Record of Communication between the Federal Aviation Administration (FAA) and the 

European Aviation Safety Agency (EASA) on Revised Class B and New Class F Cargo 

Compartment Rule

Dates of Communications: February 3, 11, 12, 27 and 28, 2014.

September 11 and 26, 2014.

November 24 and 25, 2014.

Participants: Peter Chittenden, EASA Manager Cabin Safety Expert

Patrick Louchez, EASA Cabin Safety Expert

Thomas Ohnimus, EASA Senior Expert for Cabin Safety

Stephen Happenny, FAA Senior Aerospace Engineer/Safety Engineer,

Environmental Control Systems & Fire Protection Systems

Mr. Happenny conducted discussions with the EASA representatives listed above, via e-mail and 

telephone, during the time period provided above. The discussions were conducted to confirm

harmonization of the purpose and effect of the FAA proposed rules and guidance material with 

that of the corresponding EASA regulations (i.e., Certification Specifications for Large 

Aeroplanes (CS-25) 25.851, 25.855, and 25.857) and regulatory guidance (i.e., Acceptable 

Means of Compliance (AMC) 25.851(a)(2), (b), and (c)). The discussions addressed the 

following issues:

1. Accessibility of a Class F cargo compartment:

Mr. Happenny contacted EASA to confirm that the purpose and effect of our rule for Class F 

cargo compartments was the same as EASA’s, since we included additional phrases in our 

rule text that are not in EASA’s corresponding rule. One of the phrases (“located on the main 

deck”) is in EASA’s means of compliance for their corresponding rule and one is not

(“accessible in flight”). The discussions confirmed that the purpose and effect is the same—

to ensure that Class F cargo compartments are only placed on the main deck—and including 

that restriction within our rule accomplished the same effect as EASA’s current interpretation 

of their regulations and their associated AMC, which are of a more mandatory nature than the 

FAA’s advisory circulars. In discussing “accessible in flight,” EASA provided an example of 

a certification project that they approved in which a Class F cargo compartment was not 

accessible in flight. After further discussion, the FAA concluded that requiring accessibility 

in flight was overly restrictive, and unnecessary to restrict Class F cargo compartments to the 

main deck and achieve harmonization.
2. References to industry standards/requirements within advisory circulars (AC) 25.851-X and 

AC 25.857-X, which do not appear in AMC 25.851(a)(2), AMC 25.851(b), and AMC 

25.851(c):

In the discussions, Mr. Happenny explained that after EASA created their regulatory 

requirements and guidelines (CS-25, Amendment 4, December 2007), industry developed 

additional standards and guidelines that provide useful information and assist in 

demonstrating compliance to the FAA regulatory requirements. For example, SAE 

Aerospace Standard (AS) 6453 specifies the design and performance criteria and testing 

methods of fire containment covers (FCCs) for carriage of cargo on the main deck of 

transport category airplanes. In response, FAA developed Technical Standard Order (TSO) 

TSO-C203C, which includes additional requirements for FCCs. While the current EASA 

regulatory requirements and guidance in their AMCs lack these references, EASA agreed 

that including these details in the FAA rule and guidance material was appropriate in the 

harmonization effort.

3. Regulatory text differences between EASA CS 25.851(b) and FAA 25.851(b):

Mr. Happenny discussed with EASA the FAA’s omission of the word “anywhere” from the 

first sentence of § 25.851(b)(2):

The capacity of each required built-in fire extinguishing system must be adequate for any 

fire likely to occur anywhere in the compartment where used, considering the volume of 

the compartment and the ventilation rate.

Mr. Happenny explained that this word was redundant and unnecessary because, if the 

capacity of a built-in fire extinguishing system must be adequate “for any fire likely to occur 

in the compartment” (the existing rules), it must already be adequate for a fire likely to occur 

“anywhere” in the compartment. However, in its rule, the FAA used the term “anywhere” in 

an additional sentence that is not in EASA’s corresponding rule: 

For purposes of this paragraph, a system is adequate if there is sufficient quantity of agent 

to extinguish the fire or suppress the fire anywhere baggage or cargo is placed within the 

cargo compartment for the duration required to land and evacuate the airplane.

Mr. Happenny explained to his counterparts that to ensure enforceability, the FAA included 

that clarifying sentence in the rule text. The FAA and EASA reached a consensus that, while 

these changes differ from the EASA rule, the purpose and effect of the EASA rule is met by 

the FAA rule, so the FAA rule is still harmonized with its EASA corresponding rule.

4. The 52-inch reach discussed in AC 25.857-X:

EASA had adopted the Cargo Standards Harmonization Working Group recommendation 

that included an estimate of the size of a Class B cargo compartment that would meet the 
intent that a crewmember be able to reach any part of the compartment in the event of a fire.

This estimate was based on the approximate reach of a 95th percentile male and that the 

outline of any compartment, viewed from above, should fit within a vertical cylinder of 

radius 52 inches (132 cm) measured from the centerline of the access door or hatch. This 52-

inch radius also included consideration of the effective controlled distance from the discharge 

of a hand fire extinguisher to the burning item. In the discussions listed at the beginning of 

this record, Mr. Happenny explained the FAA’s position that the use of a 95th percentile male 

is not realistic because many crewmembers, including flight attendants, are female and have 

a smaller reach. A 50th percentile female has a reach of 28.96 inches (~74 cm), and the FAA 

believed that this is a reasonable value to use. However, the FAA considers the effective 

controlled distance from the discharge of a hand fire extinguisher to the burning item to be on 

average about 23 inches. The consensus reached by Mr. Happenny and his counterparts was 

that regardless of whether the 52-inch reach was based on a 95th percentile male or a 50th

percentile female, the effective reach of 52 inches is considered to be nominally correct when

consideration is given for variations in effective control of the discharge of a hand fire 

extinguisher, service experience of Class B cargo compartments, and the benefits of 

harmonization.

5. Non-significant differences in the advisory material provided in AC 25.851-X and 

AC 25.857-X and EASA’s AMC 25.851(a)(2), AMC 25.851(b), AMC 25.851(c):

Mr. Happenny discussed with EASA the differences between the FAA’s proposed ACs on 

this subject and EASA’s AMCs. The ACs will be very similar to the AMCs, but will include 

additional information on the use of non-halon fire extinguishing/suppression agents, agent 

simulants in lieu of discharging halon during certification tests, fire resistant unit load 

devices (ULDs) in Class F cargo compartments, and fire containment covers (FCC) on ULDs 

and/or bulk cargo pallets in Class F cargo compartments. The consensus between Mr. 

Happenny and his EASA counterparts was that this additional information does not create 

any regulatory differences and reflects developments in industry standards and the results of 

testing.