Source: https://www.federalregister.gov/documents/2005/02/01/05-1794/airworthiness-directives-boeing-model-747-airplanes
Timestamp: 2017-08-20 16:13:34
Document Index: 378652749

Matched Legal Cases: ['§\u200939', 'art 1', 'art 2', 'art 3', 'art 3', 'art 2', 'art 3', 'art 1', 'art 1', 'art 2', 'art 2', 'art 3', 'art 3']

A Proposed Rule by the Federal Aviation Administration on 02/01/2005
We must receive comments on this proposed AD by March 18, 2005.
70 FR 5066
5066-5070 (5 pages)
Docket No. FAA-2005-20243
Directorate Identifier 2004-NM-153-AD
Requirements of AD 2001-13-06:
Inspection for Missing/Broken Fasteners and To Determine Material Type
Ultrasonic Inspection for Damage
Undamaged Fastener: Repetitive Inspections or No Further Action
Repetitive Ultrasonic Inspections and Corrective Actions
https://www.federalregister.gov/d/05-1794 https://www.federalregister.gov/d/05-1794
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 747-100, -200, -300, and 747SP series airplanes. The existing AD currently requires certain inspections to find missing or alloy-steel taperlock fasteners (bolts) in the diagonal brace underwing fittings, and corrective actions if necessary. For airplanes with missing or alloy-steel fasteners, the existing AD also mandates replacement of certain fasteners with new fasteners, which constitutes terminating action for certain inspections. This proposed AD would expand the applicability to include additional airplane models and would require a new inspection to determine fastener material and to find missing or broken fasteners, and related investigative/corrective actions if necessary. This proposed AD is prompted by reports indicating that cracked fasteners made of A286 material were found on airplanes that had only fasteners made of A286 material installed in the area common to the diagonal brace underwing fittings. We are proposing this AD to prevent loss of the underwing fitting load path due to missing or damaged alloy-steel or A286 taperlock fasteners, which could result in separation of the engine and strut from the airplane.
You can examine the contents of this AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2005-20243; the directorate identifier for this docket is 2004-NM-153-AD.
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. FAA-2005-20243; Directorate Identifier 2004-NM-153-AD” at the beginning 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 received by the closing date and may amend the proposed AD in light of those comments.
On June 19, 2001, we issued AD 2001-13-06, amendment 39-12286 (66 FR 34094, June 27, 2001), for certain Boeing Model 747-100, -200, -300, and 747SP series airplanes. That AD requires certain inspections to find missing or alloy-steel taperlock fasteners (bolts) in the diagonal brace underwing fittings; and corrective actions, if necessary. For airplanes with missing or alloy-steel fasteners, that AD also mandates replacement of certain fasteners with new fasteners, which constitutes terminating action for the repetitive inspection. That AD was prompted by a report indicating that broken taperlock fasteners (bolts) were found on the diagonal brace underwing fittings on the outboard strut at the Number 1 and Number 4 engine pylons on a Boeing Model 747-200 series airplane having titanium underwing fittings. We issued that AD to prevent loss of the underwing fitting load path due to missing or damaged alloy-steel taperlock fasteners, which could result in separation of the engine and strut from the airplane.
Since we issued AD 2001-13-06, we have received reports indicating that fractured fasteners have been found on Model 747-200B series airplanes that weren't included in the applicability of the existing AD. The fractured fasteners were made of A286 material, and only fasteners made of that material were installed in the diagonal brace underwing fitting. (After this, this proposed AD refers to fasteners made of A286 material as “A286 fasteners.”) Previously, cracked or broken A286 fasteners were found only on airplanes that had a combination of alloy-steel and A286 fasteners. Thus, these previous incidents were attributed to overload of the A286 fasteners due to Start Printed Page 5067fracture of adjacent alloy-steel bolts. Fractured alloy-steel or A286 fasteners could lead to loss of the underwing fitting load path, which could result in separation of the engine and strut from the airplane.
Alloy-steel or A286 fasteners may be installed in the diagonal brace underwing fitting on certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. Therefore, all of these models and series may be subject to the unsafe condition revealed on the Boeing Model 747-200B series airplanes.
We have reviewed Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004. The service bulletin describes procedures for performing the following actions for the fasteners in the diagonal brace underwing fittings:
A general visual inspection to ensure that all fasteners are installed and unbroken.
A magnetic inspection to determine fastener material.
If any alloy-steel or A286 fastener is found, repetitive ultrasonic inspections for damage of all 10 aft fasteners (regardless of material).
Replacement of damaged fasteners with new, improved fasteners (including an open-hole eddy current inspection for cracking of the fastener holes, and repair if necessary).
Replacement of all alloy steel and A286 fasteners with new, improved fasteners (including an open-hole eddy current inspection for cracking of the fastener holes, and repair if necessary), which eliminates the need for the repetitive inspections.
If any damage is found that exceeds certain limits, the service bulletin recommends contacting Boeing for appropriate action.
We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. This proposed AD would supersede AD 2001-13-06. This proposed AD would retain the requirements of the existing AD. This proposed AD would also expand the applicability of the existing AD and require accomplishing the actions specified in the service bulletin described previously, except as discussed under “Differences Between the Proposed AD and Service Bulletin.”
The service bulletin specifies a magnetic inspection to detect alloy-steel fasteners. We find that a detailed inspection is also necessary to detect A286 fasteners. For the purposes of this AD, an A286 fastener is any fastener to which the magnet is not attracted, and which cannot be conclusively determined to have a part number that begins with BACB30NX (fasteners of T1 material) or BACB30US (fasteners of Inconel material). This difference has been coordinated with the airplane manufacturer, and it agrees with our determination. If Boeing Alert Service Bulletin 747-57A2312 is revised in the future, the new revision will take into account the proposed requirements of this AD.
If any A286 fastener is found during the inspection to determine material type, the service bulletin specifies that you must do an ultrasonic inspection for damage of all 10 aft fasteners in the diagonal brace underwing fitting. However, this proposed AD would require you to perform an ultrasonic inspection for damage of only alloy-steel and A286 fasteners, unless a cracked (or otherwise damaged) fastener is found. If a cracked or otherwise damaged fastener is found, this proposed AD would require ultrasonic inspection for damage of all 10 aft fasteners. This difference has been coordinated with the airplane manufacturer, and it agrees with our determination. If Boeing Alert Service Bulletin 747-57A2312 is revised in the future, the new revision will take into account the proposed requirements of this AD.
Figure 1 of the service bulletin recommends that you perform a general visual inspection to ensure that all fasteners are installed and unbroken. We have determined that the procedures needed for this inspection constitute a detailed inspection. Note 1 of this AD defines a detailed inspection. This difference has been coordinated with the airplane manufacturer, and it agrees with our determination. If Boeing Alert Service Bulletin 747-57A2312 is revised in the future, the new revision will take into account the proposed requirements of this AD.
Section 1.E., Table 1, of the service bulletin specifies an initial inspection threshold of between 11,000 and 29,000 total flight cycles for the inspection to detect A286 fasteners. Section 1.E. of the service bulletin also specifies a grace period of 18 months after the issue date of Revision 1 of the service bulletin. This proposed AD would require compliance prior to the threshold specified in the service bulletin, or within 18 months after the effective date of the AD, whichever occurs later.
Using a method that the Manager of the Seattle Aircraft Certification Office approves; or
Using data that meet the certification basis of the airplane that have been approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the FAA to make those findings.
This proposed AD would retain all requirements of AD 2001-13-06. Since AD 2001-13-06 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:
Requirement in AD 2001-13-06
Paragraph (d) Paragraph (n).
Also, we have changed all references to a “detailed visual inspection” in the existing AD to “detailed inspection” in this action. Note 1 defines a “detailed inspection.”
There are about 739 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, at an average labor rate of $65 per work hour. Start Printed Page 5068
Detailed and magnetic inspection (required by AD 2001-13-06) 2 None $130 60 $7,800
Detailed and magnetic inspections (new proposed action) 3 None 195 140 27,300
2. The FAA amends § 39.13 by removing amendment 39-12286 (66 FR 34094, June 27, 2001) and adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2005-20243; Directorate Identifier 2004-NM-153-AD.
(a) The Federal Aviation Administration must receive comments on this airworthiness directive (AD) action by March 18, 2005.
(b) This AD supersedes AD 2001-13-06, amendment 39-12286 (66 FR 34094, June 27, 2001).
(c) This AD applies to Model 747-100, 747-100B, 747-100B SUD, -200B, 747-200C, 747-200F, 747-300, 747 -400, 747-400D, 747-400F, 747SR, and 747SP series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004.
(d) This AD was prompted by reports indicating that cracked fasteners made of A286 material were found on airplanes that had only fasteners made of A286 material installed in the area common to the diagonal brace underwing fittings. We are issuing this AD to prevent loss of the underwing fitting load path due to missing or damaged alloy-steel or A286 taperlock fasteners, which could result in separation of the engine and strut from the airplane.
(f) For Boeing Model 747-100, 747-200, 747-300, and 747SP series airplanes equipped with titanium diagonal brace underwing fittings, as identified in Boeing Alert Service Bulletin 747-57A2312, dated June 15, 2000: Within 12 months after August 1, 2001 (the effective date of AD 2001-13-06, amendment 39-12286), do a one-time detailed inspection of the diagonal brace underwing fitting at the Number 1 and Number 4 engine pylons to find missing taperlock fasteners (bolts), and a magnetic inspection to find alloy-steel fasteners per Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2312, dated June 15, 2000, or Revision 1, dated April 29, 2004.
(1) If no alloy-steel fasteners are found and no fasteners are missing, no further action is required by this paragraph.
(i) If no damaged alloy-steel fasteners are found, and no fasteners are missing: Repeat the ultrasonic inspection thereafter at intervals not to exceed 18 months until accomplishment of the terminating action required by paragraph (g) of this AD.
(ii) If any damaged alloy-steel fasteners are found, or any fasteners are missing: Before further flight, do an ultrasonic inspection of all 10 aft fasteners (including non-alloy steel) per Part 2 of the Accomplishment Instructions of the service bulletin. Before further flight, replace damaged and missing fasteners with new fasteners per Part 3 of the Accomplishment Instructions of the service bulletin, except as provided by paragraph (l) of this AD. Thereafter, repeat the inspection of the remaining alloy-steel fasteners at intervals not to exceed 18 months until accomplishment of the terminating action required by paragraph (g) or the optional terminating action specified in paragraph (m) of this AD. Start Printed Page 5069
(g) For Boeing Model 747-100, 747-200, 747-300, and 747SP series airplanes equipped with titanium diagonal brace underwing fittings, as identified in Boeing Alert Service Bulletin 747-57A2312, dated June 15, 2000: Within 48 months after August 1, 2001, do the actions required by paragraphs (g)(1) and (g)(2), or (g)(3) of this AD, per Boeing Alert Service Bulletin 747-57A2312, dated June 15, 2000, or Revision 1, dated April 29, 2004. Accomplishment of the actions specified in this paragraph constitutes terminating action for the repetitive inspection requirements of this AD.
(1) Perform an open-hole high frequency eddy current (HFEC) inspection to detect cracks, corrosion, or damage at the bolt hole locations of the aft 10 taperlock fasteners in the diagonal brace underwing fitting at the Number 1 and Number 4 engine pylons per Part 3 of the Accomplishment Instructions of the service bulletin. If any cracking is detected, before further flight, perform applicable corrective actions per the service bulletin, except as provided by paragraph (l) of this AD.
(3) Do an ultrasonic inspection to find damaged fasteners per Part 2 of the Accomplishment Instructions of the service bulletin. Before further flight, replace all damaged non-alloy steel and all alloy-steel fasteners with new fasteners per Part 3 of the Accomplishment Instructions of the service bulletin. Do an open-hole HFEC inspection before installation of the new fasteners; if any cracking, corrosion, or damage is found, before further flight, perform applicable corrective actions per the service bulletin, except as provided by paragraph (l) of this AD.
(h) For all fasteners in the diagonal brace underwing fitting at the Number 1 and Number 4 engine pylons: Perform the inspections in paragraphs (h)(1) and (h)(2) of this AD, as applicable.
(1) For airplanes not identified in paragraph (f) of this AD: Within 12 months after the effective date of this AD, perform a detailed inspection to ensure that all fasteners are installed and unbroken, and a magnetic inspection to detect alloy-steel fasteners, in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004.
(2) For all airplanes: Before the initial inspection threshold specified in Section 1.E., Table 1, of Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004; or within 18 months after the effective date of this AD; whichever is later; perform detailed and magnetic inspections, as applicable, to detect A286 fasteners in the diagonal brace underwing fitting at the Number 1 and Number 4 engine pylons, as specified in Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004. For the purposes of this AD, an A286 fastener is any fastener to which the magnet is not attracted, and which cannot be conclusively determined to be BACB30NX (T1 material) or BACB30US (Inconel material) fasteners.
(i) For all alloy-steel or A286 fasteners identified during the inspections in accordance with paragraph (h) of this AD: Before further flight, perform an ultrasonic inspection for damage (including, but not limited to, cracking or corrosion) of each alloy-steel and A286 fastener, in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004. If any bolt is missing or found damaged during the inspection required by this paragraph: before further flight, perform an ultrasonic inspection for damage of all 10 subject fasteners, in accordance with Part 2 of the Accomplishment Instructions of the service bulletin. Doing the actions required by this paragraph within the compliance time specified in paragraph (f) of this AD eliminates the need to do paragraph (f) of this AD.
(j) For any fastener that is found to be installed and undamaged during the inspections required by paragraph (i) of this AD, do paragraph (j)(1), (j)(2), or (j)(3) of this AD, as applicable.
(1) If no damage is found during the inspections required by paragraph (i) of this AD, and all 10 fasteners in the diagonal brace underwing fitting at the Number 1 and Number 4 engine pylons are either BACB30NX or BACB30US fasteners: No further action is required by this AD, though the restrictions of paragraph (n) of this AD, “Parts Installation,” apply.
(2) For any undamaged alloy steel fastener: Repeat the ultrasonic inspection specified in paragraph (i) of this AD at intervals not to exceed 18 months, until the actions in paragraph (m) of this AD are done.
(3) For any undamaged A286 fastener: Repeat the ultrasonic inspection specified in paragraph (i) of this AD at intervals not to exceed 8,000 flight cycles, until the actions in paragraph (m) of this AD are done.
(k) For any missing or damaged fastener found during the inspections required by paragraph (i) or (j) of this AD: Before further flight, install a new, improved fastener in any location where a fastener is missing, and replace any damaged fastener with a new, improved fastener, in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004. Do an open-hole HFEC inspection for cracking, corrosion, or damage before installing the new fastener. If any cracking, corrosion, or damage is found: Before further flight, perform applicable corrective actions in accordance with the service bulletin, except as provided by paragraph (l) of this AD.
(l) If any damage (including but not limited to cracking or corrosion) of the bolt hole that exceeds the limits specified in Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004, is found during any inspection required by this AD, and the service bulletin specifies to contact Boeing for appropriate action: Before further flight, repair per a method approved by the Manager, Seattle ACO, or according to data meeting the certification basis of the airplane approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who the Manager, Seattle ACO, has authorized to make this finding. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.
(m) Replacement of all alloy steel and A286 fasteners with new, improved fasteners in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2312, Revision 1, dated April 29, 2004 (including performing an open-hole eddy current inspection for cracking of the fastener holes and repairing, as applicable), constitutes terminating action for the repetitive inspection requirements of this AD.
(n) For Boeing Model 747-100, 747-200, 747-300, and 747SP series airplanes equipped with titanium diagonal brace underwing fittings, as identified in Boeing Alert Service Bulletin 747-57A2312, dated June 15, 2000: As of August 1, 2001, no person may install, on any airplane, a fastener having part number BACB30PE( ) * ( ); or any other fastener made of 4340, 8740, PH13-8 Mo, or H-11 steel; in the locations specified in this AD.
(o) Except as provided by paragraph (n) of this AD, as of the effective date of this AD no person may install, on any airplane, a fastener having part number BACB30PE( ) * ( ); or any other fastener made of 4340, 8740, PH13-8 Mo, A286, or H-11 steel; in the locations specified in this AD.
(p)(1) The Manager, Seattle ACO, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.
(3) AMOCs approved previously according to AD 2001-13-06, amendment 39-12286 (66 Start Printed Page 5070FR 34094, June 27, 2001), are approved as AMOCs for the inspection requirements of this AD only at fastener locations where the AMOC provided for installing either BACB30NX or BACB30US fasteners.
Issued in Renton, Washington, on January 21, 2005.
[FR Doc. 05-1794 Filed 1-31-05; 8:45 am]