82-04-02 MCDONNELL DOUGLAS: Amendment 39-4317. Applies to all McDonnell Douglas Model DC-9 and C-9 series airplanes, certificated in all categories with rudder pedal arm P/N 3616012 installed with more than 13,500 hours time in service. (Note: Time in service on the rudder pedal arm may be used, if the operator has records to substantiate it.) Compliance required as prescribed herein. To detect fatigue cracking and possible structural failure of the rudder pedal arms, P/N 3616012, accomplish the following, unless already accomplished: \n\n\tA.\tWithin the next 2,000 landings or six months after the effective date of this AD, whichever occurs first, perform ultrasonic and dye penetrant inspections on rudder pedal arm assemblies, P/N 3616012, as outlined in Service Sketch 3251 and Accomplishment Instructions of McDonnell Douglas DC-9 Service Bulletin 27-209 dated May 29, 1981, or later revisions approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region. \n\n\tB.\tIf no cracks are found, replace the rudder pedal arms with new P/N 3953505 aluminum rudder pedal arm assemblies or retain the 3616012 parts and repeat ultrasonic and dye penetrant inspections at intervals not to exceed 4,000 landings or one year, whichever occurs first. Replacement with aluminum rudder pedal arm assemblies constitutes terminating action for this AD. \n\n\tC.\tIf cracks are found, prior to further flight replace the rudder pedal arms with: \n\n\t\t1.\tNew P/N 3953505 aluminum rudder pedal arm assemblies and thereby terminate the repetitive inspection requirements of this AD, or \n\n\t\t2.\tReplace with new P/N 3616012 magnesium rudder pedal arm assemblies, and repeat inspections specified in paragraph B above. \n\n\tD.\tSpecial 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. \n\n\tE.\tFor the purposes of complying with this AD, subject to acceptance by the assigned FAA Maintenance Inspector, the number of landings may be determined by dividing each airplane's number of hours time in service by the operator's fleet average time from takeoff to landing. \n\n\tF.\tUpon the request of an operator, an FAA Maintenance Inspector, subject to prior approval by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region, may adjust the inspection times specified in this AD to permit compliance at an established inspection period of that operator if the request contains substantiating data to justify the change for that operator. \n\n\tG.\tAlternative means of compliance with this AD which provide an equivalent level of safety may be used when approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region. \n\n\tThe manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1).All persons affected by this proposal who have not already received these documents from the manufacturer may obtain copies upon request to the McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director, Publications and Training, C1-750 (54-60). These documents also may be examined at the FAA Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington 98108, or 4344 Donald Douglas Drive, Long Beach, California 90808. \n\n\tThis airworthiness directive becomes effective March 21, 1982.