AD 90-01-12

90-01-12 MCDONNELL DOUGLAS: Amendment 39-6441. Docket No. 89-NM-26-AD.

Applicability: Model DC-9-10, -20, -30, -40, -50, and C-9 (Military) series airplanes, fuselage numbers 1 through 757 and 773, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To detect cracks and prevent failures of control columns, accomplish the following:

A. For airplanes not previously inspected in accordance with AD 87-13-04, Amendment 39-5656, prior to the effective date of this amendment: Within 30 days after the effective date of this amendment, or in accordance with the following schedule, whichever occurs later, perform a dye penetrant or eddy current inspection of both control columns, P/N 5614272-1 and 5614272-2 for cracks, in accordance with McDonnell Douglas DC-9 Alert Service Bulletin A27-288, Revision 3, dated July 6, 1989 (hereinafter referred to as A27-288):

ACCUMULATED LANDINGS AS OF JULY 30, 1987* INITIAL INSPECTION FROM JULY 30, 1987 (LANDINGS)

60,000 or more 1,500 40,000 to 59,999 2,000 30,000 to 39,999 2,500 20,000 to 29,999 3,000 Under 20,000 3,800

*(July 30, 1987, is the effective date of AD 87-13-04, Amendment 39-5656.)

B. For all airplanes: If no cracks are found, accomplish repetitive inspections in accordance with paragraph A., above, at intervals not to exceed 3,800 landings.

NOTE: For airplanes previously inspected in accordance with AD 87-13-04, the first repetitive inspection required by this paragraph must be performed within 3,800 landings after the last inspection performed in accordance with AD 87-13-04.

C. If crack(s) are found in either control column (Captain's or First Officer's), accomplish one of the following before further flight:

1. Blend out the cracks up to depths of 0.030 inch, maintaining minimum thickness at the specific inspection area in accordance with Table I of McDonnell Douglas DC-9 Alert Service Bulletin A27-288, using an ultrasonic method, and continually inspect at intervals not exceeding 3,800 landings, until such time as the procedures described in paragraph D., below, are accomplished. If cracks are found after blending, or if a crack(s) is found on any previously blended column, replace the control column with a new production control column, P/N's 5614272-501, -503, SB 09270288-3 (Captain's) or 5614272-502, -504, SB 09276288-4 (First Officer's); or

2. Remove the cracked control column, P/N 5614272-1 (Captain's) or 5614272-2 (First Officer's), and replace it with a new production control column, P/N's 5614272-501, -503, SB 09270288-3, or 5614272-502, -504, SB 09276288-4, respectively, in accordance with McDonnell Douglas Service Bulletin 27-288, dated May 18, 1988; or

3. Repair in a manner approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.

D. Replacement of the Captain's and First Officer's control column, P/N 5614272-1 and 5614272-2, with new control columns, P/N's 5614272-501, -503, SB 09270288-3, and 5614272-502, -504, SB 09270288-4, respectively, constitutes terminating action for the requirements of this amendment.

E. 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, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office.

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: Director of Publications, C1-LOO (54-60). These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California.

This AD supersedes AD 87-13-04, Amendment 39-5656.

This amendment (39-6441, AD 90-01-12) becomes effective on February 5, 1990.