AD 97-14-04 Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes

Models named: 737-100, -200, -300, -400, -500 series. Read the applicability below — it usually turns on serial or part numbers too.

All Model 737-100, -200, -300, -400, and -500 series airplanes, certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (i) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To prevent uncommanded movements of the rudder, and consequent reduced controllability of the airplane, accomplish the following: Restatement of Requirements of AD 94-01-07 (a) Within 750 flight hours after March 3, 1994 (the effective date of AD 94-01-07, amendment 39-8789), perform a test of the main rudder PCU, part number 65-44861-2/-3/-4/-5/-6/-7/-8/-9, to detect internal leakage of hydraulic fluid, in accordance with Boeing Service Letter 737-SL-27-82-B, dated July 13, 1993. (1) If no discrepancy, as described in paragraph 3.B. of the Service Letter, is detected, repeat the test at intervals not to exceed 750 flight hours. (2) If any discrepancy, as described in paragraph 3.B. of the Service Letter, is detected during any check, prior to further flight, accomplish either paragraph (a)(2)(i) or (a)(2)(ii) of this AD: (i) Replace the main rudder PCU with a serviceable PCU in accordance with the Model 737 Overhaul Manual. After such replacement, repeat the test at intervals not to exceed 750 flight hours. (ii) Replace the main rudder PCU with a new main rudder PCU having part number 65-44861-11 or 65C37052-2/-3/-4/-5/-6/-7/-8/-9, in accordance with Boeing Service Bulletin 737-27-1185, dated April 15, 1993. Such replacement constitutes terminating action for the tests required by paragraph (a) of this AD. (b) Replacement of the main rudder PCU, part number 65-44861-( ), with a new main rudder PCU having part number 65-44861-11 or 65C37052-2/-3/-4/-5/-6/-7/-8/-9, in accordance with Boeing Service Bulletin 737-27-1185, dated April 15, 1993, constitutes terminating action for the tests required by paragraph (a) of this AD. Restatement of Requirements of AD 96-23-51 (c) Within 10 days after November 27, 1996 (the effective date of AD 96-23-51, amendment 39-9818), perform a test to verify proper operation of the rudder PCU, in accordance with Boeing Alert Service Bulletin 737-27A1202, dated November 1, 1996, or Revision 1, dated December 6, 1996. (1) If the rudder PCU operates properly, repeat the test thereafter at intervals not to exceed 250 flight hours. (2) If the rudder PCU operates improperly, prior to further flight, replace the rudder PCU with a new rudder PCU, in accordance with the alert service bulletin. Repeat the test thereafter at intervals not to exceed 250 flight hours. New Requirements of This AD (d) Within 2 years after the effective date of this AD, accomplish paragraphs (d)(1) and (d)(2) of this AD in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Accomplishment of these actions terminates the requirements of paragraphs (a), (b), and (c) of this AD. (1) Replace any main rudder PCU having Boeing part number (P/N) 65-44861-() or P/N 65C37052-() with a new main rudder PCU that has been approved by the Manager, Seattle ACO. (2) Replace the vernier control rod bolts having Boeing P/N 69- 27229-() with new bolts that have been approved by the Manager, Seattle ACO. (e) Perform a leak test of the main rudder PCU in accordance with a method approved by the Manager, Seattle ACO, at the applicable times specified in paragraph (e)(1) or (e)(2) of this AD. If any discrepancy is found, prior to further flight, replace the PCU with a serviceable or newly designed unit in accordance with a method approved by the Manager, Seattle ACO. Note 2: If the PCU is replaced in accordance with the requirements of paragraph (e) prior to accomplishing the replacement required by paragraph (d) of this AD, ``serviceable'' includes the newly designed PCU referenced in paragraph (d)(1) of this AD and PCU's having part number 65-44861-11 and 65C37052-2, -3, -4, -5, -6, -7, -8, and -9. However, after the PCU has been replaced in accordance with paragraph (d)(1) of this AD, ``serviceable'' is limited to the newly designed PCU's referenced in that paragraph. (1) For airplanes on which the replacement specified in paragraph (a)(2)(ii), (b), or (c)(2) of this AD has been accomplished prior to the effective date of this AD: Within 4,000 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 6,400 flight hours. (2) For airplanes other than those identified in paragraph (e)(1) of this AD: Within 6,400 flight hours after accomplishment of the replacement required by paragraph (d)(1) of this AD, and thereafter at intervals not to exceed 6,400 flight hours. (f) Revision of the FAA-approved maintenance program to require an FAA-approved leak test constitutes terminating action for the repetitive leak test requirements of paragraph (e) of this AD. (g) Once a newly designed PCU specified in paragraph (d)(1) of this AD is installed on an airplane, no operator shall install on that airplane any PCU other than such a newly designed unit. (h) Once a newly designed vernier control rod bolt specified in paragraph (d)(2) of this AD is installed on an airplane, no operator shall install on that airplane any bolt other than such a newly designed bolt. (i) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (j) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. (k) The actions shall be done in accordance with Boeing Service Letter 737-SL-27-82-B, dated July 13, 1993; Boeing Alert Service Bulletin 737-27A1202, dated November 1, 1996; and Boeing Alert Service Bulletin 737-27A1202, Revision 1, dated December 6, 1996. The incorporation by reference of Boeing Service Letter 737-SL-27- 82-B, dated July 13, 1993, as listed in the regulations, was approved previously by the Director of the Federal Register as of March 3, 1994 (59 FR 4570, February 1, 1994). The incorporation by reference of Boeing Alert Service 737-27A1202, dated November 1, 1996, as listed in the regulations, was approved previously by the Director of the Federal Register as of November 27, 1996 (61 FR 59317, November 22, 1996). The incorporation by reference of Boeing Alert Service Bulletin 737-27A1202, Revision 1, dated December 6, 1996, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may [[Page 35072]] be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (l) This amendment becomes effective on August 4, 1997. Issued in Renton, Washington, on June 23, 1997. S.R. Miller, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-16852 Filed 6-27-97; 8:45 am] BILLING CODE 4910-13-U