[4910-13]

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. 92-NM-67-AD; Amendment 39-8547; AD 93-07-15]

Airworthiness Directives; Boeing Models 707, 727, 737, 747, and 757 Series Airplanes; 

and McDonnell Douglas Models DC-8, DC-9, and DC-10 Series Airplanes 

AGENCY: Federal Aviation Administration, DOT. 

ACTION: Final rule. 

SUMMARY: This amendment supersedes an existing airworthiness directive (AD), 

applicable to Boeing and McDonnell Douglas airplanes, that currently requires certain 

operational and equipment changes and design modifications to be accomplished to 

maximize fire detection and protection in main deck cargo compartments. The existing 

rule was issued based on the FAA's determination that the existing Class B cargo 

compartment firefighting procedures and fire protection features were inadequate, and 

could result in the loss of an airplane. This amendment requires certain design 

modifications and operational requirements to ensure an adequate level of safety on 

airplanes with Class B cargo compartments. This amendment is prompted by comments 

from the public and additional information received after issuance of the existing AD. 

EFFECTIVE DATE: May 2, 1993.

ADDRESSES: Information pertaining to this AD may be examined at the Federal 

Aviation Administration (FAA), Transport Airplane Directorate,

Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles 

Aircraft Certification Office, Transport Airplane Directorate, 3229 E. Spring Street, Long 

Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., 

suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: For information concerning Boeing 

airplanes, contact Ms. Susan Letcher, Aerospace Engineer, Seattle Aircraft Certification 

Office, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 

Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 

(206) 227-2670, fax (206) 227-1181. For information concerning McDonnell Douglas 

airplanes, contact 

Mr. Kevin Kuniyoshi, Aerospace Engineer, Los Angeles Aircraft Certification Office, 

Mechanical/Environmental and Crashworthiness Section, ANM-131L, FAA, Transport 

Airplane Directorate, 3229 E. Spring Street, Long Beach, California 90806-2425; 

telephone (310) 988-5337; fax (310) 988-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 

Aviation Regulations by superseding AD 91-10-02, Amendment 39-6986 (56 FR 20529, 

May 6, 1991), which is applicable to various Boeing and McDonnell Douglas airplanes, 

was published in the Federal Register on August 17, 1992 (57 FR 36918). The action 

proposed to require certain design modifications and operational requirements to ensure an 

adequate level of safety on airplanes with Class B cargo compartments. 

 Interested persons have been afforded an opportunity to participate in the making of 

this amendment. Due consideration has been given to the comments received. 

Response to Commenters

One commenter supports the proposal, especially the decision to delete the 
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previous requirement for use of a firefighter. This commenter considers that, although 

conversion to the Class C cargo compartment configuration will provide the greatest level 

of safety, the options proposed by the FAA in this rulemaking action provide a more 

acceptable and practical choice for the affected industry.

Several commenters are concerned about the worldwide impact of the proposed 

rule. These commenters recommend that the FAA coordinate the proposal with the Joint 

Aviation Authorities (JAA) and Transport Canada Aviation. The FAA notes that it has 

worked, and will continue to work, very closely with these organizations in the 

development of rulemaking concerning combi-configured ("Combi") airplanes and their 

operations.

Two commenters recommend that a separate AD be issued that would apply only to 

narrow-body airplanes. A separate AD could take into account all of the differences 

between narrow-body and wide-body operations, and specify only those requirements that 

specifically pertain to narrow-body airplane configurations and operations. Such an 

action also would make for an AD that would be considerably easier to read. The FAA 

disagrees. The threat of an uncontrolled fire is equivalent for both narrow-body and 

wide-body airplanes. The FAA recognizes that the solutions may differ based on size of 

the airplane and airline route structure; however, it is impractical to address each operator's 

unique circumstance in this AD or through a collection of AD's, due to the varied airplane 

types and route structures. 

The options offered in this rule apply equally to both narrow-body and wide-body

airplanes. Operators who need to tailor certain of the requirements for various operations 

may apply for alternative methods of compliance with the rule, under the provisions of 

paragraph (d).

One commenter requests that the rule be revised to require specifically that safety 

equipment be located in the passenger cabin, outside of the cargo compartment. The FAA 

agrees with the commenter's suggestion that certain equipment be located outside of the 

cargo compartment, but does not consider that a revision to the rule is necessary. 

Paragraph (b) of the rule does require that protective garments and protective breathing 

equipment (PBE) be located outside of the cargo compartment; additionally, paragraph (a) 

of the rule requires that portable fire extinguishers be located such that they are readily 

available for use in the cargo compartment. In fact, the FAA previously has required that, 

for compliance with AD 89-18-12 R1 [Amendment 39-6557 (55 FR 11163, March 27, 

1990)], a portion of the extinguishers must be located outside of the cargo compartment for 

ready access. The FAA will continue to require that a number of the extinguishers be 

located in the passenger compartment, unless adequate data can be submitted to support a 

different location.

 Several commenters note, and agree with, the FAA's previous acceptance of certain 

existing smoke detection systems in meeting the intent of the "one-minute detection" 

requirement of the rule. (The intent of this requirement was explained in detail in the 

preamble to the notice.) The FAA points out, however, that operators should be aware 

that acceptance of these systems for the purposes of this rule does not necessarily constitute 

compliance with FAR 25.858 ("Cargo compartment fire detection systems"). 

Two commenters question the differences in wording appearing in the proposed 

rule concerning the personnel required to perform the preflight inspection. These 
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commenters point out that paragraph (a)(1) would require that a "flight deck crewmember" 

perform the inspection, whereas paragraphs (b)(3)(ix) and (b)(4)(xi) would require that a 

"crewmember" perform the inspection. Because of these differences, operators would be 

required to make two different revisions to the Airplane Fight Manual (AFM). One of the 

commenters requests that paragraph (a)(1) be modified to allow a "crewmember," rather 

than a "flight deck crewmember," to perform the preflight inspection. The FAA does not 

concur that a change in the wording of the rule is warranted. At this point, the requirement 

of paragraph (a)(1) should have been implemented on existing airplanes by May 3, 1991, in 

accordance with the existing rule, AD 91-10-02. Although compliance with paragraph (b) 

is not required for several years after the effective date of this final rule, operators have the 

option to comply directly with individual portions of paragraph (b) prior to the compliance 

date. Operators should recognize that compliance with the paragraph (b)(3)(ix) or 

(b)(4)(xi) requirement supersedes the paragraph (a)(1) requirement. In addition, the 

paragraph (b) requirement is considered "relieving," as it allows any crewmember to 

perform the preflight inspection, whereas paragraph (a) allows only a flight deck 

crewmember to perform the inspection. 

Another commenter states that the preflight inspection requirements of proposed 

paragraphs (a)(1), (b)(3)(ix), and (b)(4)(xi) would be more appropriately placed in the 

Normal Procedures section (Section 3) of the AFM, rather than in the Limitations section. 

This commenter considers that it is inappropriate to put this information in the Limitations 

section because it does not meet the intent of FAR 25.1583 ("Operating limitations"). The 

commenter states that these requirements of the rule also restrict the operators in the 

development of their operations manuals. The FAA does not concur. The preflight 

inspection is appropriate in the Limitations section of the AFM because it is a flight crew 

duty, in accordance with FAR 25.1583(d). Although paragraphs (b)(3)(ix) and (b)(4)(xi) 

allow any crewmember to perform the inspection, the pilot remains the individual 

responsible for safe operation of the airplane in accordance with FAR 91.3 

("Responsibility and authority of the pilot in command") and, therefore, is responsible for 

ensuring that the preflight inspection is properly conducted. Specific reminders to this 

effect are included in the final rule as Notes 1, 2, and 3. 

Another commenter requests that proposed paragraphs (a)(1), (b)(3)(ix), and 

(b)(4)(xi) be revised to allow insertion of a copy of the AD into the AFM as an option to 

revising the AFM to reflect the preflight inspection requirement. The FAA does not 

concur. Compliance with paragraph (b) of the rule requires additional modifications to 

the flight manual, depending upon the option selected. The necessary revisions to the 

flight manual to accommodate the new equipment and procedures could not be adequately 

communicated by inserting a copy of the AD in the AFM. 

One commenter requests that proposed paragraph (a)(2)(iv) be revised to delete the 

requirement for two-sided access to loaded pallets or containers. Another commenter 

requests that the placard that would be required by the same paragraph be revised to 

consider "the top and one side" of a loaded pallet/container as equivalent to "two-sided 

access" for airplanes such as the Boeing Model 727 and Model 737. The FAA does not 

concur with the request to delete the requirement. The FAA considers two-sided access to 

be an important requirement to ensure that adequate access is available for the remote 

instance when manual firefighting is required. The FAA does consider that the top and 
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one side of a loaded pallet/container could be acceptable as two-sided access in certain 

cases, based on size of the airplane, nature of the airline operation, and incorporated fire 

protection features; however, the FAA does not concur that such a provision should apply 

universally to all airplanes. Insertion of such a provision in the rule is impractical. In the 

past, the FAA has allowed the top and one side of palleted cargo and containers to be 

considered two-sided access as an alternative method of compliance with AD 89-18-12 R1. 

The FAA will continue to recognize that acceptable alternative methods of compliance that 

allow such a provision could be acceptable on a case-by-case basis; operators may apply 

for the use of such methods under the provisions of paragraph (d) of the final rule.

 Several commenters request that the proposed 30-month compliance period for the

requirements of paragraph (b) be extended. The commenters indicate that modification 

kits for the Boeing Model 747-100, 747-200 and 747-300 series airplanes will not be 

available from the manufacturer until August 1993, at which time the kits will be produced 

at a rate of only three per month. Likewise, modification kits for the Boeing Model 

747-400 series airplanes will not be available until August 1994. In light of this schedule, 

the commenters request that the compliance period be extended to allow 5 years after kit 

availability for airlines to schedule modification of their airplanes; this would amount to a 

3- to 4-year extension beyond the proposed 30-month compliance period. One 

commenter also requests more flexibility in the schedule for modification implementation 

on Boeing Model 747-400 series airplanes because of related improvements that have 

already been implemented on these airplanes. Upon review of this new data provided by

the commenters, the FAA concurs that additional time can be provided for compliance. 

The proposed 30-month compliance period was based on initial estimates of the time 

required to design, produce, and install modifications on Boeing Model 747 series Combi 

airplanes, for which the required modifications were considered to be the most extensive. 

Based on the production schedule for the modification kit for these as well as other 

airplanes, the FAA now considers that the proposed 30-month compliance period is 

insufficient. The FAA does not concur, however, with the request for the extensive delays 

suggested by the commenters. The FAA has determined that an additional 12 months will 

provide sufficient time for compliance without adversely affecting safety. The final rule 

has been revised to reflect this.

 Several commenters state that the option of covering all cargo, in accordance with 

proposed paragraph (b)(3), is not practical. One commenter states that certain 

noncombustible items, such as animals, vehicles, and steel for oil rigs, are not fire hazards 

and should not be required to be covered. One commenter suggests that the rule require 

that only material meeting certain hazardous material criteria be required to be covered. 

The FAA concurs that some noncombustible cargo may not need to be covered, provided 

that it is not packed in or covered with combustible packing materials. However, these 

situations must be considered on a case-by-case basis. Under the provisions of paragraph 

(d) of the final rule, operators can request to use an alternative method of compliance with 

paragraph (b)(3) when certain cargo types are carried.

 One commenter states that the types of covers that would be required by proposed 

paragraph (b)(3)(i)(A) are hard to find. This commenter requests that the rule be delayed 

until an adequate number of covers are developed and manufactured. The FAA does not 

concur that delay of the rule is warranted. The FAA recognizes that FAA-approved cargo 
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covers are not readily available at this time. However, the compliance time for the 

relevant portion of the final rule provides adequate time to develop and manufacture covers 

or containers that comply with this requirement. 

 One commenter recommends that aural and visual warnings that would be required by

proposed paragraph (b)(3) be limited to the flight deck in order to prevent unnecessary

alarm to the passengers, particularly in the case of false alarms. The FAA disagrees. 

Although the FAA acknowledges that warning signals may alarm passengers, the FAA 

considers that the warning signal in the passenger compartment is necessary in order to 

alert the flight attendants so that procedures for responding to alarms can be initiated. 

 Several commenters disagree with the quantities of PBE that would be required by 

proposed paragraphs (b)(3)(viii)(B) and (b)(4)(x)(B). Several commenters submitted data 

that would support specific reductions in the PBE requirement. The FAA agrees that, in 

certain cases, this quantity could be reduced without adversely impacting safety. The 

quantity of PBE as proposed was based on a 120-minute diversion scenario; the proposed 

amount was considered to be warranted in order to allow sufficient PBE for one person to 

monitor the fire continuously throughout the diversion, and an additional 30 minutes of 

PBE for a second person. The FAA does not consider that it is necessary to revise the 

specific requirements in paragraphs (b)(3)(viii)(B) and (b)(4)(x)(B), however. The FAA 

may consider accepting requests for the use of reduced quantities of PBE in certain 

operations, based on the fire protection features provided and maximum diversion times 

expected. Under the provisions of paragraph (d) of the final rule, operators may request 

such reductions through applications for alternative methods of compliance.

 Several commenters request the rule be revised to reduce the required quantity of 

halon extinguishant, water extinguishers, and protective garments. In particular, one 

commenter recommends that proposed paragraph (b)(3) of the rule specifically not require 

water extinguishers. This commenter notes that it would be unrealistic to require water to 

be applied directly to the burning material, especially since the cargo would be under a 

cover or in a container. The commenter further notes that water runoff could also damage 

the electrical systems in the cargo compartment. The FAA concurs that the number of 

halon and water extinguishers could be reduced on a case-by-case basis, depending on the 

method of compliance selected and individual airline operational considerations. 

Operators who can adequately justify such reductions may request such relief through 

alternative methods of compliance, in accordance with paragraph (d) of the rule. The 

FAA does not concur, however, with a reduction in the requirement for two sets of 

protective garments. The FAA considers that this number of protective garments is 

essential in the event that manual intervention becomes necessary and a second person is 

required to assist in firefighting duties.

 One commenter requests that the rule be revised to provide relief from some of the 

requirements of paragraph (b)(3), including the illumination, smoke barrier, crew training, 

and flight test requirements. The FAA cannot concur since this commenter provided no 

data to substantiate the request. Under the provisions of paragraph (d) of the final rule, 

any operator who requires "relief" of any type from the requirements of this rule has the 

opportunity to apply for the use of an alternative method, provided that adequate 

supporting data to justify such a request is submitted with the application.

One commenter points out that proposed paragraph (b)(3)(iv)(B) should be 
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corrected to read ".05 foot candle," rather than "5 foot candles." The FAA concurs. The 

same error occurred in paragraph (b)(4)(vi)(B). The final rule has been corrected to 

reflect this. 

Two commenters request clarification of proposed paragraph (b)(4)(v), which 

would require operators to demonstrate that critical systems in the cargo compartment are 

adequately protected from fire. These commenters point out that, in the preamble to the 

notice, the FAA stated that it had originally intended to allow crewmembers first to 

confirm the presence of fire on alarm by looking into, and possibly entering, the cargo 

compartment prior to release of the halon. (This procedure was considered primarily in 

recognition of the fact that the likelihood of a false alarm is considerably higher than that of 

a real fire.) Because this act of "manually" confirming the fire would delay release of the 

halon, the proposed rule would require that operators demonstrate that critical systems in 

the cargo compartment would not be compromised in that period of time prior to halon 

release and effectiveness. However, the FAA also indicated that automatic release of 

halon on alarm, without manual confirmation, might be required to compensate for this if 

adequate protection could not be demonstrated. Regardless of the procedure for halon 

release (automatic discharge or confirmation), adequate protection of critical systems in 

the cargo compartment must be validated.

In view of this, one commenter requests that the automatic release of halon 

procedure not be permitted, since false alarms often occur when carrying cargo such as 

animals, vegetables, and flowers. In response to this commenter's concern, the FAA 

recognizes that the likelihood of a false alarm is much greater than that of a real fire. The 

FAA considers that automatic halon release would be required only if adequate protection 

could not be demonstrated to ensure timely release of halon before damage to critical 

systems occurs. If adequate protection of these systems is demonstrated, automatic 

release would not be required.

Along this same line, another commenter questions whether the FAA would 

consider an acceptable "automatic" halon release procedure to be "the release of halon 

immediately by crew procedure upon smoke detection indication and confirmation." The 

FAA responds to this commenter by indicating that it currently does not consider manual 

release of halon on alarm to constitute "automatic" release. However, if adequate 

supporting data were submitted to the FAA to demonstrate that manual release of halon by 

crew procedure would not cause a delay in halon discharge and would not result in damage 

to critical systems, the FAA would be willing to consider it as an alternative method of 

compliance with the relative portion of the rule. Operators interested in using such an 

alternative method should review the provisions of paragraph (d) of the final rule. 

One commenter requests that the rule be revised to provide an additional option that 

would allow the halon protection system to be reduced to 60 minutes, provided that the 

maximum diversion was always within 90 minutes. Proposed paragraph (b)(4) offers 

operators an option to install only a 90-minute halon protection system. The FAA does 

not concur. The 90-minute halon system, along with the associated required design and 

operational changes, was intended to provide protection for diversions up to 120 minutes. 

In developing the rule, the FAA surveyed Combi operators worldwide; based on data 

received from this survey, the FAA determined that only 10% of Combi flight time would 

be beyond 90 minutes of a suitable landing in the event of a fire. Therefore, a 90-minute 
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halon system would provide full halon coverage through the diversion in most cases. 

Conversely, almost 30% of Combi flight time would be beyond 60 minutes of a suitable 

landing, leading to a much higher probability that diversions will not have full halon 

coverage. The commenter submitted no specific operational data to support the reduction 

in halon proposed. However, under the provisions of paragraph (d) of the final rule, 

operators may request the use of an alternative method of compliance with the rule, 

provided that data submitted adequately supports the request.

Several other commenters recommend that an additional option be provided in the 

rule to allow for the installation of a 60-minute halon system, provided that the crew is 

trained in accordance with the firefighter requirements specified by the Joint Aviation 

Authorities (JAA). The FAA does not concur. As previously stated, a survey of current 

Combi operations has shown that almost 30% of Combi flight time would be more than 60 

minutes from a suitable landing. The FAA has previously determined that manual 

firefighting is ineffective and should only be attempted as a last resort; therefore, additional 

training to fight fires would not sufficiently offset the reduced safety of a 60-minute halon 

system. 

 One commenter requests that the rule be revised to delete the special illumination 

criteria specified in proposed paragraph (b)(4)(vi). The FAA disagrees. A certain level 

of lighting is required for confirming the presence of a fire in the cargo compartment, and 

for monitoring the compartment after an alarm. Some existing lighting systems may be 

adequate to meet the intent of the requirement. Operators interested in using existing 

lighting may request approval of the use of an alternative method of compliance with the 

rule, in accordance with paragraph (d) of the final rule.

 One commenter requested relief from the illumination requirement of proposed 

paragraph (b)(3)(iv) for narrow-body airplanes. Because of the configuration of the cargo 

compartment on narrow-body airplanes, the only pathway in the compartment is fore and 

aft along the left sidewall of the compartment; in all configurations, this pathway is 

"defined" by the cargo and containers. The commenter states that, even with reduced 

visibility, a crewmember monitoring the compartment could easily navigate by touch. 

Further, additional illumination is provided during daylight hours from windows with 

raised shades. The FAA does not concur with the commenter's request. The FAA has 

determined that a certain level of lighting is required for adequately monitoring the cargo 

compartment. The FAA does acknowledge, however, that some existing lighting on 

certain airplane configurations may be acceptable to meet the intent of the rule. Operators 

who consider that the current configuration of their airplanes meet this intent, may supply 

substantiating data to the FAA through the alternative method of compliance provisions of 

paragraph (d) of the final rule.

 One commenter points out that paragraph (b)(4)(ii) should reference Amendment 

"25-54," rather than Amendment "25-4." The FAA acknowledges this publication error. 

The final rule has been revised to reflect the correct amendment number.

 In addition, another publication error was identified in paragraph (b)(4)(x)(B). The 

Technical Standard Order (TSO) referenced in that paragraph should be TSO "C-116," 

rather than "C-16." The final rule has been corrected to reflect this.

 After careful review of the available data, including the comments noted above, the 

FAA has determined that air safety and the public interest require the adoption of the rule 
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with the changes previously described. The FAA has determined that these changes will 

neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact

 There are approximately 278 Boeing Models 707, 727, 737, 747, and 757 series 

airplanes and 124 McDonnell Douglas Model DC-8, DC-9, and DC-10 series airplanes of 

the affected design in the worldwide fleet. It is estimated that approximately 80 Boeing 

Model 707, 727, 737, 747, and 757 series airplanes, and 79 McDonnell Douglas Model 

DC-8, DC-9, and DC-10 series airplanes, of U.S. registry have been certificated to operate 

with a Class B main deck cargo compartment. Many of these airplanes are operated 

permanently in the all-passenger configuration and, therefore, are not affected by this rule. 

Approximately 40 of these airplanes are currently operated by U.S. operators in the mixed 

cargo/passenger configuration and are affected by this amendment.

The design alternative selected by the operator and the type of airplane will have a 

significant impact on the cost of complying with this AD. The highest cost option is 

expected to be the conversion to a Class C compartment, as defined in paragraph (b)(1) of 

this proposal. A conservative cost estimate for incorporating the extended halon option 

into Boeing Model 747 airplanes, based upon costs of required materials, labor, and 

testing, is $2,000,000 per airplane. A conservative estimate for incorporating the 

blanket/container option on Boeing Model 747 airplanes, based upon the costs of required 

materials, labor, and testing, is $200,000.

The FAA is not aware of any U.S. Model 747 Combi operators. Most 

U.S.-registered Combis are Boeing Models 727 and 737 airplanes operated in Alaska. 

The FAA previously has granted these operators alternative methods of compliance with 

AD 89-18-12 R1. These alternative methods of compliance are acceptable to meet the 

intent of this amendment as well. Therefore, this AD should incur no additional cost on U.S 

operators.

Regulatory Impact

 The regulations adopted herein will not have substantial direct effects on the States, 

on the relationship between the national government and the States, or on the distribution 

of power and responsibilities among the various levels of government. Therefore, in 

accordance with Executive Order 12612, it is determined that this final rule does not have 

sufficient federalism implications to warrant the preparation of a Federalism Assessment.

 For the reasons discussed above, I certify that this action (1) is not a "major rule" 

under Executive Order 12291; (2) is not a "significant rule" under DOT Regulatory

Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 

significant economic impact, positive or negative, on a substantial number of small entities 

under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared 

for this action and it is contained in the Rules Docket. A copy of it may be obtained from 

the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39

 Air transportation, Aircraft, Aviation safety, Safety
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ADOPTION OF THE AMENDMENT 

 Accordingly, pursuant to the authority delegated to me by the Administrator, the 

Federal Aviation Administration amends 14 CFR part 39 of the Federal Aviation 

Regulations as follows: 

PART 39 - AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. 

Section 39.13 - [AMENDED]

 2. Section 39.13 is amended by removing Amendment 39-6986 (56 FR 20529, May

6, 1991) and by adding a new airworthiness directive (AD), amendment 39-8547, to read as 

follows: 

93-07-15 BOEING AND MCDONNELL DOUGLAS: Amendment 39-8547, Docket 

No. 92-NM-67-AD. Supersedes AD 91-10-02, Amendment 39-6986.

 Applicability: Boeing Models 707, 727, 737, 747, and 757 series airplanes and 

McDonnell Douglas Models DC-8, DC-9, and DC-10 series airplanes; equipped with a 

main deck Class B cargo compartment, as defined by Federal Aviation Regulations (FAR) 

25.857(b) or its predecessors, with a volume exceeding 200 cubic feet; certificated in any 

category. 

Compliance: Required as indicated, unless accomplished previously. 

To minimize the hazard associated with a main deck Class B cargo compartment 

fire, accomplish the following: 

(a) Within one year after May 3, 1990 (the effective date of Amendment 39-6557, 

AD 89-18-12 R1), or prior to carrying cargo in a Class B cargo compartment, whichever 

occurs later, accomplish the following in accordance with the appropriate technical data 

approved by the Manager, Seattle Aircraft Certification Office (for affected Boeing series 

airplanes), FAA, Transport Airplane Directorate; or the Manager, Los Angeles Aircraft 

Certification Office (for affected McDonnell Douglas series airplanes), FAA, Transport 

Airplane Directorate: 

 (1) Revise the Limitations Section of the FAA-approved Airplane Flight Manual 

(AFM) to include the following:

"FOR EACH FLIGHT IN WHICH CARGO IS TRANSPORTED IN THE 

CLASS B CARGO COMPARTMENT:

Prior to flight, a flight deck crewmember must make a visual inspection 

throughout the Class B cargo compartment to verify access to cargo and the general fire

security of the compartment after the cargo door is closed and secured." 

NOTE 1: This visual inspection is in no manner intended to relieve the pilot of 

his/her responsibility to ensure safe operation of the airplane, as required by FAR 91.3.

(2) Incorporate the following systems and equipment:

(i) Provide a minimum of 48 lbs. Halon 1211 fire extinguishant, or its equivalent, 

in portable fire extinguisher bottles readily available for use in the cargo compartment. At 

least two bottles must be a minimum of 16 lb. capacity. 

(ii) Provide at least two Underwriters Laboratories (UL)2A (2-1/2 gallon) rated 

water portable fire extinguishers, or its equivalent, adjacent to the cargo compartment 

entrance for use in the compartment. 

(iii) Provide a means for two-way communication between the flight deck and the 
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interior of the cargo compartment.

(iv) Install placards in conspicuous place(s) within the cargo compartment clearly 

defining the cargo loading envelope and limitations that provide sufficient access of 

sufficient width for firefighting along the entire length of at least two sides of a loaded 

pallet or container. Amend the appropriate Weight and Balance and loading instructions 

by description and diagrams to include this information.

(3) Incorporate the following systems and equipment:

(i) Provide appropriate protective garments stored adjacent to the cargo 

compartment entrance.

(ii) Provide a minimum of 30 minutes of protective breathing. This equipment 

must meet the requirements of Technical Standard Order (TSO) C-116, Action Notice 

8150.2A, or equivalent, and be stored adjacent to the cargo compartment entrance. 

(b) Within 42 months after the effective date of this AD, or prior to carrying cargo 

in a Class B cargo compartment, whichever occurs later, accomplish the requirements of 

either paragraph (b)(1), (b)(2), (b)(3), or (b)(4) of this AD:

(1) OPTION 1: Modify the Class B cargo compartment to comply with the 

requirements for a Class C cargo compartment, as defined in FAR 25.855 (Amdt. 25-60), 

25.857(c), and 25.858 (Amdt. 25-54).

(2) OPTION 2: Modify all main deck Class B cargo compartments to require the 

following placard installed in conspicuous locations approved by the Manager, Seattle 

Aircraft Certification Office, FAA, Transport Airplane Directorate (for affected Boeing 

series airplanes), or the Manager, Los Angeles Aircraft Certification Office, FAA, 

Transport Airplane Directorate (for affected McDonnell Douglas series airplanes), 

throughout the compartment:

"Cargo carried in this compartment must be loaded in an approved flame 

penetration-resistant container meeting the requirements of FAR 25.857(c) 

with ceiling and sidewall liners and floor panels that meet the requirements 

of FAR 25, Appendix F, Part III, (Amdt. 25-60)."

(3) OPTION 3: In addition to the requirements of paragraph (a)(2) of this AD, 

accomplish the following in accordance with technical data approved by the Manager, 

Seattle Aircraft Certification Office (for affected Boeing series airplanes), or the Manager, 

Los Angeles Aircraft Certification Office (for affected McDonnell Douglas series 

airplanes):

(i) Carriage of all cargo in Class B cargo compartments must meet the 

requirements of either paragraph (b)(3)(i)(A) or (b)(3)(i)(B) of this AD: 

(A) Cover cargo with fire containment covers.

(B) Carry cargo in fire containment containers.

(ii) Provide a smoke or fire detection system in the Class B cargo compartment 

that meets the requirements of FAR 25.858 (Amdt. 25-54) and also provides an aural and 

visual warning to the crewmembers in the passenger compartment. 

(iii) Provide a barrier between the Class B cargo compartment and the passenger 

compartment to prevent the penetration of smoke or flames from the cargo compartment 

into the passenger compartment. The barrier must extend from the cargo compartment 

floor to the upper crown area of the fuselage, and from the right sidewall to the left sidewall 

of the cargo compartment, completely isolating the cargo compartment from the passenger 
11

compartment. The barrier and associated seals/interfaces must meet the requirements of 

FAR 25, Appendix F, Part III (Amdt. 25-60). 

(iv) Provide illumination of the Class B cargo compartment as specified in 

paragraphs (b)(3)(iv)(A) and (b)(3)(iv)(B) of this AD:

(A) General area illumination of the cargo with an average illumination of 0.1 

foot-candle measured at 40-inch intervals both at one-half the pallet or container height, 

and at the full pallet or container height, or as approved by the FAA. 

(B) Illumination of the longitudinal access pathways, required by paragraph 

(a)(2)(iv) of this AD, with an average illumination of .05 foot-candle when measured at 

40-inch intervals along a line that is within 2 inches of and parallel to the floor centered on 

the pathway, or illumination under visibility conditions likely to occur in the cargo 

compartment in the event of a fire.

(v) Establish FAA-approved procedures and training as specified in paragraphs 

(b)(3)(v)(A) and (b)(3)(v)(B) of this AD:

(A) Use and maintenance of items required by paragraph (b)(3)(i).

(B) Responding to alarms, and monitoring and controlling Class B cargo 

compartment fires. 

(vi) Provide a viewport into the Class B cargo compartment from the passenger 

compartment. The viewport must be located such that a crewmember can readily identify 

the overall smoke conditions in the compartment prior to entering it.

(vii) Demonstrate the following features and functions, specified in paragraphs 

(b)(3)(vii)(A), (b)(3)(vii)(B), and (b)(3)(vii)(C) of this AD:

(A) Smoke or Fire Detection System, required by paragraph (b)(3)(ii) of this AD, 

by flight test.

(B) Prevention of smoke penetration into occupied compartments [refer to FAR 

25.857(b)(2) and 25.855(e)(2)], by flight test.

(C) Cargo accessibility, as specified in paragraph (a)(2)(iv) of this AD.

(viii) Provide the following systems and equipment:

(A) Provide appropriate protective garments for two persons stored in the 

passenger compartment, adjacent to the Class B cargo compartment entrance.

(B) Provide a minimum of 120 minutes of protective breathing for one person, 

and an additional 30 minutes of protective breathing for an additional person. This 

equipment must meet the requirements of Technical Standard Order (TSO) C-116, Action 

Notice 8150.2A, or equivalent, and at least 30 minutes of the total protective breathing 

must be stored adjacent to the Class B cargo compartment entrance. All protective 

breathing equipment must be located outside the cargo compartment. 

(ix) Revise the Limitations Section of the FAA-approved Airplane Flight Manual 

(AFM) to include the following:

"FOR EACH FLIGHT IN WHICH CARGO IS TRANSPORTED IN THE CLASS

B CARGO COMPARTMENT:

Prior to flight, a crewmember who is assigned firefighting responsibility for the 

flight must make a visual inspection throughout the Class B cargo compartment for 

familiarization, after the cargo door is closed and secured."

NOTE 2: This visual inspection is in no manner intended to relieve the pilot of 

his/her responsibility to ensure safe operation of the airplane, as required by FAR 91.3. 
12

(4) OPTION 4: In addition to the requirements of paragraph (a)(2) of this AD, 

accomplish the following in accordance with technical data approved by the Manager, 

Seattle Aircraft Certification Office (for affected Boeing series airplanes), or the Manager, 

Los Angeles Aircraft Certification Office (for affected McDonnell Douglas series 

airplanes):

(i) Provide a cargo compartment fire extinguishing system in the Class B cargo 

compartment that provides an initial fire extinguishant concentration of at least 5 percent of 

the empty compartment volume of Halon 1301 or equivalent, and a fire suppression 

extinguishant concentration of at least 3 percent of the empty compartment volume of 

Halon 1301 or equivalent, for a period of time not less than 90 minutes.

(ii) Provide a smoke or fire detection system in the Class B cargo compartment 

that meets the requirements of FAR 25.858 (Amdt. 25-54) and also provides an aural and 

visual warning to the crewmembers in the passenger compartment.

(iii) Provide a means from the flight deck to shut off ventilation system inflow to 

the Class B cargo compartment.

(iv) Provide a barrier between the Class B cargo compartment and the passenger 

compartment to prevent the penetration of smoke or flames from the cargo compartment 

into the passenger compartment. The barrier must extend from the cargo compartment 

floor to the upper crown area of the fuselage, and from the right sidewall to the left sidewall 

of the cargo compartment, completely isolating the cargo compartment from the passenger 

compartment. The barrier and associated seals/interfaces must meet the requirements of 

FAR 25, Appendix F, Part III (Amdt. 25-60).

(v) Provide appropriate protection of the cockpit voice and flight data recorders, 

and all systems or components required for safe flight and landing of the airplane, unless it 

can be demonstrated that these systems are not susceptible to damage in the event of a fire 

in the Class B cargo compartment.

(vi) Provide illumination of the Class B cargo compartment as specified in 

paragraphs (b)(4)(vi)(A) and (b)(4)(vi)(B) of this AD:

(A) General area illumination of the cargo with an average illumination of 0.1 

foot-candle measured at 40-inch intervals both at one-half the pallet or container height, 

and at the full pallet or container height, or as approved by the FAA.

(B) Illumination of the longitudinal access pathways, required by paragraph 

(a)(2)(iv) of this AD, with an average illumination of .05 foot-candle when measured at 

40-inch intervals along a line that is within 2 inches of and parallel to the floor centered on 

the pathway, or illumination under visibility conditions likely to occur in the cargo 

compartment in the event of a fire, as approved by the FAA. 

(vii) Establish FAA-approved procedures and training for responding to alarms, 

and monitoring and controlling cargo compartment fires.

(viii) Provide a viewport into the Class B cargo compartment from the passenger 

compartment. The viewport must be located such that a crewmember can readily identify 

the overall smoke conditions in the compartment prior to entering it.

(ix) Demonstrate the following features and functions:

(A) Fire extinguishant concentration, required by paragraph (b)(4)(i) of this AD, 

by flight test.

(B) Smoke or fire detection system, required by paragraph (b)(4)(ii) of this AD, 
13

by flight test.

(C) Prevention of smoke penetration into occupied compartments [refer to FAR 

25.857(b)2 and 25.855(e)2], demonstrated by flight test. 

(D) Cargo accessibility, as specified in paragraph (a)(2)(iv) of this AD.

(x) Provide the following systems and equipment:

(A) Provide appropriate protective garments for two persons stored in the 

passenger compartment, adjacent to the Class B cargo compartment entrance.

(B) Provide a minimum of 120 minutes of protective breathing for one person, 

and an additional 30 minutes of protective breathing for an additional person. This 

equipment must meet the requirements of Technical Standard Order (TSO) C-116, Action 

Notice 8150.2A, or equivalent, and at least 30 minutes of the total protective breathing 

must be stored adjacent to the Class B cargo compartment entrance. All protective 

breathing equipment must be located outside the cargo compartment. 

(xi) Revise the Limitations Section of the FAA-approved Airplane Flight Manual 

(AFM) to include the following statement:

"FOR EACH FLIGHT IN WHICH CARGO IS TRANSPORTED IN THE CLASS 

B CARGO COMPARTMENT:

Prior to flight, a crewmember who is assigned firefighting responsibility for the 

flight must make a visual inspection throughout the Class B cargo compartment for 

familiarization, after the cargo door is closed and secured."

NOTE 3: This visual inspection is in no manner intended to relieve the pilot of 

his/her responsibility to ensure safe operation of the airplane, as required by FAR 91.3. 

(c) Compliance with paragraph (b)(1) or (b)(2) of this AD constitutes terminating 

action for the requirements of paragraph (a) of this AD. Compliance with paragraph 

(b)(3) or (b)(4) of this AD constitutes terminating action for the requirements of paragraphs 

(a)(1) and (a)(3) of this AD.

(d) An alternative method of compliance or adjustment of the compliance time 

that provides an acceptable level of safety may be used if approved by the Manager, Seattle 

Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate (for affected 

Boeing series airplanes); or the Manager, Los Angeles Aircraft Certification Office 

(ACO), FAA, Transport Airplane Directorate (for affected McDonnell Douglas series 

airplanes). Operators shall submit their requests through an appropriate FAA Principal 

Maintenance Inspector, who may add comments and then send it to the Manager, of the 

Seattle ACO, or the Manager of the Los Angeles ACO, as appropriate.

NOTE 4: Information concerning the existence of approved alternative methods 

of compliance with this AD, if any, may be obtained from the Seattle ACO or the Los 

Angeles ACO.

NOTE 5: Alternative methods of compliance previously granted for Amendment 

39-6557, AD 89-18-12 R1; or Amendment 39-6986, AD 91-10-02; continue to be 

considered as acceptable alternative methods of compliance with this amendment.

(e) Special flight permits may be issued in accordance with FAR 21.197 and 

21.199 to operate the airplane to a location where the requirements of this AD can be 

accomplished.

(f) This amendment becomes effective on May 2, 1993. 

Issued in Renton, Washington, on April 14, 1993.
14

Original Signed By:

Darrell M. Pederson, Acting Manager

Transport Airplane Directorate 

Aircraft Certification Service
EXECUTIVE SUMMARY

DATE: March 24, 1993

SUBJECT: McDonnell Douglas and Boeing models; Final Rule after NPRM; Docket 

92-NM-67-AD

PROJECT ENGINEER/TECH WRITER: Sue Letcher, ANM-130S; 

Jill DeMarco, ANM-103

BACKGROUND: On April 19, 1991, the FAA issued AD 90-10-02 to require (1) modification 

of all Class B cargo compartments to Class C, or (2) the use of flame penetration-resistant cargo 

containers equipped with smoke detection and fire extinguishing systems, or (3) the use of 

individuals trained to fight cargo fires and certain modifications to Class B cargo compartments 

and associated systems. That action was prompted by an FAA evaluation following the loss of a 

Boeing Model 747-200 "Combi" airplane that developed a major fire in the main deck cargo 

compartment. That AD contained a provision for submission of additional comments from the 

public concerning the firefighting concepts and training guidelines, and for the re-evaluation some 

of the more extensive required modifications. 

UNSAFE CONDITION: Airplanes with Class B main deck cargo compartments do not have 

adequate smoke/fire detection and protection features to prevent the occurrence of an uncontrolled 

cargo fire that could cause systems and structural damage, leading to loss of an airplane.

ACTION: On July 21, 1992, the FAA issued an NPRM proposing to supersede the AD 

90-10-02 to include additional optional actions and to delete other previously required actions. 

The new proposed requirements include: (1) use of an extended halon system; (2) an increase in 

protective breathing/garment quantities; (3) change in illumination criteria; (4) use of 

blankets/containers; and (5) one-minute smoke detection. This deleted requirements include: 

(1) use of trained firefighters, (2) installation of a thermal monitoring systems, and (3) installation 

of extensive liners. 

Most comments received were requests for clarification of certain wording in the rule, and requests 

for consideration of unique airplane configurations (which the FAA will handle through the 

"alternative methods of compliance" provision of the final rule). The only substantive change was 

an extension of the compliance time for the (new) requirements of the rule. The proposed 

compliance time of 30 months was based on initial estimates for designing, producing, and 

installing modifications on the affected airplanes. However, based on the production schedule for 

the new modification kits for these airplanes, a compliance time of 42 months is more realistic 

and warranted. of 42 months.

COST IMPACT: Worldwide fleet: 402; U.S. registered airplanes: 40*

(

*Although 124 U.S.-registered airplanes are certificated to operate with a Class B main deck 

cargo compartment, only 40 operate as Combis.) 

The design alternative and airplane type will have significant impact on the cost of complying with 

this AD. An estimated average cost could range from $2,000,000/airplane for incorporating 

extended halon option, to $200,000/airplane for incorporation of the blanket/container option.

The AD has no additional cost burden on U.S. operators. The only U.S. operators of Combis were 

previously granted alternative methods of compliance with the existing AD.

AFFECTED U.S. OPERATORS: Alaska, MarkAir, Continental, NMB, Federal Express, 
Aloha, Evergreen, Flying Tigers, Reeve Aleutian, U.S. Air Force

COORDINATED WITH: JAA, Transport Canada, ATA, Boeing, McDonnell Douglas

ENFORCEMENT ACTION INVOLVED? Not applicable.

CONTROVERSIAL ISSUES / MEDIA INTEREST: This issue has worldwide impact. It 

has been a "high visibility" topic among world aviation authorities for the past four years. 

 AIR-1 _____________

Date _____________

ADMINISTRATOR'S AIRWORTHINESS DIRECTIVE ALERT

SUBJECT: McDonnell Douglas and Boeing models; Final Rule after NPRM; Docket 92-NM-67-AD

BACKGROUND: In 1987, a South African Airways Boeing Model 747-200 "combi" airplane was lost over the Indian Ocean after a fire 

broke out in its main deck cargo compartment. As a result of this accident, the FAA reviewed its airworthiness standards for all 

U.S.-manufactured combination passenger/cargo ("combi") aircraft, and subsequently proposed changes in airworthiness regulations to 

require a higher level of fire detection and protection in these aircraft. 

In April 1991, the FAA issued AD 91-10-02 to require (1) upgrading of all Class B cargo compartments to Class C (which entails enhanced 

fire/smoke detection and protection features); or (2) the use of flame penetration-resistant cargo containers equipped with smoke 

detection and fire extinguishing systems; or (3) certain modifications to Class B cargo compartments and associated systems and the use 

of individuals trained to fight cargo fires. AD 91-10-02 contained a provision for submission of additional comments from the public 

concerning the firefighting concepts and training guidelines, and for the re-evaluation some of the more extensive required modifications. 

UNSAFE CONDITION: Airplanes with Class B main deck cargo compartments do not have adequate smoke/fire detection and 

protection features to prevent the occurrence of an uncontrolled cargo fire that could cause systems and structural damage, leading to 

loss of an airplane.

ACTION: On July 21, 1992, the FAA issued an NPRM proposing to supersede the AD 90-10-02 to include additional optional actions 

and to delete other previously required actions. The new proposed requirements include: (1) use of an extended halon system; (2) an 

increase in protective breathing/garment quantities; (3) change in illumination criteria; (4) use of blankets/containers; and (5) one-minute 

smoke detection. The deleted requirements include: (1) use of trained firefighters, (2) installation of a thermal monitoring systems, and 

(3) installation of extensive liners. 

Most comments received were requests for clarification of certain wording in the rule, and requests for consideration of unique airplane 

configurations (which the FAA will handle through the "alternative methods of compliance" provision of the final rule). The only 

substantive change was an extension of the compliance time for the (new) requirements of the rule from the proposed 30 months to 42 

months, based on problems involving availability of an ample number of modification kits.

This AD action has been coordinated extensively with all foreign aviation authorities; its intent has worldwide acceptance.

COST IMPACT: Worldwide fleet: 402; U.S. registered airplanes: 40*

(

*Although 124 U.S.-registered airplanes are certificated to operate with a Class B main deck cargo compartment, only 40 operate as 

combis.) 

The AD has no additional cost burden on U.S. operators. The only U.S. operators of combis operate in Alaska, and were previously 

granted alternative methods of compliance with the existing AD; those alternative methods continue to be acceptable for this AD.

AFFECTED U.S. AIRLINES: Alaska, MarkAir, Continental, NMB, Federal Express, Aloha, Evergreen, Flying Tigers, Reeve Aleutian, 

U.S. Air Force

NEWS VALUE/MEDIA INTEREST: 

THIS AD WILL BE PUBLISHED IN THE FEDERAL REGISTER WITHIN 7 WORKING DAYS.

cc: S-1, A-1, ADA-1, AOA-2, AXO-1, AVR-1, APA-1 (2), AGC-210, AGC-1, AFS-300, ANM-1
 U.S. DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

TRANSPORT AIRPLANE DIRECTORATE

AIRCRAFT CERTIFICATION SERVICE, ANM-100

════════════════════════════════════════════════════════════════

═

To: AIR-107 Attn: LINDA WALKER 

Phone: (202) 267-9592

════════════════════════════════════════════════════════════════

═

From: R. Jill DeMarco, Supervisory Technical Publications 

 Writer-Editor, ANM-103 

Phone: Office: (206) 227-2125 / Fax: (206) 227-1100

════════════════════════════════════════════════════════════════

═

Total Pages (excluding this lead sheet): 1 

Date of Transmission: April 6, 1993 

════════════════════════════════════════════════════════════════

═

Remarks / Delivery Instructions: 

Here's a new AOA-1 Alert for the combi AD. I added a few words about the 

Alaskan operators, under "COST IMPACT"

Call me when all is clear. Thanks!

════════════════════════════════════════════════════════════════

This message transmitted by the Federal Aviation Administration,

Aircraft Certification Service, 1601 Lind Avenue S.W.,

Renton, Washington 98055-4056