14910-13-P]
IO-NM-035-AD} 

# IDLi1D IDocket No. FAA-10IO-++++j Directorate Identifier 2 Ainvortbiness Directives; The Boeing Company Model 747-400 and 747-400D Series m RIN 2120-AA64 Federal Aviation Administration DEPARTMENT OF TRANSPORT AnON 14 CFR Part 39

NG SYMBOL

IAlSiS'G lIT''''' SYMOOl 

# 'I &6/ID

OUTING SYMBOL r main equipment centerl(MEC); and adding areinfOrCig fiberglass overcoat to the top surface ofthe MEC drip shield, including an inspecti~n

# forcracking and holes inthe MEC drip shield, and corrective actions ifnecessary.

# 15proposed AD also provides an option to install anMEC drip shield drain system, wlich, ifaccomplished, would extend the comPlianceltime for adding the reinforcini fiferglass overcoat to the top 

# I .mv .• t.stsl(; surface ofthe MEC drip shield. This proposed AD resulls from areport indicating that n operator experienced amulti-power system loss in-fliJ of#1, #2, and #3 alternating 

# I current 

### (AC)electrical power systems located inthe

### MC, We areproposing this AD t prevent water penetra~ion into the MEC, which cOUIJri.ult in the loss of flight critical 

# '":="''' systems. DATES: We must receive comments on this proposed AD by [INSERT DATE 45 UT!l"GSYMOOl DAYS AFTER DATJ OF PUBLICATION IN THE rJDERAL REGISTER]. Airplanes AGENCY: Federal Aviation Administration (FAA), DO ACTION: Notice ofproposed rulemaking (NPRM). SUMMARY: We proPloseto adopt anew airworthineks ~irective (AD) for certain Mod;5'1 /0 I 

### IT Olll1NQSYMBOl 747-400 and 747-400D series airplanes. This proposed would require installing •
_ b
~ aluminum gutter reinforcing brackets to the forward and aft drip shield gutters ofthe(4910-I3-P)

DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14CFR Part 39 IDoeke! No. FAA-2010-++++; Directorate Identifier 2010-NM-035-AD) RlN 2120-.'1..'1.64 

### 31HO

OUTING SYMllO<. ROUTING SYMBOl Airplanes Ainvorthiness Directives; The Boeing Company Model 747-400 and 747-4000 Series AGENCY: Federal Aviation Administration (FAA),

# DOT ACTION: Notice ofproposed rulemaking (NPRM). 

# I SUMMARY: We propose to adopt a new airworthiness lirective (AD) for certain Mod 747-400 and 747-400D series airplanes. This proposed ,ADwould require installing aluminum gutter reinforcing brackets to the forward and

## J1ft drip shield gutters ofthe 

## ,'Ei-AEE, main equipment center (MEC); and adding areinforcing fiberglass overcoat to tbe top Nfl1..llSISIG surface ofthe MEC drip shield, including aninspection fJr cracking andholes inthe A~G~ MEC drip shield, and corrective actions ifnecessary. The optional installation ofa MEC 

# A~ 

# t l o~~'~~oc drip shield drain system would extend the compliance til. efor adding the reinforcing fiberglass overcoat to th top s,urfaceofthe MEC drip Jhield. This proposed AD results from arep0l1 ofan opertor experiencing a mUlti-POWe~ s stem loss in-flight of#], 2, and 3 alternating currenJ (AC) electrical power systemJ 

### 1 cated inthe MEC. We are



# I I NlT\AlS/SIG proposing this AD toprevent water penetration into the MEC, which could result in the loss offlight critical systems. DATES: We mllst receive comments on this proposed AID by [INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN THE F~Dr.Rt-L REGISTER]. ADDRESSES: You may send comments by any ofthe following methods:
• Federal eRulemaking Portal: Go to http://www.lgulations.gov. Follow the 

## '" instructions for submitting comments. 

## '"DEPARTMENT OF TRANSPORT AnON

Federal Aviation Administration ONClJRRE"CES ovn"G SYMBOL 14 CFR Part 39 ("DocketNo. FAA-10lO-++++; Directorate Identificii 2 lO-NM-035-AD} 

### ft':J rn-j

### 14 INITlALS/Slt; 

# :DIL R1N 2120-AA64 'ATE h B ' CdS· ROlJTlNG SYI-l60l Airworthiness Directives; T e oemg ompany Mo el

### 747AOO and 747-400D enes fhJfA-I'1;;c, ril~ Airplanes NlTlAL.SISIG 

## S_f"-

OlfT1NG SY'1BOL

OunNG '1BOl DATE 

### I1M,h 12/010
,':L,H:jELl NITI {,\\-

ROUTING SYMBO~ 

## ,~ D<JTINGS~"'50L NITIAi.$!SIC; 

## '" O\fl1NG sYM80lNITlAl.S{SIG 

## '" DATE EC, which could result IIIthe AGENCY: Federal Aviation Administration (FAA), 001. ACTION: Notice ofprJposed rulemaking (NPRlv1). SUMMARY: We propJse to adopt a new airworthiness 1irective (AD) for certain Mod 747-400 and 747-400D 

### leri~s airplanes. This proposed

# Ab would require installing aluminum gutter reinfOr~ing brackets to the fOf\vard anCilft drip shield": gut~ers ofthe main equipment center 1MEC); and addmg areinforcl+ fberglaSS overcoat to tbe top surface ofthe 

### :MEC drip'shield, including an mspection [.,rcracking and holes in the ATE MEC drip shield, and cdrrective actions ifnecessary ~e optIOnal installation of aMEC I drip shield drain system would extend the compliance ~i efor adding the reinforcing I fiberglass overcoat to the top surface ofthe MEC drip Shiild. This proposed AD results ITom areport ofan operltor experiencing amOlti-powJr rstem loss in-flight of#I, 2, and 3 alternating curren~ (AC) electrical power systemJ I cated inthe MEC. We are
, h' AD I ' , th I proposmg t IS to prevent water penetratIOn mto e loss of flIght cntlcal syslems. DATES: We must recei~e comments on this proposed

# 11by [INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION INTHE FEJ~RAL REGISTER]. ADDRESSES: You mal send comments by any ofthJ follo:ing methods
• Federal eRule~aking Portal. Go to htt 

# ://wwt.Je ulations. ov Follow the
, '" b I InstructIOns lor su mlttmg comments.