Source: http://www.thefederalregister.com/d.p/2005-02-14-05-2762
Timestamp: 2013-05-22 07:06:46
Document Index: 584418147

Matched Legal Cases: ['art 7114', 'art 3944', 'art 6726', 'art 140', 'art 5250', 'art 1739', 'art 30206', 'art 514', 'art 9740', 'art 180', 'art 1', 'art 1', 'art 4', 'art 4', 'art 3', 'art 4', 'art 2', 'art 4', 'art 3', 'art 2', 'art 1', 'art 2', 'art 2', 'art 1', 'art 4', 'art 4', 'art 2', 'art 4', 'art 3', 'art 2', 'art 1', 'art 4', 'art 4', 'art 2', 'art 4', 'art 3', 'art 3', 'art 7', 'art 4', 'art 4', 'art 3', 'art 3', 'art 5', 'art 6', 'art 5', 'art 6', 'art 7', 'art 1', 'arts 1', 'arts 3', 'arts 1', 'art 2', 'arts 1', 'art 2']

14 CFR Part 7114 CFR Part 3944 CFR Part 6726 CFR Part 140 CFR Part 5250 CFR Part 1739 CFR Part 30206 CFR Part 514 CFR Part 9740 CFR Part 180	Federal Register: February 14, 2005 (Volume 70, Number 29)
DOCID: FR Doc 05-2762
Docket ID: [Docket No. FAA-2005-20364; Directorate Identifier 2004-NM-186-AD]
SUBJECT CATEGORY: Airworthiness Directives; Boeing Model 747 Airplanes DATES: We must receive comments on this proposed AD by March 31, 2005.
DOCUMENT SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747 airplanes. This proposed AD would require repetitive inspections of the dual side braces (DSBs), underwing midspar fittings, and associated parts; other specified actions; and corrective actions if necessary. This proposed AD also provides an optional terminating action for the inspections and other specified actions. This proposed AD is prompted by reports of corroded, migrated, and rotated bearings for the DSBs in the inboard and outboard struts, a report of a fractured retainer for the eccentric bushing for one of the side links of a DSB, and reports of wear and damage to the underwing midspar fitting on the outboard strut. We are proposing this AD to prevent the loss of a DSB or underwing midspar fitting load path, which could result in the transfer of loads and motion to other areas of a strut, and possible separation of a strut and engine from the airplane during flight.
Comments Invited We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include ``Docket No. FAA200520364; Directorate Identifier 2004NM186AD'' in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments. We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 1947778), or you can visit http://dms.dot.gov. Examining the Docket You can examine the AD docket on the Internet at http://dms.dot.gov , or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647
5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them. Discussion We have received reports of corroded, migrated, and rotated bearings for the dual side braces (DSBs) in the inboard and outboard struts, a report of a fractured retainer for the eccentric bushing for one of the side links of a DSB, and reports of wear and damage to the underwing midspar fitting on the outboard strut on Boeing Model 747400 and Model 747SP series airplanes. These conditions, if not corrected, could result in the loss of the DSB or underwing midspar fitting load path, which could result in the transfer of loads and motion to other areas of a [[Page 7447]]
strut, and possible separation of a strut and engine from the airplane during flight. The subject area on certain Boeing Model 747100, 747100B, 747
100B SUD, 747200B, 747200C, 747200F, 747300, 747400D, 747400F, and 747SR series airplanes is of a similar type design to those on the affected Model 747400 and 747SP series airplanes. Therefore, all of these models may be subject to the same unsafe condition.
We have reviewed Boeing Alert Service Bulletin 74754A2218, dated June 17, 2004. The service bulletin describes procedures for repetitive inspections of the DSBs, underwing midspar fittings, and associated parts; other specified actions; and corrective actions if necessary. This proposed AD also provides an optional terminating action for the repetitive actions. The service bulletin specifies that the initial inspections of the DSBs and of the underwing midspar fitting be done within 24 months after the release date of the service bulletin. The service bulletin also specifies that the initial corrosion removal and relubrication of the DSB bearings be done within 72 months after the release date of the service bulletin (unless directed by the findings of the initial inspections of the DSBs to be done earlier). The service bulletin specifies that repetitive intervals range between 24 months and 72 months for the aforementioned actions. The service bulletin also specifies that the corrective actions be done before further flight or within 24 months of finding certain conditions. The service bulletin specifies that the following actions for the inboard and outboard struts are applicable to Groups 13 airplanes, and that only the actions for the inboard struts are applicable to Group 4 airplanes:
Part 1Dual Side Brace Inspections
The service bulletin describes the following DSB inspections:
Do a detailed inspection of the bearing spherical ball for corrosion, corrosion pitting, and corrosion products.
Do a detailed inspection for migration and rotation of the bearing outer race.
Do a detailed inspection for cracks or fracture of the eccentric bushing retainer. The service bulletin specifies that if no discrepancies are found during the inspections, either repeat Part 1 and Part 4, or do Part 4 and Part 3 (terminating action). The service bulletin specifies that if any discrepancies are found during the inspections, the corrective actions include doing Part 4 and Part 2; or doing Part 4 and Part 3 (terminating action); as applicable.
The service bulletin also specifies that Part 2 may be done instead of Part 1.
Part 2Bearing Corrosion Removal and ReLubrication
The service bulletin describes the following inspections and rework of the DSB bearings and associated parts, and other specified actions.
Do a detailed inspection of the bearing for migration and rotation.
Do a detailed inspection for cracks or fracture of the swaged lips.
Do a detailed inspection for cracks or fracture of the eccentric bushing retainer.
Do a detailed inspection of the eccentric bushing for damage.
Do a detailed inspection of the bushing and fuse pin for damage.
Do a detailed inspection of the bolt for damage.
The other specified actions include determining if the amount of play in the bearing exceeds specified limits, determining if corrosion exceeds specified limits, and removing corrosion, as applicable; and lubricating the spherical ball and inside of the outer race. The service bulletin specifies that if no discrepancies are found during the actions specified in Part 2: Either repeat both Part 1 and Part 4, and Part 4 and Part 2; or do Part 4 and Part 3 (terminating action). The service bulletin specifies that if any discrepancies are found during the actions specified in Part 2, the corrective actions include repeating both Part 1 and Part 4, and Part 4 and Part 2; or doing Part 4 and Part 3 (terminating action); as applicable. The corrective actions also include replacing any damaged bushings/eccentric bushings/
fuse pins/bolts with new or serviceable bushings/eccentric bushings/
fuse pins/bolts; and contacting Boeing for additional instructions.
Part 3Dual Side Brace Bearing Replacement and Side Link Modification
The service bulletin describes procedures for replacing the strut and wing side DSB bearings with new or serviceable strut and wing side bearings (includes, for Groups 3 and 4, installing cups per Part 7), modifying side links, and doing related investigative and corrective actions. Related investigative actions include the following inspections:
Detailed inspection of the fuse pin for damage.
Detailed inspection for damage of the strut fitting lug bore and chamfers.
Fluorescent penetrant inspection (FPI) or high frequency eddy current inspection for cracks of the strut fitting lug bore and chamfers.
Detailed inspection for cracking of the swaged lip of the bearing.
FPI of the eccentric bushing bore in the link for cracks, corrosion, and damage.
Detailed inspection of the bushing for damage.
Corrective actions include replacing any damaged fuse pin with a new or serviceable fuse pin; contacting Boeing for additional instructions; oversizing the lug bore; and replacing any damaged bearing with a new or serviceable bearing.
Part 4Underwing Midspar Fitting Inspection
The service bulletin describes an inspection to determine the gap between the underwing midspar fitting and strut midspar fitting.
The service bulletin specifies that if the gap is within limits specified in the service bulletin no further action is required.
The service bulletin specifies that if the gap is not within limits specified in the service bulletin, the corrective action includes doing Part 4 and Part 3 (terminating action) or doing Part 3, Part 5, and Part 6 (terminating action), as applicable.
Part 5Underwing Midspar Fitting Inspection and Rework
The service bulletin describes procedures to do a detailed inspection of the underwing midspar fitting lugs, strut spring beam lugs and bushings, and strut fitting lugs for damage, and corrective action if necessary. The corrective action includes reworking the underwing midspar fitting, spring beams, and strut fitting; and contacting Boeing for additional instructions.
Part 6Dual Side Brace Fitting and Underwing Midspar Fitting Tension Bolt Inspection The service bulletin describes procedures to do a detailed inspection of the dual side brace fitting and underwing fittings for missing or fractured tension bolts or for broken sealant around the fasteners; and do a detailed inspection of the visible areas of the underwing fitting lugs and strut fitting lugs or spring beam lugs for damage; and corrective action if necessary. The corrective action is [[Page 7448]]
repairing any damage and contacting Boeing for additional instructions. Part 7Vapor Seal Web Cup Installation The service bulletin describes procedures for Groups 3 and 4 to install cups for the vapor seal web. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.
We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under ``Differences Between the AD and the Service Bulletin.'' The FAA is not proposing to mandate the optional terminating action for several reasons: 1. Accessing the areas for inspection at the intervals is easily accomplished. 2. The inspection items are easily performed by means of a detailed inspection. 3. Longterm continued operational safety in this case will be adequately ensured by repetitive inspections to prevent the loss of a DSB or underwing midspar fitting load path.
There are about 1,091 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.
Average Cost per U.S.
Action Work hours labor rate Parts airplane registered Fleet cost
per hour airplanes Part 1 Inspections, per inspection 8 $65 None................ $520 229 $119,080, per inspection cycle. cycle.
Inspections, per inspection 48 65 None................ 3,120 229 714,480, per inspection cycle. cycle.
Inspections, per inspection 4 65 None................ 260 229 59,540, per inspection cycle. cycle.
The FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. Subtitle I, Section 106 describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the agency's authority. This rulemaking is promulgated under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, ``General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
Boeing: Docket No. FAA200520364; Directorate Identifier 2004NM 186AD. Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by March 31, 2005. Affected ADs (b) None. Applicability
(c) This AD applies to Boeing Model 747100, 747100B, 747100B SUD, 747200B, [[Page 7449]]
747200C, 747200F, 747300, 747400, 747400D, 747400F, 747SR, and 747SP series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 74754A2218, dated June 17, 2004. Unsafe Condition
(d) This AD was prompted by reports of corroded, migrated, and rotated bearings for the dual side braces (DSB) in the inboard and outboard struts, a report of a fractured retainer for the eccentric bushing for one of the side links of a DSB, and reports of wear and damage to the underwing midspar fitting on the outboard strut. We are issuing this AD to prevent the loss of a DSB or underwing midspar fitting load path, which could result in the transfer of loads and motion to other areas of a strut, and possible separation of a strut and engine from the airplane during flight. Compliance
(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Inspections and Corrective Action
(f) At the times specified in Figure 1 of Boeing Alert Service Bulletin 74754A2218, dated June 17, 2004, except as provided by paragraph (g) of this AD: Do the various inspections and other specified actions in the figure to detect discrepancies of the dual side braces, underwing midspar fittings, and associated parts, by doing all of the actions specified in Parts 1, 2, and 4; and the applicable corrective actions specified in Parts 3, 5, 6, and 7; of the Accomplishment Instructions of the service bulletin, except as provided by paragraph (h) of this AD. Repeat the inspections and other specified actions thereafter at the intervals specified in Figure 1 of the service bulletin. Accomplishment of any terminating action specified in Figure 1 of the service bulletin terminates the inspections and other specified actions.
(g) Where Boeing Alert Service Bulletin 74754A2218, dated June 17, 2004, recommends an initial compliance threshold of ``within 24 months after the original issue date on this service bulletin'' for Parts 1 and 4 of the service bulletin, and of ``within 72 months after the original issue date on this service bulletin'' for Part 2 of the service bulletin, this AD requires an initial compliance threshold of ``within 24 months after the effective date of this AD'' for Parts 1 and 4 of the service bulletin and of ``within 72 months after the effective date of this AD'' for Part 2 of the service bulletin.
(h) If any damage or crack is found during any inspection or corrective action required by this AD, before further flight, repair in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 74754A2218, dated June 17, 2004; except, where the service bulletin specifies to contact Boeing, before further flight, repair according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. Alternative Methods of Compliance (AMOCs)
(2) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. Issued in Renton, Washington, on February 7, 2005. Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 052762 Filed 21105; 8:45 am]