, should comply with the requirements of the FAA Airworthiness Directive (AD) 93-07-15. This AD specifies acceptable forms of fire protection equipment and operational procedures. The options provided include converting the compartment to meet the requirements of a Class C cargo compartment, use of hand-held fire extinguishers, or the use of fire containment containers or covers, fire extinguishing systems and smoke or fire detectors. (1) If you elect to use hand fire extinguishers provide the following: (a) A minimum of three U.S. - UL listed Halon 1211 or its equivalent 2A: 10B:C hand held fire extinguishers (equivalent to the AD's requirement of 48 Ibs. of Halon 1211) readily available for use in the cargo compartment. (b) At least two U.S. - UL 2A (2-1/2 gallon) listed water portable fire extinguishers, usually TSO C19 or its equivalent, adjacent to the cargo compartment entrance for use in the compartment. (c) Protective garments stored adjacent to the cargo compartment entrance. (d) Portable PBE with a minimum of 15 minutes of protective breathing, per 14 CFR § 25.1439(b)(5). This portable PBE should be TSO C116 approved or equivalent, and be stored adjacent to the cargo compartment entrance. (2) If no extinguisher is available that meets the safe-use criteria for the aircraft/rotorcraft cabin, consider converting that cargo compartment to a class C compartment with a built-in fire suppression system, or any other technology that would provide effective fire protection. Restrict personnel from entering the cargo compartment for the duration of the flight. How to Inspect and Maintain the Hand Fire Extinguisher for Continued Safe-Use. Maintain and inspect hand fire extinguishers in accordance with the manufacturer's nameplate instructions. Follow the maintenance procedures, inspections and testing specified in the applicable NFPA and U.S. - UL standards. ### Page 25 (OCR) a. Non-refillable, disposable fire extinguishers may have plastic discharge heads installed. Locate this type of fire extinguisher in a safe area to assure there will be no damage to the plastic discharge heads. b. Non-refillable, disposable fire extinguishers are exempt from periodic hydrostatic testing. However, replace these extinguishers with a serviceable unit upon reaching: (1) The service life where hydrostatic testing would normally be required for a similar extinguisher, or (2) The service life guidelines established by the manufacturer if sooner. c. Recommended procedures for the inspection, hydrostatic test and life limits of pressure cylinders are outlined in: (1) Specification of cylinders is in 49 CFR, part 178, subpart C. (2) Inspection and maintenance of cylinders is in 49 CFR, part 180, subpart B. (3) Fire extinguishers are addressed in 49 CFR § 173.309 and in 29 CFR § 1910.157. d. Manufacturers of fire extinguishers containing halon replacement agents approved for use on FAA certified aircraft should take immediate action through the appropriate channel(s) to have their retest requirements included in the aforementioned regulatory guidelines. ### Page 26 (OCR) Chapter 5. Locating and Mounting Hand Fire Extinguishers Where to Locate and Mount Hand Fire Extinguishers in Passenger Compartments. Install fire extinguishers in passenger compartments according to 14 CFR §§ 23.851, 25.851, and 29.853 and the following criteria: a. Locate hand fire extinguishers adjacent to hazardous areas (for example, galleys, accessible baggage or cargo compartments, electrical equipment racks, etc.) to be protected. b. If there are no defined hazardous areas, locate the hand fire extinguishers as follows: () When one extinguisher is used, locate it at the flight attendant's station. (2) When no flight attendant is required, locate the extinguisher at the passenger entrance door. (3) When two or more extinguishers are used, locate one at each end of the passenger compartment and space the remainder uniformly within the cabin area. C. Mount hand fire extinguishers for ready accessibility. It they are not visible in their mounted position, use a placard to indicate their location. (1) Aircraft structure and mounting brackets are required to withstand the applicable inertia forces required in 14 CFR §§ 23.561, 25.561, 27.561, and 29.561, with the hand fire extinguisher installed. Replacement of halon extinguishers with halocarbon extinguishers will require an evaluation of the mounting system strength. The mounting structure may need to be strengthened. Halocarbon clean agent extinguishers of the same listing can be 2-3 times the weight of the halon extinguishers they are replacing. (2) For large transport category aircraft, installation of an extinguisher should include vertical reach combined with horizontal (offset) reach to ensure ease of retrieval from overhead compartments. The vertical reach should not exceed 74.5 in. (189.23 cm) combined with an offset reach of 7.87 in. (20cm) to permit a 5 percentile female, 60.5 in. (153.67 cm.) tall to quickly access the extinguisher. Consideration should be allowed for assist steps (or seats) or other factors. (3) Add the weight of the hand fire extinguisher and its mounting bracket to the aircraft empty weight and a compute a new empty weight center of gravity. Consider the type of fire hazard (Class A, B, CorD) expected to be encountered when you select a hand fire extinguisher. If extinguishers intended for different classes of fire are grouped together, consider marking their intended use conspicuously via a placard or other means (near the extinguisher) to aid in the choice of the proper extinguisher at the time of the fire. ### Page 27 (OCR) 2. How to Locate and Mount Hand Fire Extinguishers in Flight Deck Compartments. Consider using the following criteria if you install a fire extinguisher in the flight deck compartment: a. Each hand fire extinguisher should be conveniently located, readily accessible, and it's location obvious. b. Hand fire extinguishers should be mounted for easy release and removal. For aircraft designed for single pilot operation, the hand fire extinguisher should be located for release and removal by the pilot in the seated position. (1) Secure the extinguisher(s) in mounting brackets) such that it requires a deliberate action to release the extinguisher from its primary restraint for removal from its mounting. Design the mounting bracket so that upon release from their primary restraint, the extinguisher remains in position until removed from its mounting by the user. (2) Aircraft structure and extinguisher mounting brackets must be capable of withstanding the inertia forces specified in paragraph 1c above. c. Fire extinguishers for the flight deck compartment should be able to extinguish Class B and C fires. 3. How to Locate and Mount Hand Fire Extinguishers in Small Single Engine and Multiengine Aircraft. a. Locate hand fire extinguishers so that they are easily accessible to the flight crew and the passengers. b. Do not allow hand fire extinguishers to lie loose on shelves, seat back pockets or seats. Properly mount the hand fire extinguisher to the airframe structure. c. Aircraft structure and extinguisher mounting brackets should be capable of withstanding the inertia forces specified in paragraph 1c above. 4. How Many Hand Extinguishers Must I Install? a. Transport Category Airplanes. 14 CFR §§ 25.851(a) and 121.309(c) requires a minimum number of hand extinguishers to be installed on transport category airplanes. (1) The minimum number of hand fire extinguishers that must be conveniently located and evenly distributed in passenger compartments are as shown in Figure 2 below. ### Page 28 (OCR) Figure 2. Minimum Number of Hand Fire Extinguishers Required for Transport Category Aircraft Passenger Compartments Passenger No. of Capacity Extinguishers 7 through 30 31 through 60 2 61 through 200 3 201 through 300 4 301 through 400 5 401 through 500 6 501 through 600 7 601 through 700 8 (2) At least one hand fire extinguisher must be conveniently located in the pilot compartment. (3) At least one readily accessible hand fire extinguisher must be available for use in each Class A or Class B cargo or baggage compartment and in each Class E cargo or baggage compartment that is accessible to crewmembers in flight, per 14 CFR § 25.851(a)(3). (4) At least one of the required fire extinguishers located in the passenger compartment of an airplane with a passenger capacity of at least 31 and not more than 60, and at least two of the fire extinguishers located in the passenger compartment of an airplane with a passenger capacity of 61 or more must contain Halon 1211, or equivalent, as the extinguishing agent. (5) The quantity of extinguishing agent used in each extinguisher required by this section must be appropriate for the kinds of fires likely to occur where used. b. Transport Category Rotorcraft. Title 14 CFR § 29.853 requires a minimum number of hand extinguishers to be installed in passenger compartments: (1) See Figure 3 below for the minimum number of hand fire extinguishers that must be conveniently located in passenger compartments. ### Page 29 (OCR) Figure 3. Minimum Number of Hand Fire Extinguishers Required for Transport Category Rotorcraft Passenger Compartments Passenger No. of Capacity Extinguishers 7 through 30 31 through 60 2 61 or more 3 (2) There must be a hand fire extinguisher for the flight crewmembers. (3) There are no requirements for extinguishing systems or hand extinguishers for accessible cargo or baggage compartments in transport category rotorcraft. Use the hand extinguisher guidance provided in chapter 4, paragraph 6 of this AC for these compartments. c. Small Airplanes. Title 14 CFR §§ 23.851 and 91.513(c) requires a minimum number of hand extinguishers to be installed on small part 23 airplanes. (1) At least one hand fire extinguisher must be located within easy access of the seated pilot. (2) At least one hand fire extinguisher must be in the passenger compartment of an airplane that accommodates more than six passengers. The extinguisher must minimize the hazard of toxic gas concentration. ### Page 30 (OCR) Appendix 1 Appendix 1. List of Acronyms 14 CFR Title 14, Code of Federal Regulations Advisory Circular ACO Aircraft Certification Office AD Airworthiness Directive AFM Airplane Flight Manual American Society of Testing and Materials Civil Aviation Authority Code of Federal Regulations Cabin Pressure Altitude Department of Transportation U.S. Environmental Protection Agency FAA Federal Aviation Administration FAATC FAA Technical Center FC Fluorocarbon FCOM Flight Crew Operations Manual FIC Fluoroiodocarbon FK Fluoroketone FM Factory Mutual Research Corp. HCFC Hydrochlorofluorocarbon HF Hydrogen Flouride HFC Hydrotluorocarbon ICA Instructions for Continued Airworthiness ISO International Organization for Standardization LOAEL Lowest Observable Adverse Effect Level MF Multiplication Factor MPS Minimum Performance Standard No Observable Adverse Effect Level National Fire Protection Association Perfluorocarbon Protective Breathing Equipment Physiologically Based Pharmacokinetic Personal Digital Assistant Portable Electronic Device Regulatory Guidance Library Radio Technical Corporation of America Society of Automotive Engineers Significant New Alternatives Policy Air Change Time Technical Standard Order Underwriters Laboratories United States Coast Guard W/V Weight per Unit Volume (W/V) Ratio %V/V Volume Percent A1-1 ### Page 31 (OCR) Appendix 2 Appendix 2. Definitions and Terms The following definitions and terms apply when following the procedures outlined in this AC: 1. Air Change Time. t. is the time in minutes, it takes for the inflow of fresh air into a compartment, with a volume equivalent to the volume of the compartment. 2. Cabin Pressure Altitude is specified for transport aircraft by regulation to be the air pressure in the cabin or compartment of a commercial airliner and it must not be lower than that found at an altitude of 8,000 ft (2,438 m) under normal operating conditions, per § 25.841(a) Cargo Aircraft are aircraft configured solely to carry cargo and no personnel other than the flight crew and any additional crew required for the care of the cargo. 4. Clean Agent is electrically nonconducting, volatile or gaseous fire extinguishant that does not leave a residue upon evaporation. The word agent as used in this circular means clean agent unless otherwise indicated. 5. Combi Aircraft are designed/configured to transport both passengers and cargo on the same level within the fuselage. 6. Compartment is an enclosed space on an aircraft. Examples of compartments are a flight deck, a crew rest, and a cabin. The aircraft cabin is considered one compartment. 7. Dry Chemical is a mixture of finely divided solid particles, usually sodium bicarbonate, potassium bicarbonate, or ammonium phosphate-based with added particulate material supplemented by special treatment to provide resistance to packing, and moisture absorption (caking) and to promote proper flow characteristics. Dry Powder is solid materials in powder granular form designed to extinguish class D combustible metal fires by crusting, smothering, or heat transferring means. 9. Flight Crew are responsible for the operation and management of the aircraft flight controls, engines, and systems, including, but not limited to, pilot in command (captain), first officer (copilot), second officer (flight engineer). 10. Flight Deck is the compartment of the aircraft arranged for use by the flight crew in operating the aircraft. 11. Galley is the area of the aircraft for storing, refrigerating, heating and dispensing of food and beverages. A2-1 ### Page 32 (OCR) 10/XX/10 AC 20-42D Appendix 2 12. Halocarbon Agent is comprised primarily of one or more organic compounds containing one or more of the elements fluorine, chlorine, bromine, or iodine. Halocarbon agents are electrically non-conducting, volatile liquids, or gaseous fire extinguishants. As "clean agents", they do not leave a residue on evaporation. Halocarbon agents (halons and halon replacements) that are currently commercialized include the hydrochlorofluorocarbons (HCFCS), perfluorocarbons (FCs or PFCs), hydrofluorocarbons (HFCs), fluoroiodocarbons (FICs), and fluoroketones (FKs), as well as the completely halogenated halocarbons (halons). Halocarbon agents are multipurpose class A, B, Crated agents and are most effective on Class B and C fires. Advantages of halocarbon agents include low cold shock characteristics on electronic equipment, no degradation of visual acuity, and low pressure. 13. Halocarbon Blend is a mixture of 2 or more halocarbon agents in a portable extinguisher. 14. Halon is a short derivation for "halogenated hydrocarbon." The chemical structure is identified as a four digit number representing, respectively, the number of carbon, fluorine, chlorine, and bromine atoms present in one molecule. Both Halon 1211 and Halon 1301 are liquefied gases and typified as "clean agents." Halons primarily extinguish fire by chemically interrupting the combustion chain reaction rather than by heat removal or physically smothering. 15. Halon Equivalent Extinguisher is an extinguisher containing a clean agent which meets the MPS for hand-held fire extinguishers (see appendix 3 reference paragraph 7s of this AC). Equivalency does not refer to agent weight, but the effectiveness of extinguishing a fire. Halon replacement extinguishers may be more than twice the weight of halon extinguishers. 16. Halon 1211 has the chemical name bromochlorodifluoromethane, CBrC1F2. Halon 1211 is a multipurpose, Class A, B, C rated agent effective against flammable liquid fires. Due to its relatively high boiling point of +26°F (-4°C). Halon 1211 discharges as an 85 percent liquid stream offering a long agent throw range. 17. Halon 1301 has the chemical name bromotrifluoromethane, CBrF3. Halon 1301 is recognized as a multipurpose agent having Class A, B, C capability in total flooding systems. However, Halon 1301 offers limited Class A capability when used in portable fire extinguishers. The boiling point for this agent is -72°F (-57.8°C). Halon 1301 discharges as a gas. 18. Halon Replacement Agents are any clean agents which can be either a non-halon (halocarbon agent) or halon alternative (all other substitute agents) that have SNAP approval by the U.S. EPA and meet the MPS for hand fire extinguishers. 19. Hand Fire Extinguisher is an approved, aircraft portable fire extinguisher which can be used by aircraft occupants to combat accessible, incipient, on-board fires. 21. HFC-227ea is an extinguishing agent that is comprised of the chemical 1,1,1,2,3,3,3- heptatluoropropane (CF CHFCF3). The boiling point of the agent is 2.5°F (-16.4°C). Due to this boiling point, HFC-227ea is discharged as a mixed liquid and vapor stream which readily evaporates. It is a multipurpose agent with class A, B and C capability. A2-2 ### Page 33 (OCR) Appendix 2 22. HFC-236fa is an extinguishing agent that is comprised of the chemical 1,1,1,3,3,3 hexafluoropropane (CF3CH,CF3). The boiling point of the agent is +29.5°F (-1.4°C). Due to its relatively high boiling point, HFC-236fa discharges predominately as a liquid stream which readily evaporates. It is a multipurpose agent with class A, B and C capability. 23. HCFC Blend B is an extinguishing agent that is a tertiary blend comprised primarily of the chemical 2,2-dichloro-1,1,1-trifluoroethane HCFC-123, (CFCHCI). Two inert gases are blended with the HCFC-123 to enhance flow distribution and fire extinguishing performance. The boiling point of the blend is 80.6°F (27°C). Due to its high boiling point, HCFC Blend B discharges primarily as a liquid stream which readily evaporates. It is a multipurpose agent with class A, B, and C capability. 24. Labeled equipment or materials have an attached label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner. 25. Listed refers to equipment, materials or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services. The organization maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and who's listing states that the equipment, material or service meets appropriate designated standards or has been tested and found suitable for a specified purpose. 26. Listing Mark is a certification mark allowed to be carried as a stamp of approval by nationally recognized standards/testing organization. 27. Lithium Ion Battery is a rechargeable battery that has an anode made from a metal oxide composite containing lithium ion, and a cathode made from a specialized carbon material. Charge and discharge of the battery is facilitated by the movement of lithium ions in electrolytic solutions. Lithium ion batteries are used in small electronic devices such as pagers, portable computers, camcorders, and portable telephones. 28. Lithium Primary Battery is a rechargeable battery that has a lithium anode and a cathode system consisting of carbon and either thionyl chloride or sulfuryl chloride. 29. Lowest Observable Adverse Effect Level (LOAEL) is the lowest concentration at which an adverse physiological or toxicological effect has been observed in dogs. 30. Maximum Certificated Occupant Capacity is the maximum number of persons that can be carried for each specific aircraft model as certified by the authority having jurisdiction. A2-3 ### Page 34 (OCR) Appendix 2 31. Minimum Performance Standard (MPS) for Hand Extinguishers refers specifically to two tests that hand extinguishers containing halon replacement agents must pass. See appendix 3 reference paragraph 7s. These fire tests demonstrate equivalent fire extinguishing performance currently used in aircraft and assess the toxicity of the decomposition products. 32. Minimum Safe Volume refers to the smallest compartment volume into which one extinguisher could be discharged, assuming perfect mixing of agent, without posing a toxicity hazard. Minimum safe volumes are dependent on the agent, the agent weight, ventilation, and pressure altitude of the discharge. 33. Neat in this context refers to un-decomposed agent. 34. No Observable Adverse Effect Level (NOAEL) is the highest concentration at which no adverse physiological or toxicological effect has been observed in dogs. 35. Physiologically Based Pharmacokinetic (PBPK) Model is a mathematical model for human health risk assessment and investigation of toxicity. The health concern for halocarbons, including halons, is cardiac sensitization which occurs at a fixed target arterial concentration. The model estimates the allowable arterial blood concentration as a function of agent exposure time to establish both the concentration of agent and duration to which personnel could be safely exposed. The PPK modeling is endorsed by the U.S. EPA and the NFPA. 36. Rated/Rating is a numerical value assigned to an extinguisher based on its fire extinguishing capability. 37. Safe Human Exposure Concentrations are based on PPK modeling. Safe human concentrations are exceeded when the simulated arterial concentration exceeds the target arterial concentration. 38. Small Aircraft are defined by part 23. 39. SNAP Program is EPA's significant new alternatives policy (SNAP) program to evaluate and regulate substitutes for ozone depleting chemicals that are being phased out under the stratospheric ozone protection provisions of the Clean Air Act. 40. Time of Useful Consciousness is the time available to don an oxygen mask without assistance. 41. Unventilated Compartment for the purposes of the AC is a compartment where the air change time is not known or exceeds 6 minutes. 42. Ventilated Compartment is a compartment where the air change time is known and does not exceed 6 minutes. 43. Volume Percent (% v/v) is the gas volume in liters per 100 liters of the resulting gas mixture, e.g. 2% v/v Halon 1211 mixture contains 2 liters Halon 1211 per 100 liters volume. A2-4 ### Page 35 (OCR) Appendix 3 Appendix 3. Related Publications and How to Get Them Code of Federal Regulations (CFR). You can get copies of Title 14, 40, 46, and 49 of the Code of Federal Regulations, parts from the Superintendent of Documents, Government Printing Office, P.O. Box 37154, Pittsburgh, PA 15250-7954. Telephone (202) 512-1800; fax (202) 512- 2250. You can order copies Title 14 through the FAA website at http://rgl.faa.gov/. Select "Access" then "Online Bookstore." Select "Aviation," then "Code of Federal Regulations." You can also get copies of 14 CFR sections on-line at www.gpoaccess.gov/cfr/ and copies of 40 CFR sections on-line at www.epa.gov/epahome/cfr40.htm. The following is a list of applicable Federal Regulations used for this AC: 14 CFR §§ 21.305, 23.561, 23.851, 23.1441, 23.1443-1449, 25.561, 25.851, 25.857, 25.1439, 27.561, 27.861, 29.561, 29.851, 29.853(e) and (t), 91.122, 91.211, 91.193, 121.309(c), 125.119(b) and (c), 127.107(c), 135.155. b. Title 40 of the Code of Federal Regulations (40 CFR), Chapter I--Environmental Protection Agency, part 82-Protection of Stratospheric Ozone, subpart G-Significant New Alternatives Policy Program and subpart H-Halon Emissions Reduction (40 CFR part 82). Title 46 of the Code of Federal Regulations (46 CFR), Chapter I-Coast Guard, Department of Transportation, part 34-Fire Fighting Equipment. d. Title 49 of the Code of Federal Regulations (49 CFR), Transportation. 2. FAA Airworthiness Directive (AD). You can get copies of the following AD from the FAA's website at www.airweb.faa.gov/rgl. a. AD 93-07-15, Boeing And McDonnell Douglas Models 707, 727, 737,747, and 757 and McDonnell Douglas Models DC-8, DC-9, and DC-10 Series Airplanes 3. FAA Advisory Circulars (AC). Order copies of Advisory Circulars (AC) from the U.S. Department of Transportation, Subsequent Distribution Office, M-30, Ardmore East Business Center, 3341 Q 75th Avenue, Landover, MD 20795. Telephone (301) 322-5377, fax (301) 386- 5394. To be placed on FAA's mailing list for free ACs contact, U.S. Department of Transportation, Distribution Requirements, Section, M-494.1, Washington, D.C, 20590. You can also get copies at www.airweb.faa.gov/rgl. On the website, select "Advisory Circulars," then select "By Number." a. AC 120-80, In-Flight Fires b. AC 20-42C, Hand Fire Extinguishers for Use in Aircraft c. AC 25-17, Transport Airplane Cabin Interiors Crashworthiness Handbook d. AC 25-18, Transport Category Airplanes Modified for Cargo Service A3-1 ### Page 36 (OCR) Appendix 3 e. AC 25-22, Certification of Transport Airplane Mechanical Systems f. AC 25-869-1, Fire Protection Systems g. AC 65-9A, [Large AC] Airframe and Powerplant Mechanics General Handbook h. AC 65-12A, [Large AC] Airframe and Powerplant Mechanics Powerplant Handbook 4. FAA Technical Standard Order (TSO). You can find the following technical standard orders on the FAA website at http://rgl.faa.gov/ or at www.airweb.faa.gov/rgl. You will also find the TSO Index of Articles at the same site. a. TSO-C19, Portable Water-Solution Type Fire Extinguisher b. TSO-C116, Crewmember Portable Protective Breathing Equipment 5. FAA Safety Alerts for Operators (SAFOS) and Information for Operators (InFOs) a. SAFO 09013 Fighting Fires Caused by Lithium Type Batteries in Portable Electronic Devices, June 23, 2009, www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all safos/media/ 2009/SAFO09013.pdf b. InFO 09010 Availability of a Federal Aviation Administration (FAA) In-flight Firefighting Training Video, June 23, 2009, www.faa.gov/other visit/aviation_industry/airline_operators/airline_safety/info/all infos/media/ 2009/info09010.pdf 6. FAA Training Videos: a. "Extinguishing In-flight Laptop Computer Fires" and "Cabin Crew Firefighting Training Video," a training video on the use of hand extinguishers to fight on-board fires are available for viewing at www.fire.tc.faa.gov/2007Conference/session details.asp?sessionlD=26 Reports and Papers. Order copies of the following reports and papers from the National Technical Information Service, Springfield, Va. 22161. FAA publications can also be found on the following Web Site of the FAA Fire Safety Branch: http://www.fire.tc.faa.gov/reports/reports.asp. Journal articles can be obtained directly from the publisher. Printed copies of Civil Aviation Authority documents are available from Documedia Solutions Ltd., 37 Windsor Street, Cheltenham, Glos., GL522DG, United Kingdom. a. Abramowitz, A., Neese, W., Slusher, G, Smoke and Extinguisher Agent Dissipation in a Small Pressurized Fuselage, Federal Aviation Administration, Report No. DOT/FAA/CT- 89/31, 1990. A3-2 ### Page 37 (OCR) Appendix 3 b. Blake, D.R., Effectiveness of Flight Attendants Attempting to Extinguish Fires in an Accessible Cargo Compartment, Federal Aviation Administration Technical Note DOT/FAA/AR-TN99/29, 1999. Chattaway,A., The Development of A Hidden Fire Test for Aircraft Hand Extinguisher Applications, Civil Aviation Authority Paper No. 95013, London, 1995. d. Cherry, R.G. W. et al, A benefit Analysis for Enhanced Protection from Fires in Hidden Areas on Transport Aircraft, Federal Aviation Administration Report No. DOT/FAA/AR-02/50, CAA Paper 2002/01. e. Colton, B., Gargas, M., Sweeney, L.,Setting Acute Exposure Limits for the Halotron 1 Clean Agent Onboard Aircraft Using Physiologically Based Pharmacokinetic Modeling, Submitted to Louise Speitel, Federal Aviation Administration, July 16, 2008. 1. Eklund. Thor I., Analysis of Dissipation of Gaseous Extinguishing Agents in Ventilated Compartments, Federal Aviation Administration Report No. DOT/FAA/CT-83/1, 1993. Hill, R.G., and Speitel, L., In-Flight Aircraft Seat Fire Extinguishing Tests (Cabin Hazard Measurement, Federal Aviation Administration Report No. DOT/FAA/CT-82/111, December 1982. h. Krasner, L.M., Study of Hand-held Fire Extinguishers aboard Civil Aviation Aircraft, Factory Mutual Research Corporation, Federal Aviation Administration Report No. **DOT/FAA/CT-82/42, 1982.** Lain, M.J.,Teagle, D.A., Cullen, J., Dass, V., Dealing with In-Flight Lithium Battery Fires in Portable Electronic Devices, Civil Aviation Authority Paper No. 2003/4, London, 2003, ©Civil Aviation Authority 2003. Slusher, G.R., Wright, J.A., and Speitel, L.C., Halon Extinguishment of Small Aircraft Instrument Panel Fires, DOT/FAA/CT-86/26, December 1986. k. Slusher, Gerald R., Wright, Joseph, Demaree, James, Halon Extinguisher Agent Behavior in a Ventilated Small Aircraft, Federal Aviation Administration Report No. **DOT/FAA/CT-86/5, 1986.** 1. Slusher, G.R., Wright, J., Demaree, J.E., Neese, W.E., Extinguisher Agent Behavior in a Vantilated Small Aircraft, Federal Aviation Administration Report No. DOT/FAA/CT- 83/30, 1984. m. Speitel, Louise C., Lyon, Richard E., Guidelines for Safe Use of Gaseous Halocarbon Extinguishing Agents in Aircraft, Federal Aviation Administration: Report No. DOT/FAA/AR- 08/3. A3-3 ### Page 38 (OCR) Appendix 3 n. Tabscott, R.E. and Speitel, L.C. eds., "Options to the Use of Halons for Aircraft Fire Protection Systems- 2002 Update", Federal Aviation Administration Report No. DOT/FAA/AR- 99/63, Task Group on Halon Options, International Halon Replacement Working Group, U.S. Department of Transportation, FAA William J. Hughes Technical Center, February, 2002. O. Vinegar, A., Jepson, G.W. and Overton, J.H (1998), PPK Modeling of Short-term (0-5 min) Human Inhalation Exposures to Halogenated Hydrocarbons, Inhalation Toxicology, 10:411-429. Vinegar, A., Jepson, G.W., Cisneros, M., Rubenstein, R. and Brock, W.J. (2000), Setting Safe Acute Exposure Limits for Halon Replacement Chemicals Using Physiologically Based Pharmacokinetic Modeling, Inhalation Toxicology, 12:751-763. Vinegar, A (2001), Modeling Cardiac Sensitization Potential of Humans Exposed to Halon 1301 or Halon 1211 Aboard Aircraft, Aviation, Space and Environmental Medicine, Vol. 72, No. 10. Vinegar, A., Jepson, G.W., Hammann, S.J., Harper, G., Dierdorf, D.S. and Overton, J.H.(1999), Simulated Blood Levels of CF3l in Personnel Exposed During Its Release from an F-15 Jet Engine Nacelle and During Intentional Inhalation, AIHA Journal, 60:403-408. S. Webster, Harry, Development of a Minimum Performance Standard (MPS) for Hand- Held Fire Extinguishers as a replacement for Halon 1211 on Civilian Transport Category Aircraft, Federal Aviation Administration Report No. DOT/FAA/AR-01/37, 2002. Webster, Harry, Flammability Assessment of Bulk-Packed, Nonchargeable, Lithium Primary Batteries in Transport Category Aircrafi, Federal Aviation Administration Report No. **DOT/FAA/AR-04/26, 2004.** Webster, Harry, Flammability Assessment of Bulk-Packed, Rechargeable, Lithium- Ion Cells in Transport Category Aircraft, Federal Aviation Administration Report No. **DOT/FAA/AR-06/38, 2006.** 8. American Society of Testing and Materials (ASTM) Standards. You can get copies of the tollowing ASIM standards from ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Telephone (610) 832-9585. You can also order on-line at www.astm.org, or contact ASTM Customer Service at service@astm.org. a. ASTM D7673-10, Standard Specification for Halon 1211. Bromochlorodifluoromethane (CF2CIBr) b. ASTM D5632-08, Standard Specification for Halon 1301, Bromotrifluoromethane c. ASTM D5631-08, Standard Practice for Handling, Transportation and Storage of Halon 1301, Bromotrifluoromethane (CF 3Br) A3-4 ### Page 39 (OCR) Appendix 3 d. ASTM D 7122-05, Standard Specification for HCFC Blend B (CFCCIH, Ar, and CFa e. ASTM D 7123-04, Standard Practice for Handling, Transportation, and Storage of HCFC Blend B (CFCCIH, Ar, and CF4) f. ASTM 6064-03, Standard Specification for HFC-227ea 1,1,1,2,3,3,3- Heptafluoropropane (CFSCHFCFs) g. ASTM D6065-05, Standard Practice for Handling, Transportation, and Storage of HFC-227ea 1,1,1,2,3,3,3-Heptafluoropropane (CFCHFCFs) h. ASTM D6541-05, Standard Specification for HFC-236fa. 1,1,1,3,3,3- Hexafluoropropane (CFCH CF 3) i. ASTM D6427-04, Standard Practice for Handling, Transportation, and Storage of HFC-236fa, 1,1,1,3,3,3-Hexafluoropropane (CF3CH,CF3) 9. Factory Mutual Research Corp. (FM). Order copies of the FM approval standards from FM Corporate Headquarters 1151 Boston-Providence Turnpike, P.O. Box 9102, Norwood, MA 02062 USA. Telephone +1-781-762-4300. You can also order on-line at www.fimglobal.com: 10. International Organization for Standardization (ISO). Order copies of the following ISO standards from ISO, 1, rue de Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland. Telephone +41-22-749-01-11. You can also order on-line at www.iso.org: a. ISO 7201-1:1989, Fire Protection -- Fire Extinguishing Media - Halogenated Hydrocarbons -- Part 1: Specifications for Halon 1211 and Halon 1301. 11. National Fire Protection Association (NFPA). Order copies of the following NFPA standards from NFPA, 1 Batterymarch Park, Quincy, MA 02169-7471. Telephone +1 800 344- 3555 or +1 617 770-3000. You can also order on-line at www.nfpa.org: a. NFPA 10, Standard for Portable Fire Extinguishers, 2007 Edition b. NFPA 12A, Standard on Halon 1301 Fire Extinguishing Systems, 2009 Edition c. NEPA 12B, Standard on Halon 1211 Fire Extinguishing Systems, 1990 Edition (No longer an active standard) d. NEPA 2001, Standard on Clean Agent Fire Extinguishing Systems, 2008 Edition A3-5 ### Page 40 (OCR) Appendix 3 12. RTCA Inc. Documents. Order copies of the following RTCA Inc. documents from RTCA Inc., 1828 L Street NW., Suite 805, Washington, D.C. 20036. Telephone (202) 833-9339, fax (202) 833-9434. You can also order copies online at www.rtca.org. a. RTCA/DO-160F, Environmental Conditions and Test Procedures for Airborne Equipment 13. SAE Documents. Order copies of SAE Aerospace Standards from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001. Telephone (724) 776-4970, fax (724) 776-0790. You can also order copies online at www.sac.org. 14. Underwriters Laboratories, Ine (UL). You can get copies of the following U.S. - UL standards from UL Corporate Headquarters, 333 Pfingsten Road, Northbrook, IL 60062-2096 USA. Telephone Customer Service +1-877-ULHELPS (1-877-854-3577). You can also order a. U.S. - UL 154, Carbon-Dioxide Fire Extinguishers (Ninth Edition), April20, 2009. b. U.S. - UL 299, Dry Chemical Fire Extinguishers (Tenth Edition), April 20, 2009. c. U.S. - UL 626, Water Fire Extinguishers (Eighth Edition), January 31, 2007. d. U.S. - UL 711, Rating and Fire Testing of Fire Extinguishers (Seventh Edition), April 13, 2009. e. U.S. - UL 1093, Standard for Halogenated Agent Fire Extinguishers (Fifth Edition), November 30, 1995. (UL intends to withdraw this standard effective October 2014) 1. U.S. - UL 2129, Halocarbon Clean Agent Fire Extinguishers (Second Edition), January 31, 2007. A3-6 ### Page 41 (OCR) Appendix 4 Appendix 4. Explanatory Material 1. Effective Throw Ranges. Typical throw ranges for halocarbon and water extinguishers are listed in Figure 4 below. Figure 4. Effective Throw Ranges for Halocarbon Halon Replacement and Water Extinguishers Effective Throw Ranges for UL/ULC Agent Rated Extinguishers*,° (ft.) 2-B:C 5-B:C 1A-10B:C 2A-10B:C 2A-40B:C HCFC Blend B 6-10 9-15 9-15 N/A 12-18 N/A HFC-236fa 8-10 10-12 14-16 N/A 14-16 N/A HFC-227ea N/A 8-10 N/A N/A N/A N/A Halon 1211 9-12 9-15 12-18 N/A N/A 12-18 Halon 1301 N/A N/A N/A N/A N/A NIA Water© N/A N/A N/A 45-55 N/A N/A a Throw range is extinguisher dependant and may differ from tabulated values. b Check the manufacturer's literature for the throw ranges of their extinguishers. c Initial Throw Range 2. Safe-Use Guidance. The toxicity guidance for the inhalation of halocarbon vapors is conservative. The development of this guidance can be found in the report referenced in appendix 3, paragraph 7m of this AC. The methodology used applies pharmacokinetic (PBPK) modeling of canine blood concentration data to perfect mixing agent decay curves. A particular PBPK model and target arterial concentration was used, as outlined in Section 4.1.2 of the aforementioned report. It assumes a compartment temperature of 70° F (21°C) at the stated pressure altitude, perfect mixing of the agent, and an agent weight of the largest extinguisher in that aircraft compartment. As a result, Halon 1211 safe-use concentrations are lower than in the previous AC. The guidance allows for adjustments for ventilation, localization and agent stratification, resulting in higher safe-use concentrations. You may elect to use safe-use W/V guidance or the minimum safe volume guidance. Both are outlined below. If used, this generally conservative guidance should protect passengers and crewmembers from neat agent toxicity, i.e. both cardiotoxicity and anesthetic effects. a. Agent Safe-Use W/V Guidance. Consider the following: (1) The total agent charge weight of the largest required extinguishers in a compartment divided by the compartment volume should not exceed the safe-use W/V. A4-1 ### Page 42 (OCR) Appendix 4 (2) Multiplication factors, MF Ventilated may be applied to the safe-use W/Vs found in Figure 5 below resulting in higher safe-use agent concentrations in ventilated compartments where the air change time is known. See Figure 6 below or reference report appendix 3, paragraph 7m of this AC for the multiplication factors. These multiplication factors, referred to as the ventilation benefit in the reference report, are based on perfect mixing. Figure 5. Safe-Use Agent W/V for Halocarbon Extinguishers in Unventilated Passenger and Crew Compartments Maximum Safe W/V (Ibs/ft') Sea Level Pressurized Unpressurized Aircraft Agent (For info Aircraft only) (8k ft. CPA) 12.5k ft. 14k ft. 18k ft. 25k HCFC Blend B " 0.00499 0.00371 0.00311 0.00293 0.00249 0.00185 HFC-227ea " 0.0551 0.0409 0.0344 0.0324 0.0275 0.0205 HFC-236fa " 0.0595 0.0442 0.0371 0.0349 0.0297 0.0221 Halon 1211 b 0.00224 0.00166 0.00139 0.00131 0.00112 0.000829 Halon 1211 C 0.00449 0.00334 0.00281 0.00264 0.00225 0.00166 Halon 1301" 0.0260 0.0193 0.0162 0.0153 0.0130 0.00968 a Values are based on safe human concentrations. See reference report appendix 3, paragraph 7m of this AC. b This value is based on the NOAEL Halon 1211 concentration of 0.5%. c This value is based on the LOAEL Halon 1211 concentration of 1.0%. d Safe human concentrations are not available for Halon 1211. The Halon 1211 LOAEL concentration of 1.0% (v/v) has been shown to be safe for humans. See reference report in note a above. However, the safety factor is smaller than that set for the other agents. Figure 6. Multiplication Factors (MF Ventilated) for Ventilated Compartments Air Change Time, + (minutes) HFC-236fa 1 17 12 18 13 121 12 18 1 Halon 1211' Halon 1301 a No MF Ventiluted is applied if air change time is greater than 6. b More conservative MF Ventilated than actual. Based on Halon 1301 MF Ventilated- (3) Safe-use selector curves may be used in lieu of Figure 5 and 6 above. They can be found in the reference report mentioned in paragraph 2a(2) above and can be used to obtain safe-use W/V for ventilated aircraft. A4-2 ### Page 43 (OCR) Appendix 4 (4) Actual concentrations encountered by occupants may be significantly lower than the perfect mixing model concentrations, depending on agent stratification, air distribution, and geometry of a particular aircraft/aircraft compartment and the height and position of the occupant. A correction ultimately may be made for stratification/localization which may further increase the calculated safe-use concentration. See chapter 4, paragraph 4b(3) of this AC. The FAA will publish a report with limited examples of stratification and a methodology for use in determining this correction to adjust the safe-use concentrations for those examples. This report will include a comparison of actual post-discharge halocarbon concentration histories with perfect mixing concentration histories. The safe-use concentrations can be determined from the kinetic solution of equation 6 of the report referenced in appendix 3, paragraph 7m of this AC along with the target arterial concentrations and/or other calculation guidance provided in that report. b. Minimum Safe Volume. This guidance may be used in place of the safe-use W/V guidance. It establishes a baseline minimum volume at which an extinguisher may safely be used, assuming perfect mixing. The minimum safe volume is a useful tool for comparing the toxicity of hand extinguishers with the same fire fighting performance, i.e. the same U.S. - UL rating. The lower the minimum safe volume used, the comparatively less toxic the agent. Therefore, the safest extinguisher of a given rating has the lowest minimum safe volume. Obtain the minimum safe volume of an extinguisher by dividing the charge weight of the agent in the largest extinguisher in an aircraft compartment by the safe-use agent W/V for the appropriate altitude and ventilation. Charge Weight Agent MinimumSafeVolume = Where, F is the safe-use W/V obtained from Figure 5 and 6 of this AC. (2) Extinguishers in Unventilated Compartments. The minimum safe volume for unventilated aircraft should be used when the air change time is unknown or exceeds 6 minutes, and when multiplication factors for ventilated aircraft, MF ventilated, are not available for a particular agent. If the safe-use W/V can not be met for any of the agents, consider the relative neat agent toxicities of extinguishers in Figure 1 when selecting an extinguisher. See Figure 7 for the minimum safe volumes for extinguishers in unventilated compartments. A4-3 ### Page 44 (OCR) Appendix 4 Figure 7. Minimum Safe Compartment Volume for One Extinguisher in Unventilated Compartments. Minimum Safe Volume for One 5 B:C Extinguisher (ft?) Agent Weight® Agent (Ibs) Level only) (info Sea Pressurized 8,000 ft Aircraft CPA 12,500 ft 14,000 ft Non-Pressurized Aircraft 18,000 ft 25,000 ft HCFC Blend B 5.5 1102 1482 1768 1877 2209 2973 HFC-227ea® 5.75 104 141 167 177 209 280 HFC-236fa® 4.75 79.8 107 128 136 159 214 Halon 1211° 2.5 1116 1502 1790 1908 2232 3016 Halon 1211de 2.5 558 751 895 954 1116 1508 Halon 1301° 5.0 192 258 308 327 385 517 a Agent weight for a 5B: C extinguisher is extinguisher dependent. Nozzle design, pressurization differences and other factors can result in different agent weights for extinguishers using the same agent. The tabulated minimum safe volumes should be corrected for the actual agent weight if different from the agent weight in this figure. b Values based on the safe human concentration. See reference report appendix 3. paragraph 7m of this AC. Values are based on the Halon 1211 NOAEL concentration of 0.5% (w.v) Values are based on the Halon 1211 LOAEL concentration of 1.0% (v/v). e Safe human concentrations are not available for Halon 1211. The Halon 1211 LOAEL concentration of 1.0% (v/v) has been shown to be safe for humans. See report mentioned in note b above. Also, the safety factor is smaller than that set for other agents. (3) Extinguishers in Ventilated Compartments. The minimum safe volumes of various single SB:C extinguishers when used in ventilated compartments, and assuming perfect mixing can be obtained by applying applicable multiplication factors found in Figure 6 above as a divisor to the minimum safe volume obtained in Figure 7 above. 3. Extinguisher Weights. Figure 8 below illustrates the fire fighting performance, agent and gross extinguisher weights of some halocarbon and water extinguishers. A4-4 ### Page 45 (OCR) Appendix 4 Figure 8. Fire Extinguisher Performance and Gross Weights UL Class A Class A Class B Class B Agent and Extinguishers Weights® Listing Panel Crib Fire Novice Experienced Halon Halon HCFC HFC- HFC- Fire 1211 1301 Blend B 227ea 236fa Water Agent Agent Agent 2-B:C 1.3 lb N/A 2.5 lb Agent 2.5 lb N/A N/A N/A 2 f 5 A? Gross Wt. Gross Wt. 2.75.1b Gross Wt. 2.3 lb 5.3 lb 5.0 lb Agent Agent Agent Agent 2.5 lb Agent 5.5 lb 5.75 lb 4.75 lb 5-B:C N/A N/A 5 ft 12.5 f Gross Wt. 2.5 lb 3.7 1b* Gross Wt. 9.3 1b Gross Wt. Gross Wt. 9.12 lb 9.5 lb N/A (72) Agent 1-A: 8 ft x 12 layers 5 f? 12.5 fl 3.5 lb N/A N/A N/A N/A N/A 5-B:C 8 ft 6-2x2x20 Gross Wt. in. 4.4 lb (72) Agent Agent Agent 1-A: 8 ft x 12 layers 9 lb 11 b 9.5 lb. 10-B:C 8 ft 6-2x2x20 10 f2 25 f2 Gross Wt. N/A Gross Wt. N/A Gross Wt. N/A in. 15.7 lb 22 lb 21.81 1b (112) Agent 10 ft x 16 layers 22 lb 10 ft 7-2x2x25 NA N/A N/A N/A N/A N/A (2.5gal) 2A in. Gross Wt. 28 lb (112) Agent Agent 2-A: 10 ft x 16 layers 10 f? 25 ti N/A N/A 15.5 lb N/A 13.3 lb. N/A 10-B:C 10 ft 7-2x2x25 Gross Wt. Gross Wt. in. 27 1b 25.6 lb (112) Agent 2A-40 10 ft x 16 layers 40 fi 100 fl 13 lb N/A N/A N/A N/A N/A B:C 10 ft 7-2x2x25 Gross Wt. in. 20 16 Weights are extinguisher dependent. Extinguishing effectiveness is determined by test. Optimization of hardware may result in future listed units with lower gross weights and/or smaller dimensions. b Halon 1211 is no longer in production. However, Halon 1211 extinguishers are still in production using recycled agent. Aircraft Volumes and Ventilation. Figure 9 below provides general information on various size aircraft, i.e. number of seats, volumes and ventilation. Only use this table as general guidance. The accuracy of this data has not been verified. Check aircraft manual for accurate guidance for your aircraft. The information in this table is taken in part from: Hocking. M.B. (1998). Indoor Air Quality: Recommendations Relevant to Aircraft Passenger Cabins. American Industrial Hygiene Association Journal. 59:446-454. A4-5 ### Page 46 (OCR) Appendix 4 Figure 9. Aircraft Volumes and Ventilation Air Change Transport Category Aircraft Per Hour Air Cabin Minimum Change, Number Volume, Reported Minutes of Seats ft' (m') Airbus A300-600 36.7 1.6 266 10135(287) Airbus A310 36.7 1.6 220 8617(244) Airbus A318 35.3 1.7 107 3637(103) Airbus A319 36.2 1.7 124 4238(120) Airbus A320 36.7 1.6 150 4909(139) Airbus A321 40.3 1.5 185 5474(155) Airbus A330-200 31.3 1.9 253 12184(345) Airbus A340-200 31.3 1.9 261 12184(345) Airbus A340-600 35.0 1.7 380 15892(450) Airbus A380-800 34.0 1.8 525 38917(1102) Boeing 727-100 22.9 2.62 5333(151) Boeing 727-200 18.8 3.19 5827(165) Boeing 737-100 26.1 2.30 4238(120) Boeing 737-200 17.7 3.39 4626(131) Boeing 737-300 (42) 14.2 4.23 5262(149) Boeing 747 (26) 14.7 4.08 27899(790) Boeing 757 (48) 15.6 3.85 9747(276) Boeing 767-200 (52) 10.3 5.83 11265(319) Boeing 767-300 (-) 11.1 5.41 15115(428) Lockheed L1011-1/100 17.8 3.37 18964(537) Lockheed L1011-50 19.3 3.11 17445(494) McDonald Douglas DC9-30 27.3 2.20 4379(124) McDonald Douglas DC9-50 18.8 3.19 5227(148) McDonald Douglas DC9-80/MD80 (22) 19.7 3.05 6109(173) McDonald Douglas DC10-10 22.8 2.63 Donald Douglas DC10-40 (35) 14.9 4.03 14797(419) Smaller Commercial Aircraft Bombardier CRJ200 50 2015(57.1) Bombardier CRJ700 19.5 3.1 73 2682(76.0) Bombardier CRJ900 17.3 3.5 94 3228(91.0) Bombardier DASH-S, Q100 & Q200 37 1328(37.6) Bombardier DASH-8, Q400 70-80 2740(77.7) Embraer Brasilia EMB-120 3.8 15.9 30 968(27.4) Embraer ERJ-135 11.1 5.4 37 1650(46.7) Embraer ERJ-145 5.7 10.5 50 1872(53.1) Embraer ERJ-170 11.6 5.2 86 2315(65.6) Embraer ERJ-190 10.7 5.6 124 3203(90.7) A4-6 ### Page 47 (OCR) 01/14/11/ AC 20-42D Appendix 4 Air Change Per Hour Air Cabin Minimum Change, Number Volume, Reported Minutes of Seats it' (m') Fairchild Dornier 328 32 1183(33.5) Saab 340A & 340B 33 1180(33.5) Saab 2000 50 1860(52.7) Rotorcraft Sikorsky S76 7-14 204(5.8) Sikorsky S92 12-24 700(19.8) Bell 206B3 5-7 40(1.1) Bell 407 7 85(2.4) Bell 412 8-15 220(6.2) Bell 430 224(6.4) Small Aircraft Bombardier Challenger 300 19.2 3.1 14 850(24.0) Bombardier Challenger 605 19.0 3.3 14 1150(33.0) Cessna Caravan II 6-8 152(4.3) Cessna Caravan 675 6-8 254(7.2) Cessna Caravan Amphibian 6-8 254(7.2) Cessna Grand Caravan 6-12 340(9.6) Cessna Citation CJ1 2.8 31.3 4-7 300(8.5) Cessna Citation CJ2 3.3 18.3 6-9 350(9.9) Cessna Citation X 1.7 35.1 10 593(17) Cessna Corsair, Conquest I 6-8 193(5.5) Cessna 152 2 77(2.2) Cessna 210C 6 140(3.9) Cessna 414 6-8 226(6.4) Cessna 421B 1.8 33,2 6-8 217(6.2) Dassault Falcon 7X 10.8 5.5 12 1836(52.0) Dassault Falcon 50EX 8.9 6.7 1059(30.0) Dassault Falcon 900EX 9.1 6.6 10 1695(48.0) Small Aireraft Dassault Falcon 2000EX 10.5 5.7 8 1483(42) Embrear Legacy 600 24.0 2.5 13 1650(47.0) Embrear Phenom 100 28.7 2.09 4 300(8.5) Embrear Phenom 300 29.0 2.1 7 357(10.1) Gulfstream Turbo Commander 6 184(5.2) Gulfstream Jetprop 184(5.2) Gulfstream G100 367(10.4) A4-7 ### Page 48 (OCR) Appendix 4 Air Change Per Hour Air Cabin Minimum Change, Number Volume, Reported Minutes of Seats ít' (m') Gulfstream G150 6-8 465(13.2) Gulfstream G200 6-8 868(24.6) Gulfstream G350/450 12-16 1,525(43.2) Gulfstream G550 14-18 1669(47.3) Gulfstream G650 11-18 2138(60.5) LearJet 31A 35.0 1.7 10 271(7.7) LearJet 40 36.0 1.7 6-9 363(10.3) LearJet 45/45XR 6-8 410(11.6) LearJet 60/60XR 26.0 2.3 6-8 453(12.8) Pilatus PC12 330(9.4) Piper PA31T Cheyenne 151(4.3) Raytheon Beechcraft King Air B200 32.0 1.9 7-9 393(11.1)" Raytheon Beechcraft King Air B300/350 28.0 2.1 9-11 443(12.5)" Raytheon Beechjet 400/Hawker 400XP 8 305(8.6)" Raytheon Premier 1 27.0 2.2 6-8 400(11.3)" Rockwell Gulfstream Commander GC-1000 249(7.1) Socata TBM-700 estimated by Pilatus 155(4.4) Sino Swearingen SJ30-2 190(5.4) VisionAire Vantage 310(8.8) a Includes lavatory and internal baggage compartment. 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