Airworthiness Directives; Boeing Model 747 Series Airplanes

[Federal Register Volume 65, Number 233 (Monday, December 4, 2000)]
[Rules and Regulations]
[Pages 75582-75585]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-30399]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-377-AD; Amendment 39-12014; AD 2000-24-07]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 747 series airplanes, that requires 
inspections to detect cracking of the frame web, doubler, and inner 
chord of the forward edge frame of main entry door number 1, and 
various follow-on actions. This amendment is prompted by reports of 
cracking in the frame web, doubler, inner chord, and strap of the 
forward edge frame of main entry door number 1. The actions specified 
by this AD are intended to prevent cracks in the frame web and doubler 
of the forward edge frame of main entry door number 1, which could 
result in inability of the edge frame to react door stop loads, and 
consequent rapid depressurization of the airplane.

DATES: Effective January 8, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 8, 2001.

ADDRESSES: 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 Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 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: Rick Kawaguchi, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1153; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 747 series 
airplanes was published in the Federal Register on

[[Page 75583]]

June 15, 2000 (65 FR 37497). That action proposed to require 
inspections to detect cracking of the frame web, doubler, and inner 
chord of the forward edge frame of main entry door number 1, and 
various follow-on actions.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    Three commenters support the proposed rule.

Request to Reference New Service Information

    One commenter requests that the FAA revise paragraphs (a), (b), and 
(c) of the proposed rule to reference Boeing Alert Service Bulletin 
747-53A2417, Revision 2, dated August 10, 2000, as an acceptable means 
of compliance for the actions required by those paragraphs. (Certain 
paragraphs of the proposed rule reference Boeing Service Bulletin 747-
53A2417, Revision 1, dated July 23, 1998, as the appropriate source of 
service information for accomplishment of the actions required by those 
paragraphs.)
    Because paragraph (a) of the proposed rule does not reference a 
service bulletin but only specifies compliance times, the FAA infers 
that the commenter is requesting that the FAA revise paragraphs (b) and 
(c), as well as paragraphs (d) and (e), of the proposed rule. The FAA 
concurs with the commenter's request. Since the issuance of the 
proposed rule, the FAA has reviewed and approved Boeing Alert Service 
Bulletin 747-53A2417, Revision 2. The procedures in that service 
bulletin are substantially similar to those in Boeing Service Bulletin 
747-53A2417, Revision 1. Thus, paragraphs (b), (d), and (e) of this 
final rule have been revised accordingly to reference Revision 2 of the 
service bulletin, in addition to Revision 1, as an acceptable source of 
service information.
    Also, Revision 2 of the service bulletin expands the area of 
inspection specified in Revision 1 of the service bulletin, to include 
detailed visual inspections of the aft side of the frame web (referred 
to as ``Area 3'' in the service bulletin), an area which is specified 
in paragraph (c) of the proposed rule and this final rule. Accordingly, 
paragraph (c) of this AD has been revised to note that Boeing Alert 
Service Bulletin 747-53A2417, Revision 2, dated August 10, 2000, may be 
used to accomplish the inspections specified in that paragraph. Also, 
``Note 5'' of the proposed rule has been amended to clarify that the 
inspections in paragraph (c) of this AD are described in Revision 2 of 
the service bulletin.

Difference Between Revision 2 of the Service Bulletin and This AD

    Operators should note that, in addition to the detailed visual 
inspections of Area 3, the aft side of the frame web, that are 
specified in this AD, Revision 2 of the service bulletin also specifies 
detailed visual inspections of an ``Area 2,'' which comprises the 
forward and aft sides of the frame web and chord. The FAA has 
determined that, because inspections in this area were not specified in 
the proposed rule, to require inspections of this area would expand the 
scope of this AD, necessitating additional notice to the public and 
reopening of the comment period. Due to the criticality of the unsafe 
condition addressed in this AD, the FAA finds that to delay issuance of 
this final rule in this way would be inappropriate. Therefore, this AD 
does not require inspections of ``Area 2,'' as defined in the service 
bulletin. However, the FAA may consider further rulemaking to require 
inspections in this area.

Requests to Correct Typographical Error, Remove Doorstop Locations

    One commenter, who otherwise supports the proposed rule, requests 
that the FAA revise paragraph (c) of the proposed rule to correct a 
typographical error in a reference to a doorstop location. In the 
Federal Register version of the AD, the sentence that is the subject of 
the commenter's request reads, ``Perform a detailed visual inspection 
to detect cracking of the aft side of the forward edge door frame web 
of main entry door number 1 in the exposed area from doorstop #2 
[approximately water line (WL) 218] to doorstop #2 (approximately WL 
245) at body station 434.'' Another commenter suggests that the 
references to doorstop locations be removed entirely from the 
paragraph.
    The FAA acknowledges the typographical error pointed out by the 
first commenter. The FAA has determined that the WL references in the 
subject sentence of the proposed rule are correct, and the references 
to the doorstop locations are not necessary to adequately define the 
area that needs to be inspected. Therefore, the FAA concurs with the 
second commenter's suggestion to remove the references to doorstop 
locations. The affected sentence of paragraph (c) of this final rule 
has been revised to read, ``Perform a detailed visual inspection to 
detect cracking of the aft side of the forward edge door frame web of 
main entry door number 1 in the exposed area from approximately [WL] 
218 to approximately WL 245 at body station 434.''

Conclusion

    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 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 685 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 211 
airplanes of U.S. registry will be affected by this AD.
    For Group 1 airplanes (approximately 191 U.S.-registered 
airplanes), it will take approximately 3 work hours per airplane to 
accomplish the required inspections, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact of these 
inspections on U.S. operators of Group 1 airplanes is estimated to be 
$34,380, or $180 per airplane, per inspection cycle.
    For Group 2 airplanes (approximately 20 U.S.-registered airplanes), 
it will take approximately 2 work hours per airplane to accomplish the 
required inspections, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of these inspections on U.S. 
operators of Group 2 airplanes is estimated to be $2,400, or $120 per 
airplane, per inspection cycle.
    For Group 1 airplanes (approximately 191 U.S.-registered 
airplanes), it will take approximately 128 work hours per airplane to 
accomplish the required repair, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of this repair on 
U.S. operators of Group 1 airplanes is estimated to be $1,466,880, or 
$7,680 per airplane.
    For Group 2 airplanes (approximately 20 U.S.-registered airplanes), 
it will take approximately 64 work hours per airplane to accomplish the 
required repair, at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of this repair on U.S. operators of 
Group 2 airplanes is estimated to be $76,800, or $3,840 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no

[[Page 75584]]

operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.
    Should an operator elect to accomplish the reinforcement of the 
door frame on a Group 1 airplane, it would take approximately 9 work 
hours per airplane to accomplish the reinforcement, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the reinforcement on a Group 1 airplane is estimated to be $540 per 
airplane.
    Should an operator elect to accomplish the reinforcement of the 
door frame on a Group 2 airplane, it would take approximately 5 work 
hours per airplane to accomplish the reinforcement, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the reinforcement on a Group 2 airplane is estimated to be $300 per 
airplane.

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:

2000-24-07  Boeing: Amendment 39-12014. Docket 99-NM-377-AD.

    Applicability: Model 747 series airplanes, line numbers 1 
through 685 inclusive, certificated in any category.

    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 (g) 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 prevent fatigue cracking of the frame web and doubler of the 
forward edge frame of main entry door number 1, which could result 
in inability of the edge frame to react door stop loads, and 
consequent rapid depressurization of the airplane, accomplish the 
following:

Initial Inspection: Compliance Time

    (a) At the time specified in paragraph (a)(1), (a)(2), (a)(3), 
or (a)(4) of this AD; as applicable; accomplish the requirements of 
paragraphs (b) and (c) of this AD.
    (1) For airplanes that have accumulated fewer than 13,000 total 
flight cycles as of the effective date of this AD: Inspect prior to 
the accumulation of 13,000 total flight cycles, or within 1,500 
flight cycles after the effective date of this AD, whichever occurs 
later.
    (2) For airplanes that have accumulated 13,000 or more total 
flight cycles but fewer than 20,000 total flight cycles as of the 
effective date of this AD: Inspect prior to the accumulation of 
21,000 total flight cycles, or within 1,500 flight cycles after the 
effective date of this AD, whichever occurs first.
    (3) For airplanes that have accumulated 20,000 or more total 
flight cycles but fewer than 25,000 total flight cycles as of the 
effective date of this AD: Inspect prior to the accumulation of 
25,500 total flight cycles, or within 1,000 flight cycles after the 
effective date of this AD, whichever occurs first.
    (4) For airplanes that have accumulated 25,000 or more total 
flight cycles as of the effective date of this AD: Inspect within 
500 flight cycles after the effective date of this AD.

Initial Detailed Visual and High Frequency Eddy Current Inspections

    (b) Perform a detailed visual inspection and a high frequency 
eddy current inspection of the frame web, doubler, and inner chord 
of the forward edge door frame to detect cracking of main entry door 
number 1, in accordance with Boeing Service Bulletin 747-53A2417, 
Revision 1, dated July 23, 1998; or Boeing Alert Service Bulletin 
747-53A2417, Revision 2, dated August 10, 2000. For Group 1 
airplanes (as identified in the service bulletin), accomplish the 
inspections on the left and right sides of the airplane. For Group 2 
airplanes (as identified in the service bulletin), accomplish the 
inspections on the left side of the airplane only.

    Note 2: For the purposes of this AD, it is not necessary to 
count flight cycles accumulated at 2.0 pounds per square inch or 
less differential pressure.


    Note 3: Inspections, reinforcements, and repairs accomplished 
prior to the effective date of this AD in accordance with Boeing 
Alert Service Bulletin 747-53A2417, dated June 25, 1998, are 
considered acceptable for compliance with paragraph (b) of this AD.


    Note 4: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

Repetitive Detailed Visual Inspections (No Terminating Action)

    (c) Remove the cover assembly for the body torque tube located 
between the door hinge attachments. Perform a detailed visual 
inspection to detect cracking of the aft side of the forward edge 
door frame web of main entry door number 1 in the exposed area from 
approximately water line (WL) 218 to approximately WL 245 at body 
station 434. Pay particular attention to the row of fasteners that 
attach the frame web to the frame outer chord. After completing 
inspections, replace the cover assembly. Repeat the inspection 
thereafter at intervals not to exceed 3,000 flight cycles. Boeing 
Alert Service Bulletin 747-53A2417, Revision 2, dated August 10, 
2000, may be used to accomplish these inspections.

    Note 5: The inspections required by paragraph (c) of this AD are 
not described in Boeing Service Bulletin 747-53A2417, Revision 1, 
dated July 23, 1998. However, these inspections are described in 
Boeing Alert Service Bulletin 747-53A2417, Revision 2, dated August 
10, 2000.



[[Page 75585]]


    Note 6: There is no terminating action currently available for 
the inspections required by paragraph (c) of this AD.

Repetitive Inspections/Reinforcement/Repair (No Cracks Detected)

    (d) If no crack is detected during the inspection required by 
paragraph (b) of this AD, prior to further flight, oversize fastener 
holes in accordance with Boeing Service Bulletin 747-53A2417, 
Revision 1, dated July 23, 1998; or Boeing Alert Service Bulletin 
747-53A2417, Revision 2, dated August 10, 2000; and accomplish the 
requirements of paragraph (d)(1), (d)(2), or (d)(3) of this AD.
    (1) Repeat the inspections specified in paragraph (b) of this AD 
one time within 3,000 flight cycles. Within 3,000 flight cycles 
after accomplishment of the repeat inspection, accomplish paragraph 
(d)(2) or (d)(3) of this AD.
    (2) Reinforce the door frame, in accordance with Figure 5 of the 
service bulletin. Thereafter, at intervals not to exceed 3,000 
flight cycles, perform a detailed visual inspection to detect cracks 
of the forward and aft side of the frame, in accordance with Figure 
6 of the service bulletin. Within 10,000 flight cycles after the 
reinforcement, accomplish the requirements of paragraph (d)(3) of 
this AD.
    (3) Accomplish the web replacement repair (``Terminating 
Action'') in accordance with the service bulletin. Such repair 
constitutes terminating action for the repetitive inspection 
requirements of paragraphs (d)(1) and (d)(2) of this AD.

Repair (Cracks Detected)

    (e) If any crack is detected during any inspection required by 
paragraph (b), (d)(1), or (d)(2) of this AD, prior to further 
flight, accomplish the repair (``Terminating Action'') in accordance 
with Boeing Service Bulletin 747-53A2417, Revision 1, dated July 23, 
1998; or Boeing Alert Service Bulletin 747-53A2417, Revision 2, 
dated August 10, 2000. Such repair constitutes terminating action 
for the repetitive inspection requirements of paragraphs (d)(1) and 
(d)(2) of this AD.

Repair

    (f) If any cracking is detected during the inspection required 
by paragraph (c) of this AD, prior to further flight, repair in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or in accordance with data meeting 
the type certification basis of the airplane approved by a Boeing 
Company Designated Engineering Representative (DER) who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the approval letter must specifically 
reference this AD.

Alternative Methods of Compliance

    (g) 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 ACO. 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 7: 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

    (h) 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

    (i) Except as provided in paragraph (f) of this AD, the actions 
shall be done in accordance with Boeing Service Bulletin 747-
53A2417, Revision 1, dated July 23, 1998; or Boeing Alert Service 
Bulletin 747-53A2417, Revision 2, dated August 10, 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

    (j) This amendment becomes effective on January 8, 2001.

    Issued in Renton, Washington, on November 22, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-30399 Filed 12-1-00; 8:45 am]
BILLING CODE 4910-13-P

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