AD 90-14-07

90-14-07 MCDONNELL DOUGLAS: Amendment 39-6647. Docket No. 90-NM-104-AD.

Applicability: Models DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes, delivered between December 30, 1989, and May 8, 1990, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

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

A. Within 30 days after the effective date of this AD, conduct a visual inspection to determine the date on the elevator control tab identification tag (P/N 5910413-507/-508). The identification tag is located on the inboard side of the second hinge cutout from the inboard end of the control tab.

NOTE: Do not use the date on the P/N 5910413-407/-408 tag, which is similar.

1. Confirm that the elevator control tab assembly has not been changed from that which was delivered on the airplane;

2. If the elevator control tab assembly has been changed since the delivery of the airplane, the identification tag date of the original tab must be ascertained by inspection of the original part.

3. If the date on the identification tag is between December 30, 1989, and May 8, 1990, accomplish the following:

a. Remove access opening door no. 3523A, left-hand, and 3624A, right-hand. (Reference Maintenance Manual 6-23-00, Figure 2.)

b. Check the elevator control tab fitting in the clevis area using Webster pliers, or equivalent per Douglas Process Specification (DPS) 1.05. Non-heat treated (soft) parts will exhibit a reading of less than 10 on the Webster pliers. Properly heat treated parts will have a reading of 10 or greater on Webster pliers, which is equivalent to Rockwell "B" 78-87, Rockwell "E" 103-107, or Brinell 126-147.

NOTE: Remove all paint and primer locally before using Webster pliers. An invalid reading will be obtained if any paint remains in the indentation area.

NOTE: Do not use conductivity readings as a methodof acceptance.

B. If the fittings are properly heat treated, no further action is required.

C. If the fittings have a Webster pliers reading of less than 10, before further flight, remove the fittings and replace them with fittings exhibiting a Webster pliers reading of 10 or greater.

D. If only one fitting per airplane is found to be soft, 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.

E. Any elevator control tab fitting, P/N 5937825-1/-2, that fails the hardness test specified in paragraph A.3.b., above, shall not be subsequently installed on any airplane, unless the fitting is heat treated to meet the requirements in paragraph A.3.b.

F. Replacement of the elevator control tab fittings with those exhibiting a Webster pliers reading of 10 or greater, constitutes an acceptable alternate means of compliance with the requirements 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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

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

All persons affected by this directive who have not already received the appropriate service information 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). This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229 EastSpring Street, Long Beach, California.

This amendment (39-6647, AD 90-14-07) becomes effective on July 23, 1990.