AD 95-10-13

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AD Number:
95-10-13
Document Type:
AD Final Rules
Docket Number:
94-NM-188-AD
Subject Heading:
Airworthiness Directives; Boeing Model 757 Series Airplanes
Subject:
Forward Support Bracket
Status:
Current
Citation:
(Federal Register: May 16, 1995 (Volume 60, Number 94))
Citation Publish Date:
05/16/1995
Effective Date:
02/28/1994
Make:
The Boeing Company
Model:
757-200 Series | 757-200CB Series | 757-200PF Series | 757-300 Series
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 (60 FR 25983 NO. 94 5/16/95)
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 95-10-13
CITATION:   [Federal Register: May 16, 1995 (Volume 60, Number 94)]

PAGE NUMBER:   [Page 25983]

DOCKET NUMBER:   94-NM-188-AD

AMENDMENT:   39-9230

AD NUMBER:   95-10-13

SUBJECT HEADING:   Airworthiness Directives; Boeing Model 757 Series Airplanes

ACTION:   Final rule

SUMMARY:  
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that currently requires inspections to detect fatigue- related cracking or breakage of the hydraulic tubing support brackets located on the upper spar web in the engine struts; further inspection to detect related damage of the upper spar web, the fuel lines, and the hydraulic lines, as necessary; and repair or replacement of cracked or damaged parts. That AD was prompted by reports of fatigue-related cracks in the hydraulic tubing support brackets located on the upper spar web in the engine struts. The actions specified by that AD are intended to prevent such fatigue-related cracking, which could result in fuel or hydraulic fluid leakage into the interior of the engine strut and cause a fire. This amendment requires installation of a previously optional terminating action.

DATES:   Effective June 15, 1995. The incorporation by reference of Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993, as listed in the regulations was approved previously by the Director of the Federal Register as of February 28, 1994 (59 FR 6542).

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:  
Sheila Kirkwood, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2675; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:  
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 94-04-04, amendment 39-8822 (59 FR 11182, March 10, 1994), which is applicable to certain Boeing Model 757 series airplanes, was published in the Federal Register on December 29, 1994 (59 FR 67240). The action proposed to supersede AD 94- 04-04 to continue to require inspections to detect fatigue-related cracking or breakage of the hydraulic tubing support brackets located on the upper spar web in the engine struts; further inspection to detect related damage of the upper spar web, the fuel lines, and the hydraulic lines, as necessary; and removal, and either repair or replacement of cracked or damaged parts. That action also proposed to require replacement of all existing support brackets manufactured from 2219 aluminum, 2024-T42 aluminum alloy, or 301 stainless steel with new nickel alloy support brackets; this replacement would constitute terminating action for the repetitive inspection requirements.

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

One commenter supports the proposed rule.

One commenter requests that the FAA revise the proposal to allow support brackets manufactured from 2219 aluminum, 2024-T42 aluminum alloy, or 301 stainless steel to be replaced with either new brackets made of 17-7PH steel or new brackets made of nickel alloy. The commenter states that it previously received FAA approval of an alternative method of compliance with AD 94-04-04 for installation of new brackets made of 17-7PH steel. This commenter notes that it would be burdensome to have to request FAA approval for another alternative method of compliance with this AD for an action already accomplished. The FAA concurs and has revised paragraph (f) of the final rule accordingly.

One commenter requests that references in the proposed rule to "nickel alloy brackets" be changed to read "nickel alloy 625 brackets" in order to avoid confusion with other nickel alloy possibilities. The FAA concurs and revised all references accordingly throughout this final rule.

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.

There are approximately 132 Boeing Model 757 series airplanes equipped with Rolls Royce engines of the affected design in the worldwide fleet. The FAA estimates that 102 airplanes of U.S. registry will be affected by this AD.

The actions currently required by AD 94-04-04 take approximately 4 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the total cost impact of the currently required actions on U.S. operators is estimated to be $24,480, or $240 per airplane.

The replacement actions take approximately 40 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $1,044 per airplane. Based on these figures, the total cost impact of the required replacement actions on U.S. operators is estimated to be $351,288, or $3,444 per airplane.

The total cost impact figure discussed above is based on assumptions that no 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 regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. § 39.13 - [Amended]

2. Section 39.13 is amended by removing amendment 39-8822 (59 FR 11182, March 10, 1994), and by adding a new airworthiness directive (AD), amendment 39-9230, to read as follows:

REGULATORY TEXT:  
95-10-13 BOEING: Amendment 39-9230. Docket 94-NM-188-AD. Supersedes AD 94-04-04, Amendment 39-8822.

Applicability: Model 757 series airplanes equipped with Rolls Royce engines; as listed in Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993; 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 use the authority provided in paragraph (h) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent fuel or hydraulic fluid leakage into the interior of the engine strut, which could cause a fire, accomplish the following:

(a) For Group 2 Airplanes: Within 60 days after February 28, 1994 (the effective date of AD 94-04-04, amendment 39-8822), perform an inspection using a magnet to determine whether the forward support bracket for the hydraulic tubing on the upper spar web of each engine strut is manufactured from 17-7PH steel, in accordance with Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993. If any forward support bracket is manufactured from 17-7PH steel, no further action is required by this AD for that forward bracket.

NOTE 2: The brackets positioned after the forward bracket should be manufactured from 17- 7PH steel, as shown below:

Bracket	Part Number	(Power Plant Station Number )
First Bracket	312N5817-13 (or equivalent)	PPS 102
Second Bracket	312N5817-19 (or equivalent)	PPS 120
Third Bracket	312N5817-23 (or equivalent)	PPS 129
Fourth Bracket	312N5817-25 (or equivalent)	PPS 145

(b) For Groups 1 and 2 Airplanes: Within 60 days after February 28, 1994 (the effective date of AD 94-04-04, amendment 39-8822) (for Group 1 airplanes), and prior to further flight following the inspection required by paragraph (a) of this AD (for Group 2 airplanes), perform an initial visual inspection to detect fatigue-related cracks or breakage on the hydraulic tubing support brackets not manufactured of 17-7PH steel on the upper spar web of each engine strut, in accordance with Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993. If any discrepancy is detected, prior to further flight, accomplish the following in accordance with the alert service bulletin:

(1) For any support bracket that is completely broken: Perform a further visual inspection to detect worn areas or other damage of the upper spar web, the fuel lines, and the hydraulic lines; and prior to further flight, accomplish paragraphs (b)(1)(i), (b)(1)(ii), (b)(1)(iii), and (b)(1)(iv) of this AD in accordance with the alert service bulletin:

(i) Repair any damaged upper spar web.
(ii) Repair or replace any damaged fuel line with new or
serviceable parts, as necessary.
(iii) Replace any damaged hydraulic line with new or serviceable
parts.
(iv) Remove any broken support bracket; and, except as provided
by paragraph (c) of this AD, replace it with a new nickel alloy 625 bracket.
(2) For any support bracket that is cracked, but not completely broken: Perform a further visual inspection to detect damage of the hydraulic pressure line only; and prior to further flight, accomplish paragraphs (b)(2)(i) and (b)(2)(ii) of this AD in accordance with the alert service bulletin:

(i) Replace any damaged hydraulic pressure line with new or serviceable parts, as necessary.

(ii) Remove any cracked support bracket; and, except as provided by paragraph (c) of this AD, replace it with a new nickel alloy 625 bracket.

(c) For any airplane having a support bracket that is removed during accomplishment of paragraph (b)(1)(iv) or (b)(2)(ii) of this AD: The following number of flights are permitted prior to replacement of any removed support bracket with a new nickel alloy 625 bracket (in accordance with Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993), provided that, prior to further flight, the cracked or broken brackets are removed completely, damaged spar webs are repaired, and fuel lines and hydraulic lines are repaired or replaced, in accordance with paragraph (b) of this AD:

Part Number
Bracket
	
(Power Plant Station Number)
	
Flights Permitted

First Bracket Removed	P/N 312N5817-55 (PPS 102)	No Flights
Second Bracket Removed	P/N 312N5817-69 (PPS 120)	Ten Flights
Third Bracket Removed	P/N 312N5817-73 (PPS 129)	Ten Flights
Fourth Bracket Removed	P/N 312N5817-75 (PPS 145)	Three Flights
Second and Third Brackets Removed		One Flight
Multiple Brackets, other than Second and Third		No Flights

(d) For any airplane having a support bracket that is manufactured from 2024-T42 aluminum alloy or 301 stainless steel: Repeat the initial inspection required by paragraph (b) of this AD thereafter at intervals not to exceed 2,000 flight hours, in accordance with the procedures described in Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993.

(e) For any airplane having a support bracket that is manufactured from 2219 aluminum: Repeat the initial inspection required by paragraph (b) of this AD thereafter at intervals not to exceed 1,000 flight hours, in accordance with the procedures described in Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993.

(f) Within 18 months after the effective date of this AD: Replace all support brackets manufactured from 2219 aluminum, 2024-T42 aluminum alloy, or 301 stainless steel, with either new 17-7PH steel brackets or new nickel alloy 625 support brackets for the hydraulic tubing on the upper spar web of the engine struts at all locations, in accordance with Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993. Accomplishment of this modification constitutes terminating action for the requirements of this AD.

(g) As of February 28, 1994 (the effective date of AD 94-04-04, amendment 39-8822), no person shall install any hydraulic tubing support bracket on the upper spar web of the engine struts that is manufactured from 2219 aluminum, 2024-T42 aluminum alloy, or 301 stainless steel on any airplane.

(h) 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.

(i) 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.

(j) The inspections, repair, replacement, and removal shall be done in accordance with Boeing Alert Service Bulletin 757-54A0030, Revision 1, dated December 20, 1993. The incorporation by reference of this document was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of February 28, 1994 (59 FR 65420). 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.

(k) This amendment becomes effective on June 15, 1995.

FOOTER: