Adv isory Circular U.S. Department of Transportation 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 circular (AC) gives you guidance for the fire-fighting effe tivenes selection and safe-use ofhand 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.
~~ ~ DavidW. Hempe Manager Aircraft Engineering Division ircraft Certification Service
01/14/11 AC20-42D Table of Contents Pa,·agraph Page
Chapter 1. General Information about this Advisory Circular (AC)1
1. What is the Purpose of this Advisory Circular (AC)?1
2. Wbo is this AC for?2
3. What has Changed in this AC from the Previous AC?2
4. Does this AC cancel any prior A Cs?3
5. Where Can 1find This AC and other FAA publications?3
Chapter 2. Gaining FAA App roval for Fire Extinguishers4
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 Extinguisher9
I. What are the Different Types of Pires?................................................. ,9
2. What do the Noo1eral Ratings Mean?9
3. What Extinguishing Agents are Appropriate for the Different Types of Pires?9
4. What Extinguishing Agents are Compatible witll Aircraft Materials?11
5. What are the Operating Temperature Tolerances?11
6. General Guidelines for Hand Fire Extinguishers?12
Chapter 4. Safe Use of Hand Fire Extinguishers ..... _14
I. What Basic Fire Fighting Training Should be Proyjded?14
2. What are Some General Guideline s for the Safe-Use
of Halocarbon Extinguishers?15
3. How to Prevent Hypoxia in an Unpressurized Aircraft16
4. What are the Guidelines on the Selection of Halocarbon Extinguishers?17
5. How to Safely Use Halocarbon Extinguishers in Accessible Cargo Compartment s19
6. How to Inspect and Main tain the Hand Fire Extinguisher for
Continued Safe-Use20
ii
Paragraph Page
Chapter 5. Locating and Mounting Hand Fire Exti ngu ishers22
1. Where to Locate and MoW1t Hand Fire Extinguishers in
Passenger Compartments22
2. How to Locate and Mount Hand Fire Extinguishers in Flight
Deck Compartment s23
3. How to Locate and Mow1t Hand Fire Extinguishers in Small Single Engine and
Multiengine Aircraft ...... . .................. .. .......... .......... ,23
4. How Many !-:land Extinguishers Should I Install23
Appendix 1. List of Acronyms ......................................................................................... Al -1 Appendix 2. Definitions and Terms ................................................................................ A2- 1
Appendi x 3. Related Publicati ons and How to Get ThemA3-1
I. Code of Federal Regul ations (CFR)A3-1
2. FAA Airworthiness Dire ctive (AD)A3-1
3. PAA Advisory Circulars (AC) .............................. ............................................... ......... A3- l
4. FAA Technical Standard Order (TS O)A3-2
5. f AA Safety Alerts for Operators (SAFOS) and lnformation for Operator s (lnFOs) ... A3-2
6. FAA Training VideosA3-2
7. Reports and Paper sA3-2
8. American Society of Testing and Materials (ASTM) StandardsA3-4
9. Factory Mutual Research Corp. (FM)A3-5
I 0. Internat ional Organization for Standardization (ISO)A3-5
l l. Natio nal Fire Protectio n Association (NF PA) ...................... ............. ..................... ...... A3 -5
12. RTCA lnc. Documents ..... ................ ......................................................................... ... AJ -6
13. SAE DocumentsAJ-6
14. Underwriter s Laboratorie s, lnc (UL)A3-6
iii
01/14/1 1 AC 20-420 Paragraph Page
Appendix 4. Explanatory MaterialA4-1
I. Effective Throw Ranges ............................................................................................... A4- l
2. Safe-Use GuidanceA4-1
3. Extinguisher WeightsA4-4
4. Aircraft Volumes and VentilationA4-5
Figure I.
Table of Figures
Relative Toxi city of 5 B:C Halocarbon Exti nguishersJ8
Figure 2. Mininmrn Number of Hand Fire Extinguishers Required for Trans port Category
Aircraft Passenger Compartments24
Fig ure 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- l Figure 5. Safe-Use Agent WN for Halocarbon Extinguishers in Unventilated
Passenger and Crew CompartmentsA4-2
Figure 6. Multiplication Factors (MF ventilated) for Ventilated CompartmentsA4-2
Figure 7. Minimum Safe Compart ment Volume for One Exti nguisher in UnventiJated
Compartme ntsA4-4
Figure 8. Fire Extinguisher Performance and Gross WeightsA4-5
Figure 9. Aircraft Volume s and VentilationA4-6
iv
0J/14/11 AC20-42D Chapter 1. General Information about this Advisory Circular {AC} I . What is the Purpose of this Advisory Circ ular (AC)?
a. We provide guidance for fue-figbting effectiveness, selection, location and mounting of hand fire extinguis hers.
b. We establish the halocarbons hydrochlorofluorocarbon (HCFC) Blend B, bydrofl uorocarbon (HFC)-227ea, and HFC-236fa as FAA approved replacement agents to Halon 12 I 1 and Halon 1301.
c. This AC recommends that you transition to using these new halocar bon clean agent s in fire exti nguishers kept onboar d aircraft and rotorcraft. We exp lain how to gain certification for halocarbon clean agent extingujshers intended to replace Halon 1211 hand-held extinguishe rs.
d. This AC recommends that dry chemical, dry powde r, and carbon dioxide hand ex tinguishers, in general. should not be used in aircra ft.
e. We also explain how to gain Federal Aviation Admin istratio n (FAA) certification for replacement agent fire extinguishers, which you m ay use to comply wjth 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 wh.ich includes a hidden fire test and a seat fire/tox icity test.
g. This AC recognize s that toxicity ofhalocarbon agents and their decomposition product s is a conccm and should be a consideration for extinguisher selection. H oweve r, given the variabi I ity of extinguishers, application, compartment sizes and air change times, establishing specific selection criteria i s impractical. The tox icity hazard is a seco ndary concern to an unextingui shed in-flight fire.
h . This AC provides new general guidance in lhe form of safe-use weight -per uni t volume (W/V) that may be usefuJ in extinguisher selectio n, and estab lishes marking criteria for halocarb on extinguishers.
i. We show how to reduce the health and safe ty risk of exposure to halocarbon clean agent s and how to use halocarbo n clean agent fire exti nguishers.
j. We offe r updated guidance on the continued safe-use of Halon 1211, H alon 1301, and Halo n 1211 / 130 1 Halon blend extinguishers.
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 extingui shers kept ooboard aircraft and rotorcraft . However , if you use the means described, you must follow it entirely .
2. Who is this AC for?
a. We wrote this AC for those responsible for selecting, approving, purchasing , and maintaining hand fu-e extinguishers . The guidance in this AC is also for manufacturers, installers, modifier s, owners , and operators of airplanes and rotorcrafr.
b. This AC is a method of compliance for transport category aircraft. Operators of nontransport category airplane s or rotorcraft should become familiar with the information , precautions, and the safe-use guidance in this AC.
c. Existing halo11 handhe1d 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 fostallations on existing approved type design aircraft . These extinguishers remain suitable for continued use based on a history of safe use ofhalon extingufahers 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?
a. Repla cement halocarbon clean agents were devel oped 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 l1alon use in aircraft .
b. Since 1994, Halon 1211 bas 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 Band 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 health.
c. Safe-use guidance is provided for Halon 1211 and Halon 1301 and blends of these agents . Safe-use concentrati ons of Halon 1211 are lower than in the previous AC, because the guidance in this AC is more conservative .
01/14/ 11
4. Docs This AC Cancel Any Prior A Cs? 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: hrtp: rgl.foa.gc.w'. See appendix 3 in this AC for additional information and related documentation.
Chapter 2. Gaining FAA Approval for Fire Extinguishers
1. How are Hand Fire Extinguishers Approved?
a. Federal Regulations for Hand Fire Extinguishers. Hand fire extinguishers are required under 14 CFR §§ 23.851, 25.851(a)(l), 29.851(a)(l), 29.853(e) & (f), 91.513(c),
119.25, 12l.309(c), and 135.155. We approve hand fire extinguishers to be used on aircraft W1der 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-Cl 9.
Note: Although 14 CFR parts 91 and 125 don't require our approval ofhand fire extinguishers. we consider the infonnation in this AC acceptable for use by Part 91 and I 25 operators.
b. Extinguishers Approved Under lndustr y Standards Organization s. 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 addjtion, 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 7 I I, Rating and Fire Testing ofFire 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 CFR § 162.028.
c. 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 lb above. Hand extinguishers produced in the U.S. or those used on airplanes and/or rotorcrafi operated within the U.S. should meet U.S. - UL fire rating standards.
(l) Large Aircraft. The required hand extinguishers should be listed and have a minimum U.S - UL 58: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 ofup to 200 tr3.
2. How are Halon 1211 Replacement Extingui shers Approved? Hand extinguisher replacement agents. such as the halocarbon clean agents intended to replace lhe required 2 ½ pound U.S. - UL 58:C Halon 1211 extinguishers, may be approved for use on aircraft if the ageat complies with the following requirements :
a. Replacement Agent Health and Environment App rova l
(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 environme ntal risk of a proposed replacement agent.
(2) The three halon replacement agents covered by tbfa AC were evaluated under the SNAP program. Halocarbon clean agents HCFC-Blend B, HFC-227ea, and HFC- 236fa are approved for environmenta l and toxicological acceptability.
b. Replacement Agent Band Extingu isher 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 ofreplacement agents should be coordi nated with and approved by yow· loca l ACO with the support offAATC. These fire tests ensure that the replacement agent extinguishers provide equivalent fire fighting performance to Halon I 21 J. Clean agent extingui shers designed to replace the required 2 ½ pound Halon 121 I extinguisher onboard aircraft should compl y with the following MPS provisions;
(I) Hidden Fire Test. The hidden fire test evaluates the ''flooding'' characteristics of the replacement agent against a bidden 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 perfonnance. Each required 5B:C extinguisher model shou ld pass this test to be certified as a Halon l 21 1 replacement on aircraft.
(2) Seat Fire/Tox icity Test. The seat fire test is a baseline test that evaluates the effective ness of the replacement agent in fighting a flammable fluid seat fire scenario and the assoc iated 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 condition s and ensures an acceptable level of toxicity for the thermal decomposition products of the replacement agenl If a particular required 5B:C extinguisher model passes the seat fire/toxicity test, other models of extingui shers do not need to be tested, if the same agent is used Note l : 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.
(3) HCFC-Blend B, HFC-227ea, and HFC 236fa have demonstrated to meet the MPS and are approved for use.
c. Nationa l 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 lb 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 extinguisbers employing halocarbon clean agents replacing Halon 1211, the following American Society of Testing and Materials (ASTM) specifications apply:
(I) 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 Specfficationsfor HFC-227 ea, 1,1,1,2,3,3,3-1-Jeptafl,owopropane (CF1CHFCF1)i
(3) HFC-236fa must meet ASTM D 6541-05 , Standard Specification for HFC-236a , 1.1,1.3.3,3 -Hex~fluoropropane (CF1CH 2CF3)~ or
(4) New Halon 1211 replacement agents must have and meet an applicableASTM or equi valent specification.
(5) Fire extinguisher manufacturers are responsible for the validation of agent purity whether using new or recycled agent.
e. Marking. If you are a manufactu rer, each of your models ofU.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 wjth 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 Contaio i.ng New Replaceme nt Agents.
Nothing in this AC is intended to restrict new technologies or use of new rep lacement agents provided they meet the regulations and guidance prescnbed in paragraph 2 above.
(l) 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(l) is not yet officially published for a particular halocarbon agent, use the NOAEL values approved under the SNAP program mentioned in paragraph 2a(l) 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 lo determine safe-use W/Vs in the absence of published FAA safe-use guidance. Safe-use WNs may be calculated using EPA 's NOA EL values following the methodology outlined in append 1x 3 refere nce paragraph 7 m of this AC.
(3) The FAA Technical Center (FAA TC) intend s to publish future guidance on handh eld exti nguis hers. Tb.is guidanc e will includ e safe-use WN for vent ilated compartments using FAA approved fire extinguishers conta ining halon replacement agents introduced after the issuance of this AC.
3. flow are Balon Extinguishers Approved?
a. National Certification. Required halon hand-held fire extinguishers approved for use on aircraft should have a minimum rating of UL 58:C. Halon 1301 and Halon 1211/1301 blends are also used. Halogenated fire exti nguishers must compl y with U.S. - UL 1093, Halogenated Agent Fire Excinguishers, or equivalen t, for Halon 12 1 l, Halon 130 l and Halon 1211/ 1301 blends per U.S. - UL 711 or equivalent (see paragraph lb above). 1l should be noted that on March 12, 2009, UL announced the withdrawal of US - UL 1093 and the continuance of exist ing certifications to the withdrawn US - UL 1093. UL will no longer accept the submiltal of new or revised products. but a11 current comp liant product s covered under US - UL 1093 will continue to be authorized to bear the clas sification mark of Underwriters Laboratories Inc. until October 1, 20 14.
b. Specifications for Approved Balon Agents. For hand fire extinguis hers that still emp loy halogenated agents, only Halon 1211 , Halon 130 l, or b lends of the two have been previously approved and used aboar d aircraft. The follow ing spec ificatio ns cover the requirements for halogenated agents:
( I) Halon 12J l should meet the requirements of ASTM D76 73-10 , Standard Specificarion for Halon 1211 -Bromochlorodifluoromethane (CF1CIB1~). or ISO 7201-1 :1989, Fire protection -- Fire extinguishing media -- Halogenated Hydrocarbons - Part 1:
Specifications for Halon 1211 and Halon 1301.
(2) Halon 130l should meet the requirements of ASTM D5632-08. Standard Specificarion for Halon I 301-Bromotrijluoromethane (CF3Br}), or ISO 7201-1: 1989.
(3) Hand fire extinguishers with halon agents may continue to be used on aircraft as long as recycled halon ofproven 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 extingwsbers 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.
c. Marking. If you are a manufacturer, mark your halon extinguishers pennanently 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.