+-----------------------------------+----------------------------------+
| ![](media/image1.w                | **Advisory**                     |
| mf){width="0.38472222222222224in" |                                  |
| height="0.3645833333333333in"}    | **Circular**                     |
|                                   |                                  |
| U.S. Department                   |                                  |
|                                   |                                  |
| of Transportation                 |                                  |
|                                   |                                  |
| **Federal Aviation**              |                                  |
|                                   |                                  |
| **Administration**                |                                  |
|                                   |                                  |
| ###                               |                                  |
| {#section .Paragraph .unnumbered} |                                  |
+-----------------------------------+----------------------------------+

###  {#section-1 .Paragraph .unnumbered}

+-----------------------------------+----------------+----------------+
| **Subject:** AIRCRAFT FIRE        | **Date:**      | **AC No:**     |
| EXTINGUISHING AGENTS              | 7/08/04        | 150/5210-6D    |
|                                   |                |                |
|                                   | **Initiated    | **Change:**    |
|                                   | by:** AAS-100  |                |
+-----------------------------------+----------------+----------------+

**1. PURPOSE.** This Advisory Circular (AC) provides guidance for
reference material covering Aircraft Fire Extinguishing Agents.

**2. CANCELLATION.** Advisory Circular 150/5210-6C, dated January 28,
1985, is cancelled.

**3. APPLICATION.** The Federal Aviation Administration (FAA) recommends
the guidelines contained in this AC for Aircraft Fire Extinguishing
Agents. This AC is not mandatory and does not constitute a regulation.
However, the information it contains provides an acceptable methodology
for complying with Title 14 of the Code of Federal Regulations (CFR),
part 139, *Certification of Airports (Part 139)*. In the event of a
conflict, part 139 takes precedence over the other documents identified
in this AC.

**4. APPLICABLE DOCUMENTS.**

The following documents are applicable to the extent specified in this
AC:

**4.1 Code of Federal Regulations (CFR).**

> 14 CFR part 139, *Certification of Airports (part 139)*.

**4.2 National Fire Protection Association (NFPA).**

NFPA 18, *Standard on Wetting Agents*, 1995 edition.

> NFPA 403, *Standard* *for Aircraft Rescue and Fire-Fighting Services
> at Airports,* August 7, 2003, edition.
>
> NFPA 412, *Standard for Evaluating Aircraft Rescue and Fire-Fighting
> Foam Fire Equipment,* 2003 edition.

**4.3 Military Specifications.**

> MIL-F-24385F, *Fire Extinguishing Agent, Aqueous Film Forming Foam
> (AFFF) Liquid Concentrate, for Fresh and Seawater,* dated January 7,
> 1992.

**4.4 Underwriters Laboratory (UL) Standards.**

> UL 162, *Standard for Safety for Foam Equipment and Liquid
> Concentrate,* dated March 30, 1994.

**5. HOW TO ORDER.**

a.  Copies of part 139 may be purchased from:

> Superintendent of Documents
>
> U.S. Government Printing Office
>
> Washington, DC 20402
>
> b\. Copies of National Fire Protection Association (NFPA) Standard No.
> 403, *Standard for Aircraft Rescue and Fire-fighting Services at
> Airports*, and Standard No. 412, *Standard for Evaluating Aircraft
> Rescue and Fire-Fighting Foam Fire Equipment,* may be ordered from:
>
> National Fire Protection Association
>
> 1 Batterymarch Park
>
> Quincy, MA 02269
>
> c\. Copies of UL 162, *Standard for Safety for Foam Equipment and
> Liquid Concentrates,* can be purchased from:

Underwriters Laboratory, Inc.

Customer Service

1285 Walt Whitman Road

Melville, NY 11747-3081

d\. A printed copy of this and other ACs can be ordered from:

> U.S. Department of Transportation
>
> Annmore East Business Center
>
> 3341 Q 75^th^ Avenue
>
> Landover, MD 20785
>
> e\. Electronic copies of FAA ACs and part 139 may be obtained from:
>
> Internet: http://www.faa.gov/arp

![](media/image2.png){width="2.0833333333333335in"
height="0.4479166666666667in"}

David Bennett

Director, Office of Airport Safety and Standards

[**TABLE OF** **CONTENTS**]{.underline}

[CHAPTER 1. BACKGROUND. 1](#chapter-1.-background.)

[1.1 GENERAL. 1](#general.)

[1.2 DEFINITIONS. 1](#definitions.)

[1.2.1 Primary Agents. 1](#primary-agents.)

[1.2.2 Supplementary Agents. 2](#supplementary-agents.)

[1.2.3 Other Agents. 2](#other-agents.)

[1.2.4 Theoretical Critical Fire Area (TCA).
3](#theoretical-critical-fire-area-tca.)

[1.2.5 Practical Critical Fire Area (PCA).
3](#practical-critical-fire-area-pca.)

[1.2.6 Control Time. 3](#control-time.)

[1.2.7 Extinguishment Time. 3](#extinguishment-time.)

[CHAPTER 2. QUANTITIES FOR AIRPORTS SERVING DOT-CERTIFICATED AIR
CARRIERS/COMMERCIAL SERVICE.
3](#chapter-2.-quantities-for-airports-serving-dot-certificated-air-carrierscommercial-service.)

[CHAPTER 3. QUANTITIES FOR GENERAL AVIATION AIRPORTS.
4](#chapter-3.-quantities-for-general-aviation-airports.)

[CHAPTER 4. COMPATIBILITY OF AGENTS.
4](#chapter-4.-compatibility-of-agents.)

[CHAPTER 5. EXTINGUISHING AGENT SUBSTITUTES.
4](#chapter-5.-extinguishing-agent-substitutes.)

[CHAPTER 6. PERFORMANCE REQUIREMENTS.
4](#chapter-6.-performance-requirements.)

[CHAPTER 7. TESTING AND QUALITY ASSURANCE.
4](#chapter-7.-testing-and-quality-assurance.)

[7.1 QUALITY CONTROL. 4](#quality-control.)

[7.2 RESPONSIBILITY FOR INSPECTION. 4](#responsibility-for-inspection.)

[CHAPTER 8. ENVIRONMENTAL 5](#chapter-8.-environmental)

[8.1 ENVIRONMENTAL ISSUES 5](#environmental-issues)

[APPENDIX A. Related FAA Advisory Circulars.
7](#appendix-a.-related-faa-advisory-circulars.)

**Intentionally left blank.**

# CHAPTER 1. BACKGROUND.

## 1.1 GENERAL.

This AC provides reference information on the following agents:

-   Primary aircraft fire extinguishing agents

-   Supplementary aircraft fire extinguishing agents

-   Other aircraft fire extinguishing agents

## 1.2 DEFINITIONS.

The following definitions do not include numerical quantities. These can
be found in NFPA 403, Table 5.3.1 (b), as well as additional agent
quantities to be carried.

### 1.2.1 Primary Agents. {#primary-agents. .unnumbered}

Foam used for extinguishing aircraft fires should consist of an
aggregation of bubbles of a lower specific gravity than that of
hydrocarbon fuels or water. The foam should have strong cohesive
qualities and be capable of covering and clinging to vertical and
horizontal surfaces. Aqueous foam cools hot surfaces by its high water
retention ability and must flow freely over a burning liquid surface to
form a tough, air-excluding blanket that seals off volatile flammable
vapors from access to air or oxygen. Good-quality foam should be dense
and long lasting, capable of resisting disruption by wind or draft,
stable to intense thermal radiation, and capable of re-sealing in event
of mechanical rupture of an established blanket.

**1.2.1.1 Aqueous Film Forming Foam (AFFF).**

These liquid concentrates consist of perfluorinated surfactants(s) with
a foam stabilizer and viscosity control agents. The AFFF acts both as a
barrier to exclude air or oxygen and, in addition, produces an aqueous
film on the fuel surface capable of suppressing the evolution of fuel
vapors. Ideally, the foam blanket produced by the AFFF should be of
sufficient thickness so as to be visible before fire fighters rely on
its effectiveness as a vapor suppressant.

**1.2.1.2 Fluoroprotein Foam (FP).**

Fluoroprotein Foam is simulated foam that is manufactured from protein
foam concentrates to which fluorochemical surfactants have been added.
This increases the fluidity of the foam and offers a good burn back
resistance. The manufacturer of the foam-making equipment should be
consulted as to the correct concentrate to be used in any particular
system (the proportioners installed must be properly designed and/or set
for the concentrate being used).

**1.2.1.3 Film Forming Fluoroprotein (FFFP) Foam.**

These agents are also based on protein foam formulations. They are
produced by increasing the quantity and quality of the fluorocarbon
surfactants added to the protein hydrolyzate. By doing this, the surface
tension of the resulting solution that drains from the expanded foam is
reduced to the point that it can spread across the surface of a liquid
hydrocarbon fuel.

**1.2.1.4 Protein Foam.**

These liquid concentrates consist primarily of hydrolysis products of
various proteinaceous materials. They also contain stabilizing additives
and inhibitors to protect against freezing, to prevent corrosion of
equipment and containers, to resist bacterial decomposition, to control
viscosity, and to assure readiness for use in emergencies. Foam liquids
of different types or different manufacturers should not be mixed unless
it is determined that they are compatible and/or completely
interchangeable.

### 1.2.2 Supplementary Agents. {#supplementary-agents. .unnumbered}

Supplementary agents are also referred to as secondary agents. Agents
that fit into this category are carried on rescue vehicles to handle
unique fire fighting requirements most common to airport fire fighting
use. Supplementary agents are employed either singly or in combination
with foam to accomplish particular aircraft fire fighting operations
such as a three dimensional running fuel fires (reference NFPA 403,
Annex A, § A.5.2 (1)).

This class of agents include:

-   Dry Chemical

-   Halotron® I

-   Carbon Dioxide

**1.2.2.1 Dry Chemical.**

The earliest use of dry chemical in aircraft fire fighting included the
use of sodium bicarbonate-based products. Today, the U.S. airport fire
fighting industry relies almost exclusively on the use of
potassium-based chemicals as auxiliary extinguishing agents due to their
compatibility with AFFF agents and their reliable fire performance.

**1.2.2.2 Halotron® I.**

Subsequent to the U.S. decision to halt production of halon as part of
the Montreal Protocol (reference NFPA 403, Appendix A, §A.5.2 (2)) and
the use of halon-based agents (e.g., Halon 1211) in live fire training
because of its environmental effects, the FAA teamed with other agencies
and industry and identified an acceptable alternative to using
halon-based agents in airport rescue firefighting vehicles. Several
potential agents were evaluated. Only the Halotron® I product has
completed the full-scale fire test performance evaluation and was
approved as an alternative fire fighting agent to Halon 1211 for airport
fire fighting use. Halotron ® I has additionally been deemed to be an
environmentally acceptable replacement for Halon 1211 by the
Environmental Protection Agency. Due to the slight differences in
specific gravity of these two chemicals in a 1:1 by-volume basis,
approximately 468 pounds of Halotron® I can be placed in the existing
vessel (tank) that holds approximately 500 pounds of Halon 1211. Fire
performance tests have shown that Halotron® I will generally suppress or
extinguish fires in the same manner as Halon 1211. In considering the
substitution of Halotron® I for Halon 1211, the ratio for equivalency in
performance might be as great as 1.5 to 1 pound by weight.

**1.2.2.3 Carbon Dioxide.**

Tests show that low-pressure carbon dioxide (CO~2~) is more effective in
aircraft rescue and fire fighting operations than high pressure CO~2~.
The tests further indicate that CO~2~ can be given parity with dry
chemical powder on the basis of 4.4 pounds of CO~2~ gas per 2.2 pounds
of dry chemical.

### 1.2.3 Other Agents. {#other-agents. .unnumbered}

In general there are other special-use fire extinguishing agents
available to airport firefighting services. In particular, those agents
used to combat Class D fires, such as magnesium fires, are referred to
as combustible metal agents. These agents can be either in the form of
liquid or powder. For information on powder agents, refer to NFPA 403
Annex A, §A.5.5.

Under certain fire situations "wetting agents" may be appropriate. A
wetting agent is defined as a chemical compound that, when added to
water in proper quantities, materially reduces its surface tension,
increases its penetrating and spreading abilities, and might also
provide emulsification and foaming characteristics. These agents should
be discharged through an in-line proportioning system to a handline so
as not to contaminate the vehicles primary foam distribution system.
These agents should not be mixed in any primary agent tanks. For further
information on wetting agents, refer to NFPA 18, *Standard on Wetting
Agents*.

### 1.2.4 Theoretical Critical Fire Area (TCA). {#theoretical-critical-fire-area-tca. .unnumbered}

The TCA serves as a means of categorizing aircraft in terms of the
magnitude of the potential fire hazard in which they may become
involved. It is not intended to represent the average, maximum, or
minimum spill fire size associated with a particular aircraft. For
information on TCA, refer to NFPA 403, Annex B, §B.1.1.

### 1.2.5 Practical Critical Fire Area (PCA). {#practical-critical-fire-area-pca. .unnumbered}

The PCA and the related quantities of extinguishing agents are based on
criteria formulated during the Second Meeting of the International Civil
Aviation Organization (ICAO) Rescue and Fire Fighting Panel (RFFP II) in
June 1972. RFFP II developed material indicating the practical area is
two-thirds of the theoretical area based on the Panel's work, which
included a study of extinguishing agents used on actual aircraft fires.
In 99 out of 106 studied fires, the quantities of agents used were less
than those previously recommended by ICAO. For information on PCA, refer
to NFPA 403, Annex B, §B.1.1.

### 1.2.6 Control Time. {#control-time. .unnumbered}

The control time is the time required from the arrival of the first fire
fighting vehicle and the beginning of agent discharge to reduce the
initial intensity of the fire by 90 percent. The equipment and
techniques to be used should be capable of controlling the fire in the
PCA in 1 minute. For information on control time, refer to NFPA 403,
Annex B, §B.2.

### 1.2.7 Extinguishment Time. {#extinguishment-time. .unnumbered}

Extinguishment time is the time required from the application of the
agent of the first fire fighting vehicle to the time the fire is
extinguished. For information on extinguishment time, refer to NFPA 403,
Annex B, §B.2.

# CHAPTER 2. QUANTITIES FOR AIRPORTS SERVING DOT-CERTIFICATED AIR CARRIERS/COMMERCIAL SERVICE.

part 139, §139.315 is to be used to determine the aircraft rescue and
firefighting Index (A through E) for airports serving Department of
Transportation (DOT) certificated air carriers/commercial service. These
numbers can then be converted to NFPA categories using NFPA 403, Chapter
4, Table 4.3.1. The extinguishing agents, quantities, and discharge and
response capability for each Index is referenced in NFPA 403, Chapter 5,
Table 5.3.1 (b), in U.S. customary units and could be used to comply
with §139.315. NFPA 403, Annex B, additionally describes the methodology
used to arrive at the designated control times (§B.2), discharge rates
(§B.3), and quantities of agents to be provided (§B.4 and §B.5). It
should be noted that part 139 takes precedence and that NFPA 403 may, in
some cases, exceed part 139 requirements.

Each truck, when purchased, should be equipped with its design capacity
of extinguishing agents. For operating and training purposes, airports
should also provide: (1) Twice the quantity of agents carried on each
truck available in the fire station and (2) A supply of agents to be
used for training. Note also that §139.317(i) requires each vehicle that
is required to carry AFFF to carry AFFF in an appropriate amount to mix
with twice the water required to be carried by the vehicle.

# CHAPTER 3. QUANTITIES FOR GENERAL AVIATION AIRPORTS.

The Indexes for general aviation airports are identified in NFPA 403,
Chapter 4, Table 4.3.1 and cover the areas not governed by the FAA. The
extinguishing agents, quantities, and discharge and response capability
for each Index are referenced in NFPA 403, Chapter 5, Table 5.3.1 (b),
in U.S. customary units. NFPA 403, Annex B, additionally describes the
methodology used to arrive at the designated control times (§B.2),
discharge rates (§B.3), and quantities of agents to be provided (§B.4
and §B.5).

# CHAPTER 4. COMPATIBILITY OF AGENTS.

The compatibility of agents is discussed in NFPA 403, Chapter 5, §5.4.

# CHAPTER 5. EXTINGUISHING AGENT SUBSTITUTES.

Extinguishing agent substitutes are discussed in part 139, §139.317 (i).

# CHAPTER 6. PERFORMANCE REQUIREMENTS.

AFFF agents must meet the requirements of Mil-F-24385F. It is important
to note that if one vendor's foam is mixed with another vendor's foam in
the re-servicing process, there must be compatibility between foams to
prevent gelling of the concentrate.

When used, FFFP, FP, and protein foam must meet the applicable
performance requirements discussed in UL 162 (Type 3 application),
*Standard for Safety for Foam Equipment and Liquid Concentrates*.

# CHAPTER 7. TESTING AND QUALITY ASSURANCE.

## 7.1 QUALITY CONTROL.

While it is recognized that acceptance testing of extinguishing agents
is necessary, the technical characteristics, quality, stability
compatibility, etc. cannot be determined during other system tests or
demonstrations (e.g., for trucks). Therefore, airport management should
request that prospective bidders or suppliers of fire extinguishing
agents furnish proof of tests on performance and quality by a recognized
testing laboratory. Technical data on the evaluation of agents and
information on the characteristics of foam extinguishing agents are
contained in NFPA 412, Chapter 5.

## 7.2 RESPONSIBILITY FOR INSPECTION.

Unless specified by the airport owner, the manufacturer is responsible
for the performance of all inspection requirements as stated in §7.1
above. Unless specified in the contract, the manufacturer may use
his/her own or any other facilities suitable for the performance for the
inspection requirements.

# CHAPTER 8. ENVIRONMENTAL

## 8.1 ENVIRONMENTAL ISSUES

For Federal environmental and health concerns, and issues in the use of
aircraft fire fighting agents, contact the following organizations
concerning information:

Environmental Protection Agency (EPA)

Ariel Rios Building

1200 Pennsylvania Ave., N.W.

Washington, DC 20460

\(202\) 272-0167

[www.epa.gov](http://www.epa.gov/)

Occupational Safety and Health Administration (OSHA)

200 Constitution Ave., N.W.

Washington, DC 20210

1-800-321-OSHA

[www.osha.gov](http://www.osha.gov/)

For information on material safety, contact:

Material Safety Data Sheets

121 Shivel Drive

Hendersonville, TN 37075

(877)673-7123

[www.msdssearch.com](http://www.msdssearch.com/)

For information on state and local agencies pertaining to specific
airports, refer to the appropriate organization in your state and/or
local area.

**Intentionally left blank.**

# APPENDIX A. Related FAA Advisory Circulars.

AC 150/5210-7, *Aircraft Rescue and Firefighting Communications*

AC 150/5210-14, *Airport Fire and Rescue Personnel Protective Clothing*

AC 150/5210-17, *Programs for Training of Aircraft Rescue and
Firefighting Personnel*

AC 150/5220-10, *Guide Specification for Water/Foam Aircraft Rescue and
Firefighting Vehicles*

AC 150/5220-19, *Guide Specification for Small Agent Aircraft Rescue and
Fire Fighting Vehicles*

AC 150/5300-13, *Airport Design*, Appendices 12 and 13