Service difficulty report · Bulkhead · Boeing 7377H4

Difficulty date
July 15, 2023
Submitted
July 19, 2023
Operation
Air carrier
Aircraft
N924WN
Make and model
Boeing 7377H4
Aircraft serial
36628
Aircraft time
49,397 hours, 29,879 cycles
Part
Bulkhead
Part number
UNKNOWN
Condition
Cracked
Location
Zn 100 Fus Lower
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

L/H 663.75 LOWER BULKHEAD CRACKED. CRACKS STARTS APPROXIMATELY LBL 54.21 AND TRAVELS TO LBL 40.00. CRACK MEASURES AT 15 1/2 INCHES BEFORE IT GOES BEHIND THE HYDRAULIC MODULE BRACKET. ONCE CRACK GOES BEHIND HYDRAULIC MODULE BRACKET IT CAN NO LONGER BE MEASURED DUE TO THE FACT THAT IT IS HIDDEN. ALLOWABLE DAMAGE IS NO MORE THAN 16 INCHES PER SRM 57-10-10-1A-2. FIRST 7 INCHES OF CRACK IS ALL THE WAY THROUGH FIBERGLASS MATERIAL.<[01] CW;[02] CW;[03] REMOVED HYDRAULIC SYSTEM A AND B PRESSURE MODULE PER AMM 29-11-71.;[04] REMOVED A AND B PRESSURE MODULE MOUNTING BRACKET PER AMM 29-11-71. REMOVED NGS RAM AIR VALVE EXHAUST DUCT AND PANEL AMM 47-32-05.;[05] UPON REMOVAL OF PRESSURE MODULE MOUNTING BRACKET FOUND THAT CRACK EXTENDS AN ADDITIONAL 3.0 INCHES.;[06] REINSTALLED LH WHEEL WELL PRESSURE MODUEL MOUNTING BRACKET REF 737 SRM 51-40-02;[07] INSTALLED A SYS HYDRAULIC PRESSURE MODULE IAW AMM 29-11-71;[08] INSTALLED NGS RAM AIR VALVE EXHAUST DUCT AND PANEL IAW AMM 47-32-05.;[09] INSTALLED A SYS HYDRAULIC PRESSURE MODULE IAW AMM 29-11-71. ENG SIDE PRESSURE MODULE REQUIRES LEAK CHECK.;[10] A SYS HYDRAULIC PRESSURE MODULE LEAK CHECK COMPLIED WITH ON TTG8Q00M8SV4;[11] REPAIRED LH 663.75 LOWER BULKHEAD CRACK PER EA 23-157-02209 REF WO# TTG8Q00M8KD2

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