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## /lJ';, -lilk Airworthiness Directives; McDonnell Douglas Corporation Model MD-90-30 Airplane AGENCY: Federal Aviation Administration (FAA), Department ofTransportation 

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# O~t/ [Docket No. FAA-2010-++++; Directorate Identifier 2010-NM-082-AD] 14CFR Part 39 DEPARTMENT OF TRANSPORT ATlON Federal Aviation Administration

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### (DOT). ACTION: Notice ofproposed rnlemaking (NPRM). SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Model MD·90-30 airplanes. The existing AD,currently requires modifying the auxiliary hydraulic power system (including doing all applicable related investigative and corrective actions). This proposed AD would require these same actions, using the corrected service information. This proposed AD results from fuel system reviews conducted by

### the manufacturer, aswell asreports ofelectrically shorted WUTING SYMBOL

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wires inthe right wheel well and evidence ofarcing onthe auxiliary hydraulic pump power cables, which arerouted within thetire burst area. We are proposing this AD to prevent electrically shorted wires orarcing atthe auxiliary hydraulic pump power cables, INI'rtALS'SIG 

### which could result inafire inthe wheel well. We are also proposing this AD to reduce thepotential ofanignition source adjacenttothe fuel tanks, which, in combination with flammable fuel vapors, could result inafuel tank explosion and consequent loss ofthe airplane. DATES: We must receive comments onthisproposed AD by [INSERT DATE 45 DAYS AFTER DATE OFPUBLICATION INTHE FEDERAL REGISTER]. ADDRESSES: You may send comments by any ofthe following methods:

• Federal eRulemaking Portal: Goto http://www.regulations.gov. Follow the AU

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DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14CFR Part 39 [Docket No. FAA-2010-++++; Directorate Identifier 2010-NM-082-ADI R1N 2120-AA64 Airworthiness Directives; McDonnell Douglas Corporation Model MD-90-30 Airplanes AGENCY: Federal Aviation Administration (FAA), Department ofTransportation (DOT). ACTION: Notice ofproposed rulemaking (NPRM). SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Model MD-90-30 airplanes. The existing AD currently requires modifying the auxiliary hydraulic power system (including doing all applicable related investigative and corrective actions). This proposed AD would require these same actions, using the corrected service information. This proposed AD results from fuel system reviews conducted by the manufacturer, as weU as reports ofelectrically shorted wires inthe right wheel well and evidence of arcing on the auxiliary hydraulic pump power cables, which are routed within the tire burst area. We are proposing this AD to prevent electrically shorted wires or arcing atthe auxiliary hydraulic pump power cables, which could result in a fire in the wheel welL We are also proposing this AD to reduce the porential ofan ignition source adjacent to the fuel tanks, which, in combination with flammable fuel vapors, could result ina fuel tank explosion and consequent loss of the airplane. DATES: We must receive comments on this proposed AD by [INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. ADDRESSES: You may send comments by any ofthe follo\o\'ingmethods:

• Federal eRulemaking Portal: Go to http://www.regulations.2ov. Follow the ~0lIT'''(>S7l\Cll ,,,rrw.s.sTTuI<E 

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FAA Form 1360-14.1 (6-89) OFFICIAL FILE COPY