[Federal Register Volume 68, Number 243 (Thursday, December 18, 2003)]
[Proposed Rules]
[Pages 70477-70479]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-31180]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-335-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 and 720 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 certain Boeing Model 707 and 720 
series airplanes. This proposal would require repetitive inspections of 
the upper and lower barrel nuts and bolts that retain the aft trunnion 
support fitting of each main landing gear for corrosion, cracks, and 
loose or missing nuts and bolts; torque checks of the upper and lower 
bolts to verify the torque is within a specified range; and corrective 
actions, if necessary. This action is necessary to detect and correct 
cracking and/or loss of the barrel nuts and bolts that retain the aft 
trunnion support fitting, which could result in the collapse of the 
main landing gear upon landing. This action is intended to address the 
identified unsafe condition.

DATES: Comments must be received by February 2, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-335-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 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. 2002-NM-335-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 or 2000 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

[[Page 70478]]

Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Candice Gerretsen, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6428; fax (425) 917-6590.

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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-335-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. 2002-NM-335-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that one operator found 
cracks in the barrel nut that attaches the aft trunnion bearing cap of 
the main landing gear to the trunnion support fitting and that another 
operator discovered that the barrel nut and bolt were missing, on 
Boeing Model 707 series airplanes. The cause of the cracking is stress 
corrosion. This condition, if not detected and corrected, could result 
in cracking and/or loss of the barrel nuts and bolts that retain the 
aft trunnion support fitting, which could result in the collapse of the 
main landing gear upon landing.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing 707/720 Alert Service 
Bulletin A3509, dated June 13, 2002, which describes procedures for 
performing repetitive detailed inspections of the upper and lower 
barrel nuts and bolts that retain the aft trunnion support fitting of 
each main landing gear for corrosion, cracks, and loose or missing nuts 
and bolts; torque checks of the upper and lower bolts to verify the 
torque is within the specified range; and corrective actions, if 
necessary. The corrective actions consist of performing a detailed 
inspection of the aft trunnion bearing cap and aft trunnion support 
fitting for corrosion, and repair if necessary; performing a magnetic 
particle inspection of the aft trunnion bearing cap for cracks, and 
replacement if necessary; and reinstalling the main landing gear 
trunnion with new Inconel barrel nuts and bolts to retain the aft 
trunnion support fitting. Accomplishment of the actions specified in 
the 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 service bulletin described previously.

Cost Impact

    There are approximately 230 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 42 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed detailed inspection of the upper and lower barrel nuts and 
bolts and the torque check. The average labor rate is $65 per work 
hour. Based on these figures, the cost impact on U.S. operators is 
estimated to be $2,730, or $65 per airplane, per inspection and torque 
check.
    It would take approximately 3 work hours per airplane to accomplish 
the proposed detailed inspection of the aft trunnion bearing cap. The 
average labor rate is $65 per work hour. Based on these figures, the 
cost impact on U.S. operators is estimated to be $8,190, or $195 per 
airplane.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed installation of the new Inconel barrel nut and bolt and 
the main landing gear trunnion. The average labor rate is $65 per work 
hour. Based on these figures, the cost impact on U.S. operators is 
estimated to be $10,920, or $260 per airplane.
    Required parts would cost approximately $3,380 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

[[Page 70479]]

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 2002-NM-335-AD.

    Applicability: Model 707 and 720 series airplanes, as listed in 
Boeing 707/720 Alert Service Bulletin A3509, dated June 13, 2002; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct cracking and/or loss of the upper and 
lower barrel nuts and bolts that retain the aft trunnion support 
fitting, which could result in the collapse of the main landing gear 
upon landing, accomplish the following:

Service Bulletin References

    (a) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing 707/720 Alert Service Bulletin 
A3509, dated June 13, 2002.

Initial Inspection

    (b) Within 60 days after the effective date of this AD, for each 
main landing gear, perform the inspection specified in paragraph 
(b)(1) of this AD and the torque check specified in paragraph (b)(2) 
of this AD, in accordance with the service bulletin.
    (1) Perform a detailed inspection of the upper and lower barrel 
nuts and bolts that retain the aft trunnion support fitting for 
corrosion, cracks, and loose or missing nuts and bolts.
    (2) Torque check the upper and lower bolts to verify the torque 
is within the range specified in Figure 2 of the service bulletin.

Repetitive Inspections

    (c) If no corrosion, crack, or loose or missing nut or bolt is 
found, and the torque is found to be within the specified range, 
during the inspection and torque check specified in paragraph (b) of 
this AD, then repeat the actions specified in paragraph (b) of this 
AD thereafter at intervals not to exceed 60 days.

Corrective Actions

    (d) If any corrosion, crack, or loose or missing nut or bolt is 
found, or if the torque is found not to be within the specified 
range, during the inspection and torque check specified in paragraph 
(b) of this AD: Before further flight, do the corrective actions 
specified in paragraphs (d)(1) through (d)(3) of this AD. 
Accomplishment of these actions constitutes terminating action for 
the repetitive inspections specified in paragraph (c) of this AD.
    (1) Perform a detailed inspection of the aft trunnion bearing 
cap and aft trunnion support fitting for corrosion, in accordance 
with the service bulletin. If any corrosion is detected, before 
further flight, repair in accordance with the service bulletin.
    (2) Perform a magnetic particle inspection of the aft trunnion 
bearing cap for cracks in accordance with Figure 3 of the service 
bulletin.
    (i) If no crack is found, before further flight, reinstall the 
inspected aft trunnion bearing cap in accordance with the service 
bulletin.
    (ii) If any crack is found, before further flight, replace the 
aft trunnion bearing cap with a new aft trunnion bearing cap in 
accordance with the service bulletin.
    (3) Reinstall the main landing gear trunnion with new Inconel 
barrel nuts and bolts to retain the aft trunnion support fitting, in 
accordance with Figure 4 of the service bulletin.

Terminating Action

    (e) Within one year after the effective date of this AD, for 
each main landing gear, replace the upper and lower steel barrel 
nuts and H-11 bolts that retain the aft trunnion support fitting 
with new Inconel barrel nuts and bolts as specified in paragraphs 
(d)(1) through (d)(3) of this AD. Accomplishment of these actions 
constitutes terminating action for the requirements of this AD.

Parts Installation

    (f) As of the effective date of this AD, no person shall install 
a steel barrel nut with H-11 bolt to retain the aft trunnion support 
fitting, on any airplane.

Alternative Methods of Compliance

    (g) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Issued in Renton, Washington, on December 10, 2003.
Kevin Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-31180 Filed 12-17-03; 8:45 am]
BILLING CODE 4910-13-U