Airworthiness Directive · Amendment 39-14134 · Boeing Model 757 Series Airplanes
Boeing Model 757 Series Airplanes
All Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 757 series airplanes. For certain affected airplanes, this action requires repetitive testing of the secondary brakes of the horizontal stabilizer trim actuator (HSTA). For all affected airplanes, this action requires repetitive overhauls of the primary brake and differential assembly of the HSTA, which would constitute terminating action for the repetitive testing of the secondary brake. This action is necessary to prevent grease contamination on the primary HSTA brake and consequent loss of the primary brake function, which, in combination with the loss of the secondary HSTA brake function, could result in loss of control of the airplane. This action is intended to address the identified unsafe condition.
To prevent grease contamination on the primary horizontal stabilizer trim actuator (HSTA) brake and consequent loss of the primary brake function, which, in combination with the loss of the secondary HSTA brake function, could result in loss of control of the airplane, accomplish the following:
(a) For Model 757-200, -200CB, and -200PF series airplanes: Except as provided by paragraphs (c), (d), and (e) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 757-27A0142, Revision 2, dated October 23, 2003; including the compliance time “since the most recent overhaul of the primary brake, the ballscrew assembly, and the differential assembly”; do the actions specified in paragraphs (a)(1) and (a)(2) of this AD.
(1) Test the secondary brakes of the HSTA in accordance with Part 2 of the Accomplishment Instructions of the service bulletin. If any secondary brake fails, before further flight, replace with a serviceable brake or overhaul in accordance with Part 2 of the Accomplishment Instructions of the service bulletin.
(2) Overhaul the primary brake and differential assembly of the HSTA in accordance with Part 1 of the Accomplishment Instructions of the service bulletin. Accomplishment of the overhaul constitutes terminating action for the repetitive tests of the secondary brake required by paragraph (a)(1) of this AD.
(b) Repeat the overhaul of the primary brake and differential assembly of the HSTA at intervals not to exceed 30,000 flight hours, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0142, Revision 2, dated October 23, 2003.
(c) Where the service bulletin specified in paragraph (a) of this AD specifies a date from which the initial compliance time interval starts as being the date of the initial release of the service bulletin, this AD requires compliance within the applicable initial compliance time after the effective date of this AD.
(d) Where the service bulletin specified in paragraph (a) of this AD states “total hours since delivery,” this AD requires compliance prior to the accumulation of the applicable number of flight hours since the date of issuance of the original Airworthiness Certificate or the date of issuance of the original Export Certificate of Airworthiness.
(e) Where paragraph D. of the table in paragraph 1.E., “Compliance,” of the service bulletin specified in paragraph (a) of this AD states: “Test the HSTA secondary brake when the HSTA reaches 24,000 hours (4C) (this is currently a scheduled maintenance task)'; this AD requires testing secondary brakes that have accumulated between 15,000 and 23,999 flight hours when the HSTA reaches 24,000 flight hours or within 500 flight hours after the effective date of this AD, whichever occurs later. For HSTAs that have accumulated between 24,000 and 29,999 flight hours, this AD requires testing the secondary brake within 500 flight hours after the effective date of this AD. All testing should be done in accordance with the service bulletin.
(f) For Model 757-300 series airplanes: Prior to the accumulation of 30,000 total flight hours, overhaul the primary brake and differential assembly of the HSTA in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0143, Revision 1, dated October 23, 2003. Repeat the overhaul thereafter at intervals not to exceed 30,000 flight hours.
(g) Overhauls of the primary brake and tests of the secondary brakes accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 757-27A0142, dated February 13, 2003; or Revision 1, dated April 10, 2003; and overhauls of the primary brake accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 757-27A0143, dated February 13, 2003; are considered acceptable for compliance with the overhaul of the primary brake only and tests of the secondary brakes specified in this AD.
(h) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office (ACO), FAA, is authorized to approve AMOCs for this AD.
(i) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 757-27A0142, Revision 2, dated October 23, 2003; or Boeing Alert Service Bulletin 757-27A0143, Revision 1, dated October 23, 2003; as applicable. This 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 may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
