AD 2001-18-04

[Federal Register Volume 66, Number 173 (Thursday, September 6, 2001)]
[Rules and Regulations]
[Pages 46512-46515]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-22087]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-119-AD; Amendment 39-12430; AD 2001-18-04]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747-400 series airplanes, that 
currently requires repetitive inspections to detect damage or 
deflection of the crew rest heat exchanger, and follow-on actions, if 
necessary. This amendment adds a new requirement for a one-time 
inspection to determine the part number and shop code of the shell of 
the crew rest heat exchanger; and follow-on actions, if necessary; 
which terminate the currently required repetitive inspections. This 
action is necessary to prevent cracking and buckling of the front edge 
of the crew rest heat exchanger, which could result in a jam of the 
rudder or elevator control cables, and consequent reduced 
controllability of the airplane. This action is intended to address the 
identified unsafe condition.

DATES: Effective September 21, 2001.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-21A2412, Revision 2, dated November 30, 2000, as listed in the 
regulations, is approved by the Director of the Federal Register as of 
September 21, 2001.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-21A2412, dated January 20, 2000, as listed in the regulations, was 
approved previously by the Director of the Federal Register as of June 
8, 2000 (65 FR 33444, May 24, 2000).
    Comments for inclusion in the Rules Docket must be received on or 
before November 5, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-119-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may also be sent via the Internet using the 
following address: <a href="/cdn-cgi/l/email-protection#fcc5d19d9291d1959d8e9f939191999288bc9a9d9dd29b938a"><span class="__cf_email__" data-cfemail="b58c98d4dbd898dcd4c7d6dad8d8d0dbc1f5d3d4d49bd2dac3">[email&#160;protected]</span></a>. Comments sent via the 
Internet must contain ``Docket No. 2001-NM-119-AD'' in the subject line 
and need not be submitted in triplicate.
    The service information referenced in this AD may be obtained from 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Barbara Mudrovich, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2983; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: On May 15, 2000, the FAA issued AD 2000-10-
12, amendment 39-11736 (65 FR 33444, May 24, 2000), applicable to 
certain Boeing Model 747-400 series airplanes, to require repetitive 
inspections to detect damage or deflection of the crew rest heat 
exchanger, and follow-on actions, if necessary. That action was 
prompted by reports of cracking and buckling of the front edge of the 
crew rest heat exchanger on several airplanes. The requirements of that 
AD are intended to detect and correct damage or deflection of the crew 
rest heat exchanger, which could result in jamming of the rudder or 
elevator control cables, and consequent reduced controllability of the 
airplane.
    In the preamble to AD 2000-10-12, the FAA indicated that the 
actions required by that AD were considered ``interim action'' and that 
further rulemaking action was being considered. We now have determined 
that further rulemaking action is indeed necessary, and this AD follows 
from that determination.

Actions Since Issuance of Existing AD

    Since the issuance of AD 2000-10-12, we have reviewed and approved 
Boeing Alert Service Bulletin 747-21A2412, Revision 2, dated November 
30, 2000. (AD 2000-10-12 referred to the original issue of Boeing Alert 
Service Bulletin 747-21A2412, dated January 20, 2000, as the 
appropriate source of service information for the required actions.) 
Among other changes, Revision 2 of the service bulletin adds a new one-
time inspection to determine the part number and shop code of the shell 
assembly of the crew rest heat exchanger. The service bulletin also 
describes procedures for certain follow-on actions if the shell has a 
certain part number and shop code, or if the shop code cannot be 
determined. The follow-on actions involve removing the shell assembly 
of the heat exchanger; measuring the thickness of the wall of the shell 
adjacent to the forward flange; remarking the part, if necessary; and 
replacing the shell assembly of the crew rest heat exchanger with a new 
shell assembly, if necessary. Accomplishment of the new inspection and 
applicable follow-on actions eliminates the need for the currently 
required repetitive inspections for deflection or damage of the crew 
rest heat exchanger. Accomplishment of the actions specified in 
Revision 2 of the service bulletin is intended to adequately address 
the identified unsafe condition.
    Additionally, paragraph (b) of AD 2000-10-12 contains a requirement 
to measure the thickness of the material of

[[Page 46513]]

discrepant heat exchanger and send certain discrepant heat exchangers 
and inspection results to the airplane manufacturer. Because the 
airplane manufacturer has issued the new service bulletin discussed 
above, which contains a terminating action for the repetitive 
inspections required previously, we find that it is no longer necessary 
to require the measurement and return of discrepant heat exchangers. 
Paragraph (b) has been revised accordingly, and Note 3 of the existing 
AD, which contains information related to the return of damaged heat 
exchangers, has not been included in this AD.

Explanation of Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, this AD 
supersedes AD 2000-10-12 to continue to require repetitive inspections 
to detect damage or deflection of the crew rest heat exchanger, and 
follow-on actions, if necessary. This AD adds a new requirement for a 
one-time inspection to determine the part number and shop code of the 
shell of the crew rest heat exchanger, and follow-on actions, if 
necessary, which terminate the currently required repetitive 
inspections. The actions are required to be accomplished in accordance 
with the service bulletins described previously, except as discussed 
below.

Differences Between Service Bulletin and This AD

    This AD differs from the service bulletin in that the service 
bulletin specifies that the new inspection to determine the part number 
and shop code of the shell of the crew rest heat exchanger be 
accomplished at ``the next heavy maintenance visit.'' We find that such 
a compliance time will not necessarily ensure that the inspection will 
be done in a timely manner. In developing an appropriate compliance 
time for the new inspection required by this AD, we considered not only 
the manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the new 
inspection (less than one hour). In light of all of these factors, we 
find an 18-month compliance time for completing the required inspection 
to be warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety. We find that this compliance time will also be 
sufficient to allow the inspections to be conducted during a regularly 
scheduled maintenance visit for the majority of the affected fleet.

Cost Impact

    None of the Model 747-400 series airplanes affected by this action 
are on the U.S. Register. All airplanes included in the applicability 
of this rule currently are operated by non-U.S. operators under foreign 
registry; therefore, they are not directly affected by this AD action. 
However, the FAA considers that this rule is necessary to ensure that 
the unsafe condition is addressed in the event that any of these 
subject airplanes are imported and placed on the U.S. Register in the 
future.
    Should an affected airplane be imported and placed on the U.S. 
Register in the future, it would take approximately 1 work hour to 
accomplish the inspection currently required by AD 2000-10-12, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of this inspection would be $60 per airplane, per 
inspection cycle.
    Should an affected airplane be imported and placed on the U.S. 
Register in the future, it would take approximately 1 work hour to 
accomplish the new inspection required by this AD, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the new required inspection would be $60 per airplane.

Determination of Rule's Effective Date

    Since this AD action does not affect any airplane that is currently 
on the U.S. register, it has no adverse economic impact and imposes no 
additional burden on any person. Therefore, prior notice and public 
procedures hereon are unnecessary and the amendment may be made 
effective in less than 30 days after publication in the Federal 
Register.

Comments Invited

    Although this action is in the form of a final rule and was not 
preceded by notice and opportunity for public comment, comments are 
invited on this rule. Interested persons are invited to comment on this 
rule by submitting such written data, views, or arguments as they may 
desire. Communications shall identify the Rules Docket number and be 
submitted in triplicate to the address specified under the caption 
ADDRESSES. All communications received on or before the closing date 
for comments will be considered, and this rule may be amended in light 
of the comments received. Factual information that supports the 
commenter's ideas and suggestions is extremely helpful in evaluating 
the effectiveness of the AD action and determining whether additional 
rulemaking action would be needed.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the AD is 
being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-119-AD.'' The postcard will be date-stamped 
and returned to the commenter.

Regulatory Impact

    The regulations adopted herein will 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(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.

[[Page 46514]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by removing amendment 39-11736 (65 FR 
33444, May 24, 2000), and by adding a new airworthiness directive (AD) 
amendment 39-12430, to read as follows:

2001-18-04  Boeing: Amendment 39-12430. Docket 2001-NM-119-AD. 
Supersedes AD 2000-10-12, Amendment 39-11736.

    Applicability: Model 747-400 series airplanes, line numbers 1 
through 1205 inclusive, certificated in any category, and equipped 
with dual crown skin heat exchangers.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (f)(1) 
of this AD. The request should include an assessment of the effect 
of the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.

Restatement of Requirements of AD 2000-10-12

Repetitive Inspections

    (a) Within 1,200 flight hours or 90 days after June 8, 2000 (the 
effective date of AD 2000-10-12, amendment 39-11736), whichever 
occurs first, perform a general visual inspection of the crew rest 
heat exchanger to detect deflection or damage, in accordance with 
Boeing Alert Service Bulletin 747-21A2412, dated January 20, 2000, 
or Revision 2, dated November 30, 2000. Repeat the inspection 
thereafter at intervals not to exceed 2,500 flight hours, until 
paragraph (d) of this AD is accomplished.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light, and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Corrective Action

    (b) If any damage or deflection is detected during any 
inspection required by paragraph (a) of this AD, prior to further 
flight, replace the discrepant heat exchanger with a new heat 
exchanger, in accordance with Boeing Alert Service Bulletin 747-
21A2412, dated January 20, 2000, or Revision 2, dated November 30, 
2000.

New Requirements of This AD

    Note 3: Inspections and replacements accomplished prior to the 
effective date of this AD in accordance with Boeing Alert Service 
Bulletin 747-21A2412, Revision 1, dated August 31, 2000; are 
considered acceptable for compliance with paragraphs (a) and (b) of 
this AD.

Determination of the Part Number of the Heat Exchanger Shell

    (c) Within 18 months after the effective date of this AD, do an 
inspection to determine the part number of the shell assembly of the 
crew rest heat exchanger, according to Boeing Alert Service Bulletin 
747-21A2412, Revision 2, dated November 30, 2000.
    (1) If the part number of the shell is NOT listed in the 
``Existing Part Number'' column of the ``Existing Parts 
Accountability'' table under Section 2.E. of the service bulletin: 
No further action is required by this AD. This terminates the 
repetitive inspections required by paragraph (a) of this AD.
    (2) If the part number is listed in the ``Existing Part Number'' 
column of the ``Existing Parts Accountability'' table under Section 
2.E. of the service bulletin, but the shop code is NOT A3210: No 
further action is required by this AD. This terminates the 
repetitive inspections required by paragraph (a) of this AD.
    (3) If the part number is listed in the ``Existing Part Number'' 
column of the ``Existing Parts Accountability'' table under Section 
2.E. of the service bulletin, and the shop code is A3210 or cannot 
be determined, do paragraph (d) of this AD.

Measurement of Wall of Shell Assembly and Corrective Action

    (d) For airplanes on which the shell assembly of the crew rest 
heat exchanger has the part number listed in the ``Existing Part 
Number'' column of the ``Existing Parts Accountability'' table under 
Section 2.E. of Boeing Alert Service Bulletin 747-21A2412, Revision 
2, dated November 30, 2000, and the shop code is A3210 or cannot be 
determined: Before further flight, remove the shell assembly of the 
heat exchanger and measure the thickness of the wall of the shell 
adjacent to the forward flange, according to the service bulletin.
    (1) If the thickness of the wall of the shell is equal to or 
greater than 0.028 inch: Re-mark the part if the part marking was 
unreadable, and reinstall the shell assembly, according to the 
service bulletin. No further action is required by this AD. This 
terminates the repetitive inspections required by paragraph (a) of 
this AD.
    (2) If the thickness is less than 0.028 inch: Replace the shell 
assembly with a new shell assembly, according to the service 
bulletin. This terminates the repetitive inspections required by 
paragraph (a) of this AD.

Spares

    (e) As of the effective date of this AD, no one may install a 
crew rest heat exchanger on any airplane unless paragraphs (c) and 
(d) of this AD, as applicable, have been done on that heat 
exchanger.

Alternative Methods of Compliance

    (f)(1) 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. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2000-10-12, amendment 39-11736, are approved as 
alternative methods of compliance with this AD.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (g) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (h) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-21A2412, dated January 20, 2000; or Boeing 
Alert Service Bulletin 747-21A2412, Revision 2, dated November 30, 
2000; as applicable.
    (1) The incorporation by reference of Boeing Alert Service 
Bulletin 747-21A2412, Revision 2, dated November 30, 2000, is 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51.
    (2) The incorporation by reference of Boeing Alert Service 
Bulletin 747-21A2412, dated January 20, 2000, was approved 
previously by the Director of the Federal Register as of June 8, 
2000 (65 FR 33444, May 24, 2000).
    (3) Copies may be obtained from Boeing Commercial Airplane 
Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal

[[Page 46515]]

Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (i) This amendment becomes effective on September 21, 2001.

    Issued in Renton, Washington, on August 27, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-22087 Filed 9-5-01; 8:45 am]
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