[Federal Register Volume 75, Number 69 (Monday, April 12, 2010)]
[Proposed Rules]
[Pages 18446-18449]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-8249]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0275; Directorate Identifier 2009-NM-231-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400,
747-400F, 747SR, and 747SP Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-
200F, 747-300, 747-400, 747-400F, 747SR, and 747SP series airplanes.
This proposed AD would require reworking or replacing certain duct
assemblies in the environmental control system (ECS). This proposed AD
results from reports of duct assemblies in the ECS with burned Boeing
Material Specification (BMS) 8-39 polyurethane foam insulation. This
proposed AD also results from a report from the airplane manufacturer
that airplanes were assembled with duct assemblies in the ECS wrapped
with BMS 8-39 polyurethane foam insulation, a material of which the
fire retardant properties deteriorate with age. We are proposing this
AD to prevent a potential electrical arc from igniting the BMS 8-39
polyurethane foam insulation on the duct assemblies of the ECS, which
could propagate a small fire and lead to a larger fire that might
spread throughout the airplane through the ECS.
DATES: We must receive comments on this proposed AD by May 27, 2010.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this proposed AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management, P.
O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail [email protected];
Internet https://www.myboeingfleet.com. You may review copies of the
referenced service information at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue SW., Renton, Washington. For information
on the availability of this material at the FAA, call 425-227-1221.
[[Page 18447]]
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Sue McCormick, Aerospace Engineer,
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone (303) 342-1082; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0275;
Directorate Identifier 2009-NM-231-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
Discussion
We have received reports of duct assemblies in the environmental
control system (ECS) with burned Boeing Material Specification (BMS) 8-
39 polyurethane foam insulation on two Model 767-200 series airplanes.
The airplane manufacturer has also notified us that certain Model 767-
200 and 767-300 series airplanes and certain Model 747 airplanes were
assembled with duct assemblies in the ECS wrapped with BMS 8-39
polyurethane foam insulation. The fire-retardant properties of the BMS
8-39 polyurethane foam insulation deteriorate with age. This, along
with dust, dirt, and other carbon particulate contamination of the
insulation on the ducts, adds an available fuel source for a potential
fire. Once ignited, the foam insulation emits noxious smoke, does not
self-extinguish, and drips droplets of liquefied polyurethane, which
can further propagate a fire. Because the insulation is wrapped around
the duct assemblies, which are located throughout the airplane, if the
insulation is ignited a fire could potentially travel along the ducts
and spread throughout the airplane. This condition, if not corrected,
could result in a potential electrical arc igniting the BMS 8-39
polyurethane foam insulation on the duct assemblies of the ECS, which
could propagate a small fire and lead to a larger fire that may spread
throughout the airplane through the ECS.
Other Relevant Rulemaking
On January 14, 2008, we issued AD 2008-02-16, amendment 39-15346,
applicable to certain Model 767-200 and 767-300 series airplanes. That
AD requires reworking certain duct assemblies in the ECS. That AD
resulted from reports of duct assemblies in the ECS with burned BMS 8-
39 polyurethane foam insulation. That AD also resulted from a report
from the airplane manufacturer that airplanes were assembled with duct
assemblies in the ECS wrapped with BMS 8-39 polyurethane foam
insulation, a material of which the fire retardant properties
deteriorate with age. We issued that AD to prevent a potential
electrical arc from igniting the BMS 8-39 polyurethane foam insulation
on the duct assemblies of the ECS, which could propagate a small fire
and lead to a larger fire that might spread throughout the airplane
through the ECS.
Additionally, on December 14, 2001, we issued AD 2001-26-09,
amendment 39-12573 (66 FR 66734, December 27, 2001), applicable to
certain Model 767-200 series airplanes. That AD requires a one-time
inspection for damage of the water line heater tape where it passes
close to the duct assemblies of the air distribution system for the
flight compartment. That AD also requires eventual replacement of
certain duct assemblies or foam insulation on those duct assemblies
with new assemblies or improved foam insulation. That AD was prompted
by a report of burned BMS 8-39 polyurethane foam insulation on an air
distribution system duct located in the electronics and electrical
compartment. The actions required by that AD are intended to prevent
ignition of foam insulation on the air distribution ducts, which could
result in a fire in the airplane.
We are considering additional rulemaking for Model 737-100, -200, -
200C, and -300 series airplanes, which have been determined to be
subject to the same unsafe condition.
Relevant Service Information
We have reviewed Boeing Service Bulletin 747-21A2421, Revision 2,
dated December 19, 2006. This service bulletin describes procedures for
reworking the affected duct assemblies in approximately 44 locations
within the ECS systems. The affected duct assemblies vary depending on
airplane configuration. These are some examples of affected ECS
systems:
Air conditioning, flight deck
Duct installation, conditioned air
Duct installation, air distribution system
Duct installation, individual air system
Anemostat installation, air distribution system
Humidifier duct installation
Heat exchanger installation, air conditioning system
Recirculation fan installation, flight deck
We have also reviewed Boeing Service Bulletin 747-21A2422, Revision
2, dated November 16, 2006. This service bulletin describes procedures
for reworking or replacing the single duct assembly in the forward
lower cargo bay. The rework includes removing the BMS 8-39 polyurethane
foam insulation and replacing it with BMS 8-300 polyimide foam
insulation that meets flammability criteria of Section 25.856 (``Fire
Protection: Thermal/Acoustic Insulation Materials'') of the Federal
Aviation Regulations (14 CFR 25.856(a)).
These service bulletins also describe procedures for part-marking
reworked duct assemblies with new part numbers.
FAA's Determination and Requirements of This Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
This proposed AD would require accomplishing the actions specified in
the service information described previously, except as discussed under
``Differences Between the Proposed AD and the Service Bulletins.''
Differences Between the Proposed AD and the Service Bulletins
Boeing Service Bulletin 747-21A2421, Revision 2, dated December 19,
2006, recommends reworking the affected duct assemblies ``during the
next heavy maintenance visit, not to
[[Page 18448]]
exceed 30,000 flight-hours'' from the date on that service bulletin.
Boeing Service Bulletin 747-21A2422, Revision 2, dated November 16,
2006, does not recommend any compliance time for reworking or replacing
the affected duct assemblies. This proposed AD would require operators
to rework or replace the affected duct assemblies within 72 months
after the effective date of the AD. In developing the compliance time
for this action, we considered the degree of urgency associated with
addressing the subject unsafe condition. We also considered the
availability of required parts and the practical aspect of reworking or
replacing the affected duct assemblies within an interval that
parallels normal scheduled maintenance for most affected operators. We
have determined that the average utilization of the Model 747 fleet is
approximately 5,000 flight hours each year. Therefore, we have
determined that 72 months is equivalent to the recommended compliance
time of 30,000 flight hours and it represents an appropriate interval
in which an ample number of required parts will be available to modify
the affected fleet without adversely affecting the safety of these
airplanes. This difference has been coordinated with Boeing.
Costs of Compliance
There are about 558 airplanes of the affected design in the
worldwide fleet. The average labor rate is $85 per work-hour. The
following table provides the estimated costs for U.S. operators to
comply with this proposed AD.
Estimated Costs
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Parts cost, per Number of U.S.-
Action Work hours airplane Cost per airplane registered airplanes Fleet cost
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Duct assembly rework, specified in 8 per duct (average of $12,305 (average)..... $100,705 (average)... 185.................. $18,630,425.
Boeing Service Bulletin 130 ducts per
747[dash]21A2421. airplane).
Duct assembly rework or 1 per duct (1 duct per The manufacturer $85.................. Up to 168............ Up to $14,280.
replacement, specified in Boeing airplane). states that it will
Service Bulletin 747[dash]21A2422. supply required parts
to the operators at
no cost..
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Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. ``Subtitle VII: Aviation
Programs,'' describes in more detail the scope of the Agency's
authority.
We are issuing this rulemaking under the authority described in
``Subtitle VII, Part A, Subpart III, Section 44701: General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect 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.
For the reasons discussed above, I certify this proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866,
2. Is not a ``significant rule'' under the 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new AD:
The Boeing Company: Docket No. FAA-2010-0275; Directorate Identifier
2009-NM-231-AD.
Comments Due Date
(a) We must receive comments by May 27, 2010.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the airplanes specified in paragraphs
(c)(1) and (c)(2) of this AD, certificated in any category.
(1) The Boeing Company Model 747-100, 747-100B, 747-100B SUD,
747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 747SP
series airplanes identified in Boeing Service Bulletin 747-21A2421,
Revision 2, dated December 19, 2006.
(2) The Boeing Company Model 747-100, 747-100B, 747-200B, 747-
200C, 747-200F, 747-300, 747-400F, 747SR, and 747SP series airplanes
identified in Boeing Service Bulletin 747-21A2422, Revision 2, dated
November 16, 2006.
Subject
(d) Air Transport Association (ATA) of America Code 21: Air
conditioning.
Unsafe Condition
(e) This AD results from reports of duct assemblies in the
environmental control system (ECS) with burned Boeing Material
Specification (BMS) 8-39 polyurethane foam insulation. This AD also
results from a report from the airplane manufacturer that airplanes
were assembled with duct assemblies in the ECS wrapped with BMS 8-39
polyurethane foam insulation, a material of which the fire retardant
properties deteriorate with age. We are issuing this AD to prevent a
potential electrical arc from igniting the BMS 8-39 polyurethane
foam insulation on the duct assemblies of the ECS, which could
[[Page 18449]]
propagate a small fire and lead to a larger fire that could spread
throughout the airplane through the ECS.
Compliance
(f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
ECS Duct Assembly Rework or Replacement
(g) Within 72 months after the effective date of this AD, rework
or replace the applicable duct assemblies in the ECS specified in
and in accordance with the Accomplishment Instructions and
Appendices A through F of Boeing Service Bulletin 747-21A2421,
Revision 2, dated December 19, 2006 (for Model 747-100, 747-100B,
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR,
and 747SP series airplanes); and the Accomplishment Instructions and
Appendices A through C of Boeing Service Bulletin 747-21A2422,
Revision 2, dated November 16, 2006 (for Model 747-100, 747-100B,
747-200B, 747-200C, 747-200F, 747-300, 747-400F, 747SR, and 747SP
series airplanes).
Parts Installation
(h) As of the effective date of this AD, no person may install
an ECS duct assembly with BMS 8-39 polyurethane foam insulation on
any airplane.
Alternative Methods of Compliance (AMOCs)
(i)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. Send information to
ATTN: Sue McCormick, Aerospace Engineer, Cabin Safety and
Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington
98057-3356; telephone (303) 342-1082; fax (425) 917-6590. Or, e-mail
information to [email protected].
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically reference this AD.
Issued in Renton, Washington, on April 1, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-8249 Filed 4-9-10; 8:45 am]
BILLING CODE 4910-13-P