90-01-12 MCDONNELL DOUGLAS: Amendment 39-6441. Docket No. 89-NM-26-AD. \n\n\tApplicability: 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. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo detect cracks and prevent failures of control columns, accomplish the following: \n\n\tA.\tFor 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): \n\n\nACCUMULATED LANDINGS AS OF\nJULY 30, 1987*\nINITIAL INSPECTION FROM\n JULY 30, 1987 (LANDINGS) \n\n\n60,000 or more\t\n1,500 \n 40,000 to 59,999\t\n2,000 \n30,000 to 39,999\n2,500\n20,000 to 29,999\n3,000 \nUnder 20,000\n3,800 \n\n\t*(July 30, 1987, is the effective date of AD 87-13-04, Amendment 39-5656.) \n\n\tB.\tFor all airplanes: If no cracks are found, accomplish repetitive inspections in accordance with paragraph A., above, at intervals not to exceed 3,800 landings. \n\n\tNOTE: 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. \n\n\tC.\tIf crack(s) are found in either control column (Captain's or First Officer's), accomplish one of the following before further flight: \n\n\t\t1.\tBlend 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 \n\n\t\t2.\tRemove 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 \n\n\t\t3.\tRepair in a manner approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tD.\tReplacement 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. \n\n\tE.\tAn 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. \n\n\tNOTE: 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. \n\n\tAll 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. \n\n\tThis AD supersedes AD 87-13-04, Amendment 39-5656. \n\n\tThis amendment (39-6441, AD 90-01-12) becomes effective on February 5, 1990.