777 MAINTENANCE PLANNING DATA 

777 

MAINTENANCE PLANNING DATA (MPD) DOCUMENT 

SECTION 9 

AIRWORTHINESS LIMITATIONS (AWLs) AND 

RTIFICATION MAINTENANCE REQUIREMENTS (CMRs) 

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OCTOBER 2014 

COMPILED AND PUBLISHED BY: 

MAINTENANCE PROGRAMS ENGINEERING 

COMMERCIAL AVIATION SERVICES 

BOEING COMMERCIAL AIRPLANE GROUP 

SEA TILE, WASHINGTON 

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777 MAINTENANCE PLANNING DATA 

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TABLE OF CONTENTS 

9.0-5 

S 9.0-20 

9.0-21 

ATIONS- STRUCTURAL INSPECTIONS ..................................................................................................................................... 9.0-22 

ATIONS- STRUCTURAL SAFE-LIFE LIMITS 9.0-108 

ATIONS- SYSTEMS ...................... ............................................................................................................................................ .. 9.0-114 

TION PREVENTION 8 

EED SYSTEM 9.0-136 

TION SYSTEM 9.0-138 

Y FORWARD STRUT DRAIN LINE 9.0-143 

UST REVERSER THERMAL PROTECTION SYSTEM .... ........................................................................................................... 9.0-145 

NANCE REQUIREMENTS (CMRs) ............................................................................................................................................ 9.0-148 

NANCE REQUIREMENTS TASKS 9.0-154 

OLLABLE HIGH THRUST FAILURE CONDITIONS 9.0-157 

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777 MAINTENANCE PLANNING DATA 

ORWARD STRUT DRAIN LINE 

AA approved program of Forward Strut Drain Line Scheduled inspections. Operators should incorporate these inspections into 

s to meet Title 14 CFR § 25.901(b)(2) for those strut drains that are identified as applicable. 

ve temperatures combined with draining fluids have contributed to clogging of the forward strut drain line. Hydraulic fluid has 

le leakage zone, the left systems electrical bay, in the strut forward dry bay, and forward engine mount. The titanium engine 

rogen embrittlement when exposed to hydraulic fluid. The addition of drain line insulation (see Service Bulletin 777-71-0055) 

xperienced by the drain lines minimizing the clogging of the drain such that periodic inspection will prevent clogging and pooled 

nspections. 

ne functional check AWL is mandatory maintenance to ensure safe operation of the strut drainage system as required by 

. The Forward Strut Drain Line functional check verifies the drain will be functional until the next scheduled inspection. 

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777 MAINTENANCE PLANNING DATA 

INTERVAL APPLICABILITY DESCRIPTION 

2,000 FC/ 777 Airplanes Forward Strut Drain Line 

1,500 DY Line Number Concern: Potential for hydraulic fluid clogging the Forward Strut drain line causing subsequent dogging of NOTE 1118 and on the Left Systems Disconnect. Strut Forward Lower Spar Inlet and Forward Fire Seal Pan Inlet which could 

wi1h PW4000 result in pooled flammable fluid in a flammable leakage zone which poses a potential fire hazard. engines Hydraulic Fluid can also back up into the strut forward dry bay and cause hydrogen embrittlement of the 

777 Airplanes 

forward engine mount fittings that could cause cracks that lead to the loss of load carrying capability for the 

forward engine mount. Line Numbers 

1 through 1117 Perform a Forward Strut Drain Line Functional Check (refer to Boeing AMM 54-55-01) to ensure the drain 

with PW4000 has sufficient flow. 

engines 1. Apply 381oz (11.27 I) to 387 oz (1 1.44 I) of water into the strut disconnect box over a 45 to 90 second that have period. incorporated 

Service Bulletin 2. Verify a minimum of 354 oz (10.471) is collected within two minutes after pouring water is complete. 

777-71-0055 3. If the flow requirement is not met then additional checks are required to verify the following: 

a. Verify that the three drain lines that connect to the Forward Strut drain line are cleared of 

blockage from the drain outlet to the following inlets: Left Systems Disconnect, Strut Forward 

Lower Spar Inlet and Forward Fire Seal Pan Inlet. 

b. Verify that there is no evidence of hydraulic fluid contamination in the strut forward dry bay. 

NOTE: Access is through 432AR or 442AR. The Boeing Service Bulletin 777-54-0028 contains 

accepted practices for inspection, cleaning and refinishing of the strut forward dry bay. 

Interval Note: Whichever comes first. 

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