Airworthiness Directive · Amendment 39-18304 · Air conditioning
The Boeing Company Airplanes
This AD applies to The Boeing Company airplanes, certificated in any category, as identified in paragraphs (c)(1) and (c)(2) of this AD.
(1) Model 737-100, -200, -200C, -300,-400, and -500 series airplanes, as identified in Boeing Special Attention Service Bulletin 737-21-1164, Revision 2, dated August 23, 2013.
(2) Model 737-600, -700, -700C, -800,-900, and -900ER series airplanes, as identified in Boeing Special Attention Service Bulletin 737-21-1165, Revision 3, dated July 16, 2014.
We are superseding Airworthiness Directive (AD) 2015-16-01 for certain The Boeing Company Model airplanes. AD 2015-16-01 required incorporating design changes to improve the reliability of the cabin altitude warning system by installing a redundant cabin altitude pressure switch, replacing the aural warning module (AWM) with a new or reworked AWM, and changing certain wire bundles or connecting certain previously capped and stowed wires as necessary. For certain airplanes, AD 2015-16-01 also required prior or concurrent incorporation of related design changes by modifying the instrument panels, installing light assemblies, modifying the wire bundles, and installing a new circuit breaker, as necessary. This AD retains all actions required by AD 2015-16-01. This AD was prompted by the discovery of a typographical error in AD 2015-16-01 that referred to a nonexistent paragraph. We are issuing this AD to prevent the loss of cabin altitude warning, which could delay flightcrew recognition of a lack of cabin pressurization, and could result in incapacitation of the flightcrew due to hypoxia (a lack of oxygen in the body), and consequent loss of control of the airplane.
This paragraph restates the actions required by paragraph (g) of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015), with removal of the limitation to use certain service information from paragraph (g)(2) of this AD. Within 72 months after November 7, 2012 (the effective date of AD 2012-19-11, Amendment 39-17206 (77 FR 60296, October 3, 2012)), install a redundant cabin altitude pressure switch, replace the aural warning module (AWM) with a new or reworked AWM, and change certain wire bundles or connect certain capped and stowed wires, as applicable, in accordance with the Accomplishment Instructions of the applicable service information in paragraphs (g)(1) and (g)(2) of this AD; except as provided by paragraph (k)(1) of this AD.
(1) Boeing Special Attention Service Bulletin 737-21-1164, Revision 1, dated May 17, 2012; or Boeing Special Attention Service Bulletin 737-21-1164, Revision 2, dated August 23, 2013 (for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes). As of September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), use Boeing Special Attention Service Bulletin 737-21-1164, Revision 2, dated August 23, 2013, for the actions specified in paragraph (g) of this AD.
(2) Boeing Special Attention Service Bulletin 737-21-1165, Revision 1, dated July 16, 2010, as revised by Boeing Special Attention Service Bulletin 737-21-1165, Revision 2, dated April 30, 2012; or Boeing Special Attention Service Bulletin 737-21-1165, Revision 3, dated July 16, 2014 (for Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes).
This paragraph restates the concurrent actions required by paragraph (h) of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015), with no changes. For airplanes identified in Boeing Alert Service Bulletin 737-31A1325, dated January 11, 2010 (for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes); and Boeing Alert Service Bulletin 737-31A1332, Revision 3, dated March 28, 2012 (for Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes); except as provided by paragraph (i) of this AD: Before or concurrently with accomplishment of the actions specified in paragraph (g) of this AD, as applicable, modify the instrument panels, install light assemblies, modify the wire bundles, and install a new circuit breaker, in accordance with the Accomplishment Instructions of the applicable service information in paragraphs (h)(1) and (h)(2) of this AD; except as provided by paragraph (k)(2) of this AD.
(1) The service information for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes as identified in paragraphs (h)(1)(i), (h)(1)(ii), and (h)(1)(iii), of this AD. As of September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), use Boeing Alert Service Bulletin 737-31A1325, Revision 2, dated June 5, 2014 (for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes), for the actions specified in paragraph (h) of this AD.
(i) Boeing Alert Service Bulletin 737-31A1325, dated January 11, 2010.
(ii) Boeing Alert Service Bulletin 737-31A1325, Revision 1, dated July 5, 2012.
(iii) Boeing Alert Service Bulletin 737-31A1325, Revision 2, dated June 5, 2014.
(2) Boeing Alert Service Bulletin 737-31A1332, Revision 3, dated March 28, 2012; or Boeing Alert Service Bulletin 737-31A1332, Revision 4, dated October 31, 2013 (for Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes). As of September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), use Boeing Alert Service Bulletin 737-31A1332, Revision 4, dated October 31, 2013 (for Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes), for the actions specified in paragraph (h) of this AD.
This paragraph restates the concurrent actions required by paragraph (i) of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015), with no changes. For airplanes having variable numbers YA001 through YA008 inclusive, YA251, YA501 through YA508 inclusive, and YC321 through YC325 inclusive: Before or concurrently with accomplishment of the actions specified in paragraph (g) of this AD, or within 18 months after September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), whichever occurs later, modify the instrument panels, install light assemblies, modify the wire bundles, and install a new circuit breaker, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-31A1332, Revision 4, dated October 31, 2013.
(1) This paragraph restates the credit for previous actions stated in paragraph (i) of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015), with corrected paragraph reference.
(i) This paragraph provides credit for the actions required by paragraph (g) of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015), if those actions were performed before November 7, 2012 (the effective date of AD 2012-19-11, Amendment 39-17206 (77 FR 60296, October 3, 2012)), using Boeing Special Attention Service Bulletin 737-21-1165, Revision 1, dated July 16, 2010, which was incorporated by reference in AD 2012-19-11.
(ii) For airplanes identified in Boeing Alert Service Bulletin 737-31A1332, Revision 1, dated June 24, 2010; except airplanes having variable numbers YA001 through YA019 inclusive, YA201 through YA203 inclusive, YA231 through YA242 inclusive, YA251, YA252, YA271, YA272, YA301, YA302, YA311, YA312, YA501 through YA508 inclusive, YA541, YA701, YA702, YC001 through YC007 inclusive, YC051, YC052, YC101, YC102, YC111, YC121, YC301, YC302, YC321 through YC330 inclusive, YC381, YC401 through YC403 inclusive, YC501, YC502, and YE001 through YE003 inclusive: This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), using Boeing Alert Service Bulletin 737-31A1332, Revision 1, dated June 24, 2010, which was incorporated by reference in AD 2012-19-11, Amendment 39-17206 (77 FR 60296, October 3, 2012).
(iii) For airplanes identified in Boeing Alert Service Bulletin 737-31A1332, Revision 2, dated August 18, 2011; except airplanes identified in paragraph (j)(1)(iv) of this AD and airplanes having variable numbers YA001 through YA019 inclusive, YA201 through YA203 inclusive, YA231through YA242 inclusive, YA251, YA252, YA271, YA272, YA301, YA302, YA311, YA312, YA501 through YA508 inclusive, YA541, YA701, YA702, YC001 through YC007 inclusive, YC051, YC052, YC101, YC102, YC111, YC121, YC301, YC302, YC321 through YC330 inclusive, YC381, YC401 through YC403 inclusive, YC501, YC502, and YE001 through YE003 inclusive: This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), using Boeing Alert Service Bulletin 737-31A1332, Revision 2, dated August 18, 2011, which was incorporated by reference in AD 2012-19-11, Amendment 39-17206 (77 FR 60296, October 3, 2012).
(iv) For Group 21, Configuration 2 airplanes identified in Boeing Alert Service Bulletin 737-31A1332, Revision 3, dated March 28, 2012: This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), using Boeing Alert Service Bulletin 737-31A1332, Revision 2, dated August 18, 2011, which was incorporated by reference in AD 2012-19-11, Amendment 39-17206 (77 FR 60296, October 3, 2012); and provided that the actions specified in Boeing Service Bulletin 737-21-1171, dated February 12, 2009 (which is not incorporated by reference in this AD), were accomplished prior to or concurrently with the actions specified in Boeing Alert Service Bulletin 737-31A1332, Revision 2, dated August 18, 2011.
(2) This paragraph provides credit for the actions specified in paragraph (h) of this AD, if those actions were performed before September 15, 2015 (the effective date of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015)), using the service information identified in paragraph (j)(2)(i) or (j)(2)(ii) of this AD.
(i) Boeing Alert Service Bulletin 737-31A1325, dated January 11, 2010, which was incorporated by reference in AD 2012-19-11, Amendment 39-17206 (77 FR 60296, October 3, 2012).
(ii) Boeing Alert Service Bulletin 737-31A1325, Revision 1, dated July 5, 2012, which is not incorporated by reference in this AD.
This paragraph restates the actions required by paragraph (k) of AD 2015-16-01, Amendment 39-18226 (80 FR 48013, August 11, 2015), with no changes.
(1) Where Boeing Special Attention Service Bulletin 737-21-1164, Revision 2, dated August 23, 2013, specifies to contact Boeing for instructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
(2) Where Boeing Alert Service Bulletin 737-31A1325, Revision 2, dated June 5, 2014, specifies to contact Boeing for instructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
