[Federal Register Volume 65, Number 101 (Wednesday, May 24, 2000)]
[Rules and Regulations]
[Pages 33444-33446]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-12671]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-75-AD; Amendment 39-11736; AD 2000-10-12]
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 adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 747-

[[Page 33445]]

400 series airplanes. This action requires repetitive inspections to 
detect damage or deflection of the crew rest heat exchanger, and 
follow-on actions, if necessary. This amendment is prompted by reports 
of cracking and buckling of the front edge of the crew rest heat 
exchanger on several airplanes. The actions specified in this 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.

DATES: Effective June 8, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 8, 2000.
    Comments for inclusion in the Rules Docket must be received on or 
before July 24, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-75-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    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, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2983; fax (425) 
227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that 
cracking and buckling of the forward edge of the crew rest heat 
exchanger has been found on several airplanes. Investigation revealed 
that certain heat exchangers were manufactured with material that is 
too thin. On one airplane, the heat exchanger buckled and bulged enough 
to make contact with the rudder and elevator cables located below the 
heat exchanger. Such contact between the heat exchanger and the rudder 
and elevator control cables could eventually dislodge pieces of the 
heat exchanger or adjacent fasteners. Dislodged pieces or fasteners 
could cause a jam of the rudder or elevator control cables. This 
condition, if not corrected, could result in reduced controllability of 
the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
747-21A2412, dated January 20, 2000. The alert service bulletin 
describes procedures for repetitive general visual inspections to 
detect damage or deflection of the crew rest heat exchanger, and 
follow-on actions, if necessary. If damage or deflection is found, 
follow-on actions include replacement of the affected heat exchanger 
with a new heat exchanger, and measurement of the thickness of material 
of the discrepant heat exchanger. If the thickness of the material is 
within certain limits, the alert service bulletin specifies that the 
discrepant heat exchanger should be returned to Boeing.

Explanation of Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to detect and correct cracking or buckling of the crew 
rest heat exchanger, which could result jamming of the rudder or 
elevator control cables, and consequent reduced controllability of the 
airplane. This AD requires accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

Difference Between This AD and the Alert Service Bulletin

    Operators should note that there is a typographical error in the 
Accomplishment Instructions on page 10 of the alert service bulletin. 
Item G. under the heading ``Inspection and Replacement of the Heat 
Exchanger (All Airplanes)'' reads, ``If the material thickness is 
between 0.028--0.034 inches[,] send the damaged heat exchanger and your 
inspection results to Boeing.'' The number ``0.034'' should read 
``0.038.'' ``NOTE 3'' has been included in this AD for clarification of 
this point.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Cost Impact

    None of the 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 require approximately 1 work hour to 
accomplish the required inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of this AD would be 
$60 per airplane, per inspection cycle.

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.
    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

[[Page 33446]]

submit a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket Number 2000-NM-75-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.

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 adding the following new 
airworthiness directive:

2000-10-12 Boeing: Amendment 39-11736. Docket 2000-NM-75-AD.

    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 (c) 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.
    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, accomplish the following:

Repetitive Inspections

    (a) Within 1,200 flight hours or 90 days after the effective 
date of this AD, 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. Repeat the inspection thereafter at 
intervals not to exceed 2,500 flight hours.

    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, and measure the thickness of the material of the 
discrepant heat exchanger, in accordance with Boeing Alert Service 
Bulletin 747-21A2412, dated January 20, 2000. If the material is 
greater than or equal to 0.028 inches thick but less than or equal 
to 0.038 inches thick ( 0.028 but  0.038 
inches thick), send the damaged heat exchanger and inspection 
results to the Manager of Service Bulletin Engineering, Boeing 
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124.

    Note 3: There is a typographical error in the Accomplishment 
Instructions on page 10 of the alert service bulletin. Item G. under 
the heading ``Inspection and Replacement of the Heat Exchanger (All 
Airplanes)'' reads, ``If the material thickness is between 0.028--
0.034 inches[,] send the damaged heat exchanger and your inspection 
results to Boeing.'' The number ``0.034'' should read ``0.038.''

Alternative Methods of Compliance

    (c) 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. 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.

    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

    (d) 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

    (e) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-21A2412, dated January 20, 2000. This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. 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 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (f) This amendment becomes effective on June 8, 2000.

    Issued in Renton, Washington, on May 15, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-12671 Filed 5-22-00; 8:45 am]
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