AD 90-25-10

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AD Number:
90-25-10
Document Type:
AD Final Rules
Docket Number:
90-NM-145-AD
Subject Heading:
Airworthiness Directives; BOEING Model 747 Series Airplanes
Subject:
Elevator Control Inspection
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
01/07/1991
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Superseded AD: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Superseded By: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: 90-25-10
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-145-AD

AMENDMENT:   39-6822

AD NUMBER:   90-25-10

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 747 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 7, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-25-10 BOEING: Amendment 39-6822. Docket No. 90-NM-145-AD.

Applicability: Model 747 series airplanes, line numbers 001 through 635, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent loss of redundancy in the elevator control, accomplish the following:

A. For airplanes identified as Group 1 in Boeing Alert Service Bulletin 747-27A2253, Revision 4, dated January 25, 1990, accomplish the following inspections, in accordance with the service bulletin:

1. Prior to the accumulation of 6 years time-in-service, or within the next 6 months after the effective date of this AD, whichever occurs later, visually inspect the inboard elevator power control package (PCP) input rods, inboard elevator control rods, and elevator aft quadrant for corrosion, cracking, and deformation; and repeat thereafter at intervals not to exceed 15 months.

2. Within 15 months after the visual inspection required by paragraph A.1. of this AD, internally borescope inspect the inboard elevator PCP input rods, inboard elevator control rods, and elevator aft quadrant tube for corrosion, cracking, and deformation; and repeat thereafter at intervals not to exceed 30 months.

B. For airplanes identified as Group 2 in Boeing Alert Service Bulletin 747-27A2253, Revision 4, dated January 25, 1990, accomplish the following inspections in accordance with the service bulletin:

1. Prior to the accumulation of 6 total years time-in-service, or within the next 6 months after the effective date of this AD, whichever occurs later, visually inspect the inboard elevator control rods and elevator aft quadrant for corrosion, cracking, and deformation; and repeat thereafter at intervals not to exceed 15 months.

2. Within 15 months after the visual inspection required by paragraph B.1. of this AD, internally borescope inspect the inboard elevator control rods and elevator aft quadrant tube for corrosion, cracking, and deformation; and repeat thereafter at intervals not to exceed 30 months.

C. For airplanes identified as Group 3 in Boeing Alert Service Bulletin 747-27A2253, Revision 4, dated January 25, 1990, accomplish the following inspections in accordance with the service bulletin:

1. Prior to the accumulation of 6 total years time-in-service, or within the next 6 months after the effective date of this AD, whichever occurs later, visually inspect the elevator aft quadrant for corrosion, cracking, and deformation; and repeat thereafter at intervals not to exceed 15 months.

2. Within 15 months after the visual inspection required by paragraph C.1. of this AD, internally borescope inspect the elevator aft quadrant tube for corrosion, cracking, and deformation; and repeat thereafter at intervals not to exceed 30 months.

D. If corrosion is found as a result of the inspections required by paragraphs A., B., or C. of this AD, prior to further flight, accomplish the following:

1. If corrosion is found to be in excess of the allowable limits specified in Boeing Alert Service Bulletin 747-27A2253, Revision 4, dated January 25, 1990, accomplish the terminating modification for the affected component specified in paragraph F. of this AD.

2. If corrosion is found to be within the allowable limits specified in Boeing Alert Service Bulletin 747-27A2253, Revision 4, dated January 25, 1990, refinish in accordance with the service bulletin.

E. If cracks or deformations are found as a result of the inspections required by paragraphs A., B., or C., of this AD, prior to further flight, accomplish the terminating modification for the affected component defined in paragraph F. of this AD.

F. Accomplishment of the terminating modification for all affected components, as specified in Boeing Alert Service Bulletin 747-27A2253, Revision 4, dated January 25, 1990, constitutes termination for the inspections required by paragraphs A., B., and C. of this AD.

G. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle ACO.

H. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

Airworthiness Directive 90-25-10 supersedes AD 85-13-01, Amendment 39-5084.
This amendment (39-6822, AD 90-25-10) becomes effective on January 7, 1991.

FOOTER: