AD 91-11-02

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AD Number:
91-11-02
Document Type:
AD Final Rules
Docket Number:
90-NM-263-AD
Subject Heading:
Airworthiness Directives; McDONNELL DOUGLAS DC-9-81, -82, -83 and -87 (MD-81, -82, -83 and -87) Seri...Show more
Subject:
Engine Mount Nuts
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/24/1991
Make:
The Boeing Company
Model:
DC-9-81 (MD-81) | DC-9-82 (MD-82) | DC-9-83 (MD-83) | DC-9-87 (MD-87) | MD-88
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Superseded AD: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Superseded By: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: 91-11-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-263-AD

AMENDMENT:   39-6998

AD NUMBER:   91-11-02

SUBJECT HEADING:   Airworthiness Directives; McDONNELL DOUGLAS DC-9-81, -82, -83 and -87 (MD-81, -82, -83 and -87) Series Airplanes and Model MD-88 Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective June 24, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-11-02 McDONNELL DOUGLAS: Amendment 39-6998. Docket No. 90-NM-263-AD. Supersedes AD 90-12-51.

Applicability: Model DC-9-81, -82, -83 and -87 (MD-81, -82, -83 and -87) series airplanes and Model MD-88 airplanes, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent damage to the engine, cone bolts, and pylon, or separation of an engine from the airplane, as a result of the loss of a through-bolt, accomplish the following:

A. Within seven days after August 29, 1990 (the effective date of Amendment 39-6684, AD 90-12-51), inspect the through-bolt nut, P/N SPS83978-1216, for proper torque and conditions in accordance with McDonnell Douglas MD-80 Alert Service Bulletin A71-51, dated May 23, 1990. If any of the following discrepancies are found, take corrective action as required below:

CONDITION A: If the torque stripe is misaligned, prior to further flight, accomplish the following:

I. Remove and replace the nut in accordance with paragraph C. of this AD, and

II. Apply a new torque stripe.

CONDITION B: If the torque stripe is aligned properly, within 10 calendar days, verify that the torque on the nut is 250 inch-pounds (in-lb) or more.

I. If the torque is 250 in-lb or more, remove and replace the torque stripe.

II. If the torque is less than 250 in-lb, reinstall the nut in accordance with paragraph C. of this AD and apply a new torque stripe.

CONDITION C: If the torque stripe is missing, and the nut is seated, and the through-bolt head is seated and positioned properly (there is no gap between the nut base and washer, or the washer and engine mount flange bushing, or the through-bolt head and retainer, or the retainer and engine mount flange bushing), within 10 calendar days, apply 30 in-lb of torque:

I. If the nut turns remove and replace the nut in accordance with paragraph C. of this AD and apply a new torque stripe.

II. If the nut does not turn, torque to the required range of 250 in-lb to 300 in-lb, and apply a new torque stripe.

CONDITION D: If the torque stripe is missing and there is a gap between the nut base and washer, or the washer and engine mount flange bushing, or the through-bolt head and retainer, or the retainer and engine mount flange bushing; prior to further flight, apply 30 in-lb of torque:

I. If the nut turns, remove and replace the nut in accordance with paragraph C. of this AD and apply a new torque stripe.

II. If the nut does not turn, torque to the required range of 250 in-lb to 300 in-lb, and apply a new torque stripe.

CONDITION E: If the nut is missing and the through-bolt has not migrated, prior to further flight, install a new nut in accordance with paragraph C. of this AD and apply a new torque stripe.

CONDITION F: If the nut is missing and the through-bolt is missing or partially backed-out, prior to further flight, repair in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.

B. Repeat the inspections required by paragraph A. of this AD at intervals not to exceed 30 calendar days; except that, if the torque stripe is aligned properly, the corrective action identified in Condition B, above, is not required.

C. Nut installation method and requirements:

1. Remove and replace the nut.

2. Remove the existing torque stripe.

3. Ensure that the through-bolt head is properly positioned and in place.

4. Measure the running torque of the nut on the through-bolt. If the running torque is less than 30 in-lb or more than 100 in-lb, discard the nut and replace it with a new nut. If the running torque is 30 in-lb or more but less than 100 in-lb, continue with the installation procedure.

5. Ensure that the final installation torque is at least 250 in-lb but less than 300 in-lb.

D. Within 10 days after performing the initial inspection required by paragraph A. of this AD, submit a report of any discrepancies to the Manager, Los Angeles Manufacturing Inspection District Office, 3229 East Spring Street, Long Beach, California 90806-2425. The report must include the airplane's serial number.

E. Within 18 months after the effective date of this AD, install castellated nuts and cotter pins in accordance with McDonnell Douglas MD-80 Service Bulletin 71-51, dated September 28, 1990. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of this AD.

F. An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager of the Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles ACO.

G. 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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Business Unit Manager of Publications, C1-HCO (54-60). These documents may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California.

This amendment supersedes Amendment 39-6684, AD 90-12-51 which superseded AD T90-11-52, issued on May 24, 1990.

This amendment (39-6998, AD 91-11-02) becomes effective on June 24, 1991.


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