Airworthiness Directive · Amendment 39-17163 · Flight controls
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 757 airplanes. This AD was prompted by a report of extensive corrosion of the ballscrew of the drive mechanism of the horizontal stabilizer trim actuator. This AD requires repetitive detailed inspections for discrepancies of the horizontal stabilizer ballscrew assembly; repetitive lubrication of the horizontal stabilizer trim control system; repetitive measurements for discrepancies of the ballscrew to ballnut freeplay; and corrective actions, if necessary. We are issuing this AD to prevent undetected failure of the primary and secondary load paths for the ballscrew in the horizontal stabilizer, which could lead to loss of control of the horizontal stabilizer and consequent loss of control of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For Group 1, Configuration 1 airplanes identified in Boeing Alert Service Bulletin 757-27A0144 (for Model 757-200, -200CB, and 200PF series airplanes) or 757-27A0145 (for Model 757-300 series airplanes), both Revision 1, both dated January 20, 2010, that have accumulated 15,000 total flight hours or fewer as of the effective date of this AD: Do the actions required by paragraphs (g)(1), (g)(2), and (g)(3) of this AD, at the times specified in those paragraphs, and in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0144 (for Model 757-200, -200CB, and -200PF series airplanes) or 757-27A0145 (for Model 757-300 series airplanes), both Revision 1, both dated January 20, 2010.
(1) Within 3,500 flight hours or 2 years after the effective date of this AD, whichever occurs first: Do a detailed inspection for discrepancies of the horizontal stabilizer ballscrew assembly. Repeat the inspection thereafter at intervals not to exceed 3,500 flight hours or 2 years, whichever occurs first.
(2) Within 2,000 flight hours or 1 year after the effective date of this AD, whichever occurs first: Lubricate the horizontal stabilizer trim control system. Repeat the lubrication thereafter at intervals not to exceed 2,000 flight hours or 1 year, whichever occurs first.
(3) Do the stabilizer ballscrew to ballnut freeplay check for discrepancies at the later of the times specified in paragraphs (g)(3)(i) and (g)(3)(ii) of this AD. Repeat the freeplay check thereafter at intervals not to exceed 18,000 flight hours or 5 years, whichever occurs first.
(i) Before the accumulation of 15,000 total flight hours.
(ii) Within 18 months after the effective date of this AD.
For Group 1, Configuration 2 airplanes identified in Boeing Alert Service Bulletin 757-27A0144 (for Model 757-200, -200CB, and 200PF series airplanes) or 757-27A0145 (for Model 757-300 series airplanes), both Revision 1, both dated January 20, 2010, that have accumulated more than 15,000 total flight hours as of the effective date of this AD: Do the actions required by paragraphs (h)(1), (h)(2), and (h)(3) of this AD, at the times specified in those paragraphs, and in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0144 (for Model 757-200, -200CB, and 200PF series airplanes) or 757-27A0145 (for Model 757-300 series airplanes), both Revision 1, both dated January 20, 2010.
(1) Within 3,500 flight hours or 18 months after the effective date of this AD, whichever occurs first: Do a detailed inspection for discrepancies of the horizontal stabilizer ballscrew assembly. Repeat the inspection thereafter at intervals not to exceed 3,500 flight hours or 2 years, whichever occurs first.
(2) Within 2,000 flight hours or 1 year after the effective date of this AD, whichever occurs first: Lubricate the horizontal stabilizer trim control system. Repeat the lubrication thereafter at intervals not to exceed 2,000 flight hours or 1 year, whichever occurs first.
(3) Do the stabilizer ballscrew to ballnut freeplay check for discrepancies within 18 months after the effective date of this AD. Repeat the freeplay check thereafter at intervals not to exceed 18,000 flight hours or 5 years, whichever occurs first.
For Group 1, Configuration 3 airplanes identified in Boeing Alert Service Bulletin 757-27A0144 (for Model 757-200, -200CB, and 200PF series airplanes) or 757-27A0145 (for Model 757-300 series airplanes), both Revision 1, both dated January 20, 2010: Do the actions required by paragraphs (i)(1), (i)(2), and (i)(3) of this AD, at the time specified in those paragraphs, and in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0144 (for Model 757-200, -200CB, and -200PF series airplanes) or 757-27A0145 (for Model 757-300 series airplanes), both Revision 1, both dated January 20, 2010.
(1) Within 3,500 flight hours or 2 years after the effective date of this AD, whichever occurs first: Do a detailed inspection for discrepancies of the stabilizer ballscrew assembly. Repeat the inspection thereafter at intervals not to exceed 3,500 flight hours or 2 years, whichever occurs first.
(2) Within 2,000 flight hours or 1 year after the effective date of this AD, whichever occurs first: Lubricate the horizontal stabilizer trim control system. Repeat the lubrication thereafter at intervals not to exceed 2,000 flight hours or 1 year, whichever occurs first.
(3) Do the stabilizer ballscrew to ballnut freeplay check for discrepancies at the later of the times specified in paragraphs (i)(3)(i) and (i)(3)(ii) of this AD. Repeat the freeplay check thereafter at intervals not to exceed 18,000 flight hours or 5 years, whichever occurs first.
(i) Within 15,000 flight hours after accomplishing an overhaul specified in Boeing Alert Service Bulletin 757-27A0142, Revision 2, dated October 23, 2003 (for Model 757-200, -200CB, and -200PF series airplanes); or Boeing Alert Service Bulletin 757-27A0143, Revision 1, dated October 23, 2003 (for Model 757-300 series airplanes).
(ii) Within 18 months after the effective date of this AD.
If any discrepancy is found during any action required by paragraph (g), (h), or (i) of this AD: Before further flight, do the replacement specified in paragraph (j)(1) or (j)(2) of this AD, in accordance with Subject 27-41-10, “Stabilizer Trim Ballscrew Freeplay,” of Chapter 27, “Flight Controls,” of the Boeing 757 Airplane Maintenance Manual (AMM), Revision 101, dated May 20, 2011; except as provided by paragraph (k) of this AD.
(1) Replace the HSTA with a new or overhauled HSTA.
(2) Replace the HSTA with a HSTA that is not new or overhauled on which a detailed inspection, freeplay measurement, and lubrication of that actuator are performed in accordance with paragraph (g), (h), or (i) of this AD, as applicable, and no discrepancies are found during the inspection and freeplay measurement.
No action is required if a freeplay measurement greater than or equal to 0.001 inch but less than 0.016 inch, is found and the measurement is verified to have been performed correctly. This AD requires HSTA replacement, as specified in paragraph (j) of this AD, if a freeplay measurement is less than 0.001 inch, or greater than or equal to 0.016 inch.
Note 1 to paragraph (k) of this AD: Additional guidance for the verification of the measurement can be found in Subject 27-41-10, “Stabilizer Trim Ballscrew Freeplay,” of Chapter 27, “Flight Controls,” of the Boeing 757 AMM, Revision 101, dated May 20, 2011.
Any HSTA overhauled before the effective date of this AD, or within the compliance time specified in paragraph (g), (h), or (i) of this AD, as applicable—that included removal of the HSTA from the airplane and overhaul of the stabilizer ballscrew, as specified in Linear Motion Component Maintenance Manual with Illustrated Parts List, Ball Screw Assembly, Linear Motion Part No. 7820700, Boeing Part No. (S251N201-1), 27-41-10, Revision 3, dated October 2, 2007—meets the intent of one detailed inspection, one freeplay inspection, and one lubrication of the HSTA, as specified in paragraphs (g), (h), and (i) of this AD; and therefore, is considered acceptable for compliance with the initial accomplishment of the actions specified in paragraph (g), (h), or (i) of this AD, as applicable, and the repetitive interval for those actions may be determined from the performance date of that overhaul.
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
