Airworthiness Directive · Amendment 39-17763 · Air conditioning
The Boeing Company Airplanes
(1) This AD applies to The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category, as identified in Boeing Service Bulletin 737-21-1186, dated April 17, 2012.
(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/BE866B732F6CF31086257B9700692796?OpenDocument&Highlight=st01219se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by reports of chaffing, arcing, and burning damage to the control cabin overhead wiring and ducting with smoke and fire caused by metal clamps installed on certain hoses. This AD requires inspecting for the presence of metal clamps, replacing metal clamps installed on the hoses to the air conditioning temperature sensor, gasper air outlet, and diffuser on the left side of the control cabin with plastic tie straps, and inspecting for and repairing damaged wire bundles. We are issuing this AD to prevent damage to wire bundles, which could cause electrical arcing that could result in a fire or smoke in the control cabin of the airplane.
For airplanes identified in Groups 1 and 2 in Boeing Service Bulletin 737-21-1186, dated April 17, 2012: Within 60 months after the effective date of this AD, do the actions in (g)(1) and (g)(2) of this AD.
(1) Do a general visual inspection to determine if any metal clamp is installed on the hoses to the air conditioning temperature sensor, gasper air outlet, and diffuser on the left side of the control cabin at station (STA) 259.5, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-21-1186, dated April 17, 2012. If any metal clamp is found installed, before further flight, replace each metal clamp with a plastic tie strap, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-21-1186, dated April 17, 2012.
(2) Do a general visual inspection for damage to the adjacent wire bundles and repair any damaged wire bundles, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-21-1186, dated April 17, 2012. Do all applicable repairs before further flight.
For airplanes identified in Group 3 in Boeing Service Bulletin 737-21-1186, dated April 17, 2012: Within 60 months after the effective date of this AD, replace any metal clamp installed on the hoses to the air conditioning temperature sensor, gasper air outlet, and diffuser on the left side of the control cabin at STA 259.5, and inspect adjacent wire bundles and repair any damage, before further flight, using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
