AD 93-17-07

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AD Number:
93-17-07
Document Type:
AD Final Rules
Docket Number:
93-NM-71-AD
Subject Heading:
Airworthiness Directives; BOEING Model 747 Series Airplanes
Subject:
Spring Beam Aft Lugs
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
09/10/1993
Make:
The Boeing Company
Model:
747-100 Series | 747-100B Series | 747-100B SUD Series | 747-200B Series | 747-200C Series | 747-200...Show more
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Superseded AD: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Superseded By: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
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 93-17-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   93-NM-71-AD

AMENDMENT:   39-8678

AD NUMBER:   93-17-07

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 747 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective September 10, 1993.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
93-17-07 BOEING: Amendment 39-8678. Docket 93-NM-71-AD. Supersedes AD 93-01-04, Amendment 39-8458 which superseded AD 85-22-07, Amendment 39-5153.

Applicability: All Model 747 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the failure of the engine support structure and the inability of the strut to carry required engine support loads, accomplish the following:

RESTATEMENT OF ACTIONS REQUIRED BY AD 85-22-07, AMENDMENT 39- 5153:

(a) INITIAL/REPETITIVE INSPECTIONS: For Model 747 series airplanes listed in Boeing Service Bulletin 747-54-2100, dated June 20, 1983: Perform an ultrasonic inspection of the inboard and outboard midspar fitting lugs or spring beam aft lugs of each strut to detect cracks in accordance with Boeing Service Bulletin 747-54-2100, dated June 20, 1983; Revision 1, dated August 25, 1988; Revision 2, dated July 20, 1989; or Revision 3, dated November 16, 1989; at the time specified in paragraph (a)(1), (a)(2), (a)(3), or (a)(4) of this AD, as applicable. Repeat that inspection thereafter at intervals not to exceed 3,000 landings until the inspections required by paragraph (b) of this AD is accomplished.

(1) For airplanes that have accumulated less than 30,000 total hours time-in- service as of November 24, 1985 (the effective date of AD 85-22-07, Amendment 39-5153): Inspect within 18 months after November 24, 1985, or prior to the accumulation of 25,000 total hours time-in-service, whichever occurs later.

(2) For airplanes that have accumulated 30,000 or more total hours time-in- service, but less than 40,000 total hours time-in-service, as of November 24, 1985 (the effective date of AD 85-22-07, Amendment 39-5153): Inspect within 12 months after November 24, 1985.

(3) For airplanes that have accumulated 40,000 or more total hours time-in- service as of November 24, 1985 (the effective date of AD 85-22-07, Amendment 39-5153): Inspect within 6 months after November 24, 1985.

(4) For airplanes on which the midspar fitting or its lug bushings have been replaced, or on which the spring beam or its aft lug bushings have been replaced: Inspect those lugs within 18 months after November 24, 1985 (the effective date of AD 85-22-07, Amendment 39-5153), or within 25,000 total hours time-in-service after such replacement, whichever occurs later.

RESTATEMENT OF ACTIONS REQUIRED BY AD 93-01-04, AMENDMENT 39- 8458:

(b) INITIAL INSPECTIONS: For airplanes equipped with midspar fitting lugs or spring beam aft lugs that do not have roller-swaged, shrink-fitted bushings: Perform an ultrasonic inspection to detect cracks of the midspar fitting lugs or spring beam aft lugs of each strut and a detailed visual inspection to detect corrosion of the lugs and bushing migration, in accordance with Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, or Revision 1, dated July 15, 1993, prior to the times specified in paragraphs (b)(1) and (b)(2) of this AD. After the effective date of this AD, these inspections shall only be accomplished in accordance with Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993. Accomplishment of these inspections terminates the repetitive inspection requirement of paragraph (a) of this AD.

(1) Inspect inboard engine positions 2 and 3 prior to the later of the times specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this AD.

(i) Prior to the accumulation of 5,000 landings on the midspar fitting lugs, or within 5 years since installation, whichever occurs first. Or

(ii) Within 60 days after February 5, 1993 (the effective date of AD 93-01-04, Amendment 39-8458).

(2) Inspect outboard engine positions 1 and 4 prior to the later of the times specified in paragraphs (b)(2)(i) and (b)(2)(ii) of this AD.

(i) Prior to the accumulation of 5,000 landings on the midspar fitting lugs or spring beam aft lugs, or within 5 years since installation, whichever occurs first. Or

(ii) Within 90 days after February 5, 1993 (the effective date of AD 93-01-04, Amendment 39-8458).

(c) INITIAL INSPECTIONS: For airplanes equipped with midspar fitting lugs or spring beam aft lugs having roller-swaged, shrink-fitted bushings: Perform a detailed visual inspection of the midspar fitting lugs or spring beam aft lugs of each strut for corrosion of the lugs and bushing migration in accordance with Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, or Revision 1, dated July 15, 1993, prior to the later of the times specified in paragraphs (c)(1) and (c)(2) of this AD.

(1) Prior to the accumulation of 5,000 landings on the midspar fitting lugs or spring beam aft lugs, or within 5 years since installation, whichever occurs first. Or

(2) Within 90 days after February 5, 1993 (the effective date of AD 93-01- 04, Amendment 39-8458).

(d) REPETITIVE INSPECTIONS: Repeat the inspection required by paragraph (b) or (c) of this AD, as applicable, prior to the times specified in paragraphs (d)(1) and (d)(2) of this AD, as applicable, in accordance with Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, or Revision 1, dated July 15, 1993, until the inspections required by paragraphs (e) and (f) of this AD are accomplished, as applicable.

(1) For midspar fitting lugs: At intervals not to exceed 1,000 landings.

(2) For spring beam aft lugs: At intervals not to exceed 3,000 landings.

NEW ACTIONS REQUIRED BY THIS AMENDMENT

(e) INITIAL INSPECTIONS FOR LUGS RE-WORKED IN ACCORDANCE WITH BOEING SERVICE BULLETIN 747-54-2100: For airplanes equipped with midspar fitting lugs or spring beam aft lugs that were last re-worked in accordance with Boeing Service Bulletin 747-54-2100: Perform an ultrasonic inspection to detect cracks of the midspar fitting lugs or spring beam aft lugs of each strut and a detailed visual inspection to detect corrosion of the lugs and bushing migration and rotation in accordance with Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993, prior to the times specified in paragraphs (e)(1) and (e)(2) of this AD, as applicable. Accomplishment of these inspections terminates the repetitive inspection requirements of paragraph (d) of this AD.

(1) For airplanes that have been inspected previously in accordance with AD 93-01-04: Perform the inspections prior to the times specified in paragraphs (e)(1)(i), (e)(1)(ii), and (e)(1)(iii) of this AD, as applicable.

(i) For midspar fitting lugs installed on the inboard strut on Groups 1, 4, and 9 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: Within 500 landings since the previous ultrasonic or detailed visual inspection, or within 60 days after the effective date of this AD, whichever occurs later.

(ii) For midspar fitting lugs installed on the inboard strut other than those subject to the requirements of paragraph (e)(1)(i) of this AD; and for midspar fitting lugs installed on the outboard strut on Groups 1 and 4 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: Within 1,000 landings since the previous ultrasonic or detailed visual inspection, or within 90 days after the effective date of this AD, whichever occurs later.

(iii) For spring beam aft lugs: Within 3,000 landings since the previous ultrasonic or detailed visual inspection, or within 90 days after the effective date of this AD, whichever occurs later.

(2) For airplanes that have not been inspected previously in accordance with AD 93-01-04: Perform the inspections prior to the times specified in paragraphs (e)(2)(i), (e)(2)(ii), and (e)(2)(iii) of this AD, as applicable.

(i) For midspar fitting lugs installed on the inboard strut on Groups 1, 4, and 9 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: Inspect prior to the later of the times specified in paragraphs (e)(2)(i)(A) and (e)(2)(i)(B) of this AD.

(A) Prior to the accumulation of 2,500 landings on the re-worked midspar fitting lugs, or within 3 years since re-work of the lugs, whichever occurs first. Or

(B) Within 60 days after the effective date of this AD.
(ii) For midspar fitting lugs and spring beam aft lugs other than those subject to the requirements of paragraph (e)(2)(i) of this AD: Inspect prior to the later of the times specified in paragraphs (e)(2)(ii)(A) and (e)(2)(ii)(B) of this AD.

(A) Prior to the accumulation of 5,000 landings on the re-worked midspar fitting lugs, or within 5 years since re-work of the lugs, whichever occurs first. Or

(B) Within 90 days after the effective date of this AD.
(f) INITIAL INSPECTIONS FOR LUGS OTHER THAN THOSE RE-WORKED IN ACCORDANCE WITH BOEING SERVICE BULLETIN 747-54-2100: For airplanes equipped with midspar fitting lugs or spring beam aft lugs other than those subject to the requirements of paragraph (e) of this AD: Perform an ultrasonic inspection to detect cracks of the midspar fitting lugs or spring beam aft lugs of each strut and a detailed visual inspection to detect corrosion of the lugs and bushing migration and rotation in accordance with Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993, prior to the times specified in paragraphs (f)(1) and (f)(2) of this AD, as applicable. Accomplishment of these inspections terminates the repetitive inspection requirements of paragraph (d) of this AD.
(1) For airplanes that have been inspected previously in accordance with AD 93-01-04: Perform the inspections prior to the times specified in paragraphs (f)(1)(i), (f)(1)(ii), and (f)(1)(iii) of this AD, as applicable.

(i) For midspar fitting lugs installed on the inboard strut on Groups 1, 4, and 9 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: Within 500 landings since the previous ultrasonic or detailed visual inspection, or within 60 days after the effective date of this AD, whichever occurs later.

(ii) For midspar fitting lugs installed on the inboard strut other than those subject to the requirements of paragraph (e)(1)(i) of this AD; and for midspar fitting lugs installed on the outboard strut on Groups 1 and 4 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: Within 1,000 landings since the previous ultrasonic or detailed visual inspection, or within 90 days after the effective date of this AD, whichever occurs later.

(iii) For spring beam aft lugs: Within 3,000 landings since the previous ultrasonic or detailed visual inspection, or within 90 days after the effective date of this AD, whichever occurs later.

(2) For airplanes that have not been inspected previously in accordance with AD 93-01-04: Perform the inspections prior to the times specified in paragraphs (f)(2)(i) and (f)(2)(ii) of this AD, as applicable.

(i) For midspar fitting lugs installed on the inboard strut on Groups 1, 4, and 9 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: Inspect prior to the later of the times specified in paragraphs (f)(2)(i)(A) and (f)(2)(i)(B) of this AD.

(A) Prior to the accumulation of 5,000 landings on the midspar fitting lugs, or within 5 years since installation, whichever occurs first. Or

(B) Within 60 days after the effective date of this AD.

(ii) For midspar fitting lugs other than those subject to the requirements of paragraph (f)(2)(i) of this AD, and for spring beam aft lugs: Inspect prior to the later of the times specified in paragraphs (f)(2)(ii)(A) and (f)(2)(ii)(B) of this AD.

(A) Prior to the accumulation of 5,000 landings on the lugs, or within 5 years since installation, whichever occurs first. Or

(B) Within 90 days after the effective date of this AD.

(g) REPETITIVE INSPECTIONS: Repeat the inspections required by paragraphs (e) and (f) of this AD, as applicable, prior to the times specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, as applicable, in accordance with Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993.

(1) For midspar fitting lugs installed on the inboard strut on Groups 1, 4, and 9 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: At intervals not to exceed 500 landings.

(2) For midspar fitting lugs installed on the inboard strut other than those subject to the requirements of paragraph (g)(1) of this AD; and for midspar fitting lugs installed on the outboard strut on Groups 1 and 4 airplanes, as listed in Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993: At intervals not to exceed 1,000 landings.

(3) For spring beam aft lugs: At intervals not to exceed 3,000 landings.

CORRECTIVE ACTIONS

(h) MIGRATED OR ROTATED BUSHINGS: If any migrated or rotated bushing is found as a result of any inspection required by this AD, prior to further flight, re-seal the bushing in accordance with Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, or Revision 1, dated July 15, 1993. Prior to the accumulation of 1,000 additional landings after detecting the migrated or rotated bushing, re-work the midspar fitting or spring beam, as applicable, in accordance with Figure 5 of the service bulletin. Reinspection of the lug bore, which is part of the lug re-work procedure, shall only be accomplished using magnetic particle inspection techniques. After the effective date of this AD, re-work of the midspar fitting or spring beam shall only be accomplished in accordance with Boeing Alert Service Bulletin 747- 54A2152, Revision 1, dated July 15, 1993.

(i) CRACKS: If any crack is found in the lugs as a result of any inspection required by this AD, prior to further flight, replace the affected midspar fitting or spring beam in accordance with Boeing Service Bulletin 747-54-2100, dated June 20, 1983; Revision 1, dated August 25, 1988; Revision 2, dated July 20, 1989; or Revision 3, dated November 16, 1989.

(j) CORROSION: If any corrosion is found as a result of any inspection required by this AD, prior to further flight, remove the corrosion in accordance with Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, or Revision 1, dated July 15, 1993.

(k) Any midspar fitting or spring beam replaced in accordance with the procedures described in Boeing Service Bulletin 747-54-2100, dated June 20, 1983; Revision 1, dated August 25, 1988; Revision 2, dated July 20, 1989; or Revision 3, dated November 16, 1989, shall be considered to be a new midspar fitting or spring beam. Any midspar fitting or spring beam that has been re-worked in accordance with Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, or Revision 1, dated July 15, 1993, shall also be considered to be a new midspar fitting or spring beam. Replaced or re-worked fittings or spring beams are subject to the initial inspections required by paragraphs (e) and (f) of this AD, as applicable, and any subsequent corrective actions based on the findings of those inspections.

NOTE 1: Midspar fittings or spring beams that have been re-worked in accordance with Boeing Service Bulletin 747-54-2100, dated June 20, 1983; Revision 1, dated August 25, 1988; Revision 2, dated July 20, 1989; or Revision 3, dated November 16, 1989, are not to be considered to be new midspar fittings or spring beams. In addition, the initial inspection threshold for these lugs is less than the initial inspection threshold for lugs that have been re-worked in accordance with Boeing Alert Service Bulletin 747-54A2152.

(l) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(m) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(n) The inspections, re-seal, re-work, corrosion removal, and replacements shall be done in accordance with Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993; Boeing Service Bulletin 747-54-2100, dated June 20, 1983; Boeing Service Bulletin 747- 54-2100, Revision 1, dated August 25, 1988; Boeing Service Bulletin 747-54-2100, Revision 2, dated July 20, 1989; Boeing Service Bulletin, Revision 3, dated November 16, 1989; and Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992; as applicable. The incorporation by reference of Boeing Alert Service Bulletin 747-54A2152, Revision 1, dated July 15, 1993, was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. The incorporation by reference of Boeing Service Bulletin 747-54-2100, dated June 20, 1983; Boeing Service Bulletin 747-54-2100, Revision 1, dated August 25, 1988; Boeing Service Bulletin 747-54-2100, Revision 2, dated July 20, 1989; Boeing Service Bulletin, Revision 3, dated November 16, 1989; and Boeing Alert Service Bulletin 747-54A2152, dated December 23, 1992, 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 5, 1993 (58 FR 483, January 6, 1993). 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.

(o) This amendment becomes effective on September 10, 1993.

FOOTER: