AD 96-16-08

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 727-100 and -200 series airplanes. This action requires an inspection to detect discrepancies of internal wires and electrical components of the control box of the main deck cargo door; modification of the wiring and components of the control box of the main deck cargo door; and a revision of the Airplane Flight Manual to impose an operational limitation of the motor pump power relay and pump motor. This amendment is prompted by results of an engineering review of the wiring diagram of the main deck cargo door installations, which revealed potential failures of the control box and hydraulic pump assembly installed in accordance with the STC. The actions specified in this AD are intended to prevent such failures, which could result in an inadvertent opening of the main deck cargo door during flight, with resultant major structural damage and possible reduced controllabilityof the airplane.

Final rule; request for comments

96-16-08 BOEING: Amendment 39-9708. Docket 96-NM-157-AD. \n\n\tApplicability: Model 727-100 and -200 series airplanes that have been modified in accordance with Supplemental Type Certificate (STC) SA1797SO, certificated in any category.\n \n\tNOTE 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 (d) 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent the inadvertent opening of the main deck cargo door during flight, which could result in major structural damage and possible reduced controllability of the airplane, accomplish the following: \n\n\t(a)\tAccomplish the actions specified in paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this AD at the time specified in each of those paragraphs: \n\n\t\t(1)\tWithin 3 days after the effective date of this AD, perform a visual inspection of internal wires and electrical components of the control box of the main deck cargo door to detect the following discrepancies: \n\n\t\t\t(i)\tchafed, crimped, crushed, or damaged electrical wires or wire bundles inside the control box of the cargo door; \n\t\t\t(ii)\tloose electrical wire connections; \n\t\t\t(iii)\tabnormally pulled or twisted individual wires or wire bundles; \n\t\t\t(iv)\tany removal of insulation from the conductor in the control box; or \n\t\t\t(v)\tany damaged protective grommets. \n\n\t\t(2)\tIf any discrepancy is detected during the inspection required by paragraph (a)(1) of this AD, prior to further flight, repair it in accordance with a method approved by the Manager, FAA, Atlanta Aircraft Certification Office (ACO), Small Airplane Directorate. \n\n\t\t(3)\tFollowing accomplishment of paragraphs (a)(1) and, if applicable, (a)(2) of this AD, verify that the wire and wire bundles are properly installed and restrained, and reinstall and restrain any wire or component that has been altered, in accordance with the document identified in either paragraph (a)(3)(i) or (a)(3)(ii) of this AD. \n\n\t\t\t(i)\tSection 1 ("Care of Electrical System"); Section 3 ("Electric Wire"); Section 5 ("Connectors"); and Section 7 ("Routing, Tying, Lacing, and Clamping"); of Chapter 11 ("Electrical Systems") of FAA Advisory Circular AC 43.13-1A, Change 3, dated 1988; or \n\n\t\t\t(ii)\tChapter 20 ("Standard Wiring Practices") of Boeing Wiring Diagram Manual Document D6-54446, Revision 21,dated June 1, 1994. \n\n\t\t(4)\tWithin 10 days after accomplishing the inspection required by paragraph (a)(1) of this AD, submit a report of the inspection results (both positive and negative findings) to the Manager, FAA, Atlanta Aircraft Certification Office, Small Airplane Directorate, Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; telephone (404) 305-7381; fax (404) 305-7348. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. \n\n\t(b)\tWithin 3 days after the effective date of this AD, revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following statement. This may be accomplished by inserting a copy of this AD in the AFM. \n\n\t\t\t"Operational Restriction \n\n\tPrior to taxi, verify that the alternating current (AC) or direct current (DC) circuit \t\tbreakers that supply electrical power to the hydraulic pump motor are PULLED to \t\tinterrupt power to the motor pump power relay and pump motor. \n\n\tNOTE: The 28VDC circuit breaker is located in the electrical equipment compartment \ton the J9 battery shield panel next to the auxiliary power unit (APU) starter circuit \t\tbreaker. The 115VAC circuit breakers are located on the P6 breaker panel to the right \tof the Flight Engineers station. These circuit breakers are identified as "Cargo Door \tHydraulic Pump". \n\n\tPrior to each taxi and take-off after closing the cargo door, set these circuit breakers to \tan open condition. Tag and secure the circuit breakers for flight. \n\n\tAfter landing and taxiing to the ramp, the circuit breakers may be RESET to facilitate \n\tcargo door opening." \n\n\t(c)\tWithin 90 days after the effective date of this AD, modify the wiring and components of the control box of the main deck cargo door, in accordance with a method approved by the Manager, FAA, Atlanta Aircraft Certification Office (ACO), Small Airplane Directorate. \n\n\t(d)\tAn 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, FAA, Atlanta Aircraft Certification Office (ACO), Small Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO. \n\n\t(e)\tSpecial 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. \n\n\t(f)\tCertain actions shall be done either in accordance with Sections 1, 3, 5, and 7 of Chapter 11 ("Electrical Systems") of FAA Advisory Circular (AC) 43.13-1A, Change 3, dated 1988; or in accordance with Chapter 20 ("Standard Wiring Practices") of Boeing Wiring Diagram Manual Document D6-54446, Revision 21, dated June 1, 1994. Sections 1, 3, 5, and 7 of Chapter 11 of FAA Advisory Circular AC 43.13-1A contain the following list of effective pages: \n\n\nReferenced\nSection\nPage Number\nChange Level\nShown on Page\nDate\nShown on Page \nSection 1, "Care of Electrical Systems" \n173-174\nOriginal\n1972\nSection 3, "Electric "Wire"\n179, 180, 180-1,\n180-2, 181, 181-1, \n181-2, 182, 182-1, \n182-2, 183-185, \n185-1, 185-2, 186, \n188, 188-1, 188-2 \n\n187, 189-193\n3\n\n\n\n\n\n\nOriginal\n1988\n\n\n\n\n\n\n1972 \nSection 5, "Connectors"\t\n196, 200\n\n197-199\n3\n\nOriginal\n1988 \n\n1972\nSection 7, "Routing, Tying, Lacing, and Clamping"\n203, 204, 206-209\n\n205, 205-1,\n205-2 \nOriginal\n\n3\n1972\n\n1988\n\nChapter 20 of Boeing Wiring Diagram Manual Document D6-54446 contains the following list of effective pages: \n\n\n\nPage Title and Number\nDate\nShown on Page \nTitle Page\nDecember 1, 1991 \nRevision Transmittal Pages 1-6\nJune 1, 1994 \nRevision Record Pages 1, 2\nDecember 1, 1991 \nTemporary Revision Record\nPages 1, 2 \nDecember 1, 1991 \nList of Effective Pages 1-30\nJune 1, 1994 \n\nThis incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of Boeing Manufacturing Drawing D65446 may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies of FAA Advisory Circular (AC) 43.13-1A may be obtained from Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402. Copies of all of these documents may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at FAA, Atlanta Aircraft Certification Office, Small Airplane Directorate, Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(g)\tThis amendment becomes effective on August 27, 1996.

The FAA recently conducted an engineering review of the wiring diagram of the main deck cargo door installations on Boeing Model 727-100 and -200 series airplanes that have been modified in accordance with Supplemental Type Certificate (STC) SA1797SO. The results of this review revealed the existence of two unsafe conditions related to the control box and hydraulic pump assembly installed on these airplanes: \n\n\t1. Due to the close proximity to the relays, a 28-volt wire could become chafed as a result of vibration and, consequently, could short to power a single DC relay (AN 3311-2). This short to power could energize the DC relay and simultaneously apply electrical power to the hydraulic pump motor and to the control valve of the main deck cargo door. \n\n\t2. Failure of an electrical relay on the 115-volt AC power circuit could cause the hydraulic pump motor to become energized and, consequently, produce full hydraulic pressure in the pump. Such available pressure could unlock the main deck cargo door. \n\n\tThese conditions, if not corrected, could result in an inadvertent opening of the main deck cargo door during flight, which could result in major structural damage and possible reduced controllability of the airplane. \n\nExplanation of Relevant Service Information \n\n\tThe FAA has issued Advisory Circular (AC) 43.13-1A, Change 3, dated 1988, which contains the following sections of Chapter 11 ("Electrical Systems"): \n\n\t1. Section 1 ("Care of Electrical Systems"), \n\t2. Section 3 ("Electrical Wire"), \n\t3. Section 5 ("Connectors"), and \n\t4. Section 7 ("Routing, Tying, Lacing, and Clamping"). \n\n\tThe FAA also has reviewed and approved Chapter 20, "Standard Wiring Practices," of Boeing Wiring Diagram Manual Document D6-54446, Revision 21, dated June 1, 1994. \n\n\tThese documents describe procedures for verifying that the wire and wire bundles are properly installed and restrained, and for reinstalling and restraining anywire or component that has been altered. \n\nExplanation of the Requirements of the Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other Boeing Model 727-100 and -200 series airplanes of the same type design, equipped with a main deck cargo door installed in accordance with STC SA1797SO, this AD is being issued to prevent an inadvertent opening of the main deck cargo door during flight, which can result in major structural damage and possible reduced controllability of the airplane. This AD requires the following actions: \n\n\t1. Performing a one-time visual inspection of the internal wires and electrical components of the control box of the main deck cargo door to detect discrepancies, and repair, if necessary. (These discrepancies include chafed, crimped, crushed, or damaged electrical wires or wire bundles inside the control box of the cargo door; loose electrical wire connections; abnormally pulled or twisted individual wires or wire bundles; any removal of insulation from the conductor in the control box; and any damaged protective grommets.) \n\n\t2. Verifying that the wire and wire bundles are properly installed and restrained; and reinstalling and restraining any wire or component that has been altered. \n\n\t3. Submitting a report of the inspection results (both positive and negative findings) to the FAA. \n\n\t4. Revising the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to impose an operational limitation of the motor pump power relay and pump motor. This limitation requires the flight crew to verify that certain circuit breakers supplying electrical power to the hydraulic pump motor are pulled prior to taxi. It also requires that, prior to each taxi and takeoff after closing the cargo door, these circuit breakers are set to the open condition, tagged, and secured for flight. \n\n\t5. Modifying the wiring and components of the control box of the main deck cargo door to preclude the identified problems. Aeronautical Engineers, Inc. (AEI), which is the holder of the subject STC, currently is developing a change to the wiring diagram that will address this. \n\n\tCertain of the actions are required to be accomplished in accordance with the documents described previously. Certain other actions are required to be accomplished in accordance with a method approved by the FAA. Determination of Rule's Effective Date \n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.\n\n Comments Invited \n\n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule bysubmitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 96-NM-157-AD." The postcard will be date stamped and returned to the commenter. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \n\n\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nAdoption of the Amendment \n\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 - (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: