[Federal Register Volume 65, Number 155 (Thursday, August 10, 2000)]
[Proposed Rules]
[Pages 48943-48945]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-20246]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-18-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Boeing Model 727 series 
airplanes. This proposal would require repetitive inspections of the 
bearing support fitting of the forward trunnion on the main landing 
gear (MLG) to detect corrosion and cracking; follow-on actions, if 
necessary; and rework of the support fitting. This action is necessary 
to prevent failure of the support fitting, which could result in 
collapse of the MLG during normal operations; consequent damage to the 
airplane structure; and injury to flight crew, passengers, or ground 
personnel. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by September 25, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-18-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-18-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule 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.

FOR FURTHER INFORMATION CONTACT: Walter Sippel, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, 
Washington; telephone (425) 227-2028 or (425) 227-2774; fax (425) 227-
1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Submit comments using the following format:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-18-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2000-NM-18-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

[[Page 48944]]

Discussion

    The FAA has received reports indicating collapse of the main 
landing gear (MLG) during normal operations of certain Boeing Model 727 
series airplanes. The affected airplanes had accumulated between 17,000 
and 53,000 total flight cycles. Analysis of the MLG revealed that the 
collapse was caused by fatigue cracking and subsequent breakage of the 
bearing support fitting of the forward trunnion. The alloy steel 
trunnion fitting currently installed on these airplanes is susceptible 
to corrosion and cracking. Such conditions, if not corrected, could 
result in failure of the support fitting; collapse of the MLG; 
consequent damage to the airplane structure; and injury to flight crew, 
passengers, or ground personnel.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
727-57A0179, Revision 4, dated July 13, 2000, which describes 
procedures for ultrasonic, visual, and magnetic particle inspections to 
detect corrosion and cracking of the bearing support fitting of the 
forward trunnion on the MLG, and rework of the fitting if cracking is 
detected. The alert service bulletin also describes procedures for 
eventual rework of the fitting if no cracking is detected. 
Additionally, the alert service bulletin references Boeing Standard 
Practices Overhaul Manual, Chapter 20-30-03, as the appropriate source 
for accomplishment of the cleaning and application of corrosion 
inhibiting compound to the fitting if no cracking is detected. 
Accomplishment of the actions specified in the alert service bulletin 
is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously.

Cost Impact

    There are approximately 1,375 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 912 airplanes of U.S. 
registry would be affected by this proposed AD.
    Should an operator be required to accomplish the proposed 
ultrasonic inspection, it would take approximately 4 work hours per 
airplane to accomplish the inspection, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact of the proposed 
ultrasonic inspection on U.S. operators is estimated to be $240 per 
airplane, per inspection cycle.
    It would take approximately 6 work hours per airplane to accomplish 
the proposed detailed visual and magnetic particle inspections, at the 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed ultrasonic inspection on U.S. operators is 
estimated to be $328,320, or $360 per airplane, per inspection cycle.
    It would take approximately 108 work hours per airplane to 
accomplish the proposed rework of the trunnion fitting, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the proposed rework on U.S. operators is estimated to be 
$5,909,760, or $6,480 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this proposed 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.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Boeing: Docket 2000-NM-18-AD.

    Applicability: All Model 727 series airplanes, 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 (e) 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 failure of the bearing support fitting of the forward 
trunnion, which could result in collapse of the main landing gear 
during normal operations; consequent damage to the airplane 
structure; and injury to flight crew, passengers, or ground 
personnel; accomplish the following:

Interim Inspections/Follow-On Actions

    (a) For airplanes having a bearing support fitting of the 
forward trunnion installed that has NOT been reworked: Within 1,500 
flight cycles or 6 months after the effective date of this AD, 
whichever occurs first; perform an ultrasonic inspection of the 
bearing support fitting of the forward trunnion to detect corrosion 
and cracking in accordance with Part I of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 727-57A0179, Revision 
3, dated September 2, 1999; or Revision 4, dated July 13, 2000, and 
within 18 months after the effective date of this AD, accomplish the 
requirements in paragraph (d) of this AD.
    (b) For airplanes having a bearing support fitting of the 
forward trunnion installed that has been reworked in accordance with 
the Accomplishment Instructions of Boeing Alert

[[Page 48945]]

Service Bulletin 727-57A0179, dated March 8, 1990; Revision 1, dated 
June 13, 1991; Revision 2, dated April 30, 1992; Revision 3, dated 
September 2, 1999; or Revision 4, dated July 13, 2000: Perform an 
ultrasonic inspection of the bearing support fitting of the forward 
trunnion to detect corrosion and cracking in accordance with Part I 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
727-57A0179, Revision 3, dated September 2, 1999; or Revision 4, 
dated July 13, 2000; at the later of the times specified in 
paragraphs (b)(1) and (b)(2) of this AD.
    (1) Within 12,000 flight cycles or 10 years after rework, 
whichever occurs first.
    (2) Within 1,500 flight cycles or 6 months after the effective 
date of this AD, whichever occurs first.

Follow-On Actions/Repetitive Inspections

    (i) If no corrosion or cracking is detected, clean the fitting 
in accordance with the alert service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 1,500 flight cycles or 6 
months, whichever occurs first.
    (ii) If any corrosion or cracking is detected, prior to further 
flight, accomplish the requirements in paragraph (d) of this AD.

Inspections/Rework

    (c) For airplanes having a bearing support fitting of the 
forward trunnion installed that has been reworked in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
727-57A0179, dated March 8, 1990; Revision 1, dated June 13, 1991; 
Revision 2, dated April 30, 1992; Revision 3, dated September 2, 
1999; or Revision 4, dated July 13, 2000: Accomplish the 
requirements in paragraph (d) of this AD at the later of the times 
specified in paragraphs (c)(1) and (c)(2) of this AD.
    (1) Within 12,000 flight cycles or 10 years after rework, 
whichever occurs first.
    (2) Within 36 months after the effective date of this AD.
    (d) At the applicable time specified in paragraph (a), 
(b)(2)(ii), or (c) of this AD, as applicable: Perform detailed 
visual and magnetic particle inspections to detect corrosion and 
cracking of the fitting in accordance with Part II of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 727-
57A0179, Revision 3, dated September 2, 1999, or Revision 4, dated 
July 13, 2000. Rework the fitting in accordance with the alert 
service bulletin and repeat the inspections at intervals not to 
exceed 12,000 flight cycles or 10 years, whichever occurs first. 
Accomplishment of the requirements in this paragraph constitutes 
terminating action for the requirements in paragraph (b) of this AD.

    Note 2: 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.''

Spares

    (e) As of the effective date of this AD, no person shall install 
on any airplane any bearing support fitting of the forward trunnion 
identified in the ``Existing Part Number'' column of Paragraph 2.E. 
of Boeing Alert Service Bulletin 727-57A0179, Revision 4, dated July 
13, 2000, unless that part has been reworked in accordance with Part 
II of the Accomplishment Instructions of the alert service bulletin. 
Verify the part number on the fitting prior to installation, and 
install the subject fitting only if the maximum taxi gross weight 
(MTGW) limit of the fitting is greater than or equal to the MTGW of 
the airplane, in accordance with Boeing Drawing 65C37625, as 
illustrated in the alert service bulletin.

Alternative Methods of Compliance

    (f) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permit

    (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.


    Issued in Renton, Washington, on August 3, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-20246 Filed 8-9-00; 8:45 am]
BILLING CODE 4910-13-P