Service difficulty report · Flange · Boeing 7377H4

Difficulty date
March 23, 2022
Submitted
May 3, 2022
Operation
Air carrier
Aircraft
N424WN
Make and model
Boeing 7377H4
Aircraft serial
29828
Aircraft time
66,349 hours, 39,132 cycles
Part
Flange
Condition
Cracked
Location
L1 Door
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

FWD CABIN WET AREA L/H CEILING FRAME FLANGE CRACKED AT STA 312 ABOVE L-1 DOOR CUTOUT MKD DOT / REMOVED EXISTING FASTENERS FOR ACCESS TO REPAIR IN IAW SRM 51-40-02-0G-0; CUT OUT THE DAMAGED AREA OF UPPER CHORD FRAME AT FWD CABIN WET AT STA 312 L/H SIDE ABOVE L-1 DOOR IN IAW SRM 53-10-07-2R-1 FIG 202 DETAIL A SHEET 1 AND 51-10-02-0G-0;[CHECKED SURFACE ROUGHNESS ON CUT OUT AREA FOUND SMOOTHER THEN 125 MICROINCHES IN IAW SRM 51-20-13-0G-0 CHECKED SURFACE ROUGHNESS ON CUT OUT AREA FOUND SMOOTHER THEN 125 MICROINCHES IN IAW SRM 51-20-13-0G-0 (TOOL USED B/C 172329). NO OTHER DEFECTS NOTED. SRM 737-700 53-10-07-2R-1 PAR 4.F.;PERFORMED HFEC AT CUT OUT IAW NDTM PART 6; 51-00-00 PROCEDURE 23. NO CRACKS;FABRICATED ANGLE REPAIR AT FWD CABIN WET AREA L/H CEILING FRAME FLANGE AT STA 312 MATERIAL USED 7075-0 0.063' DIMENSION 4'X 6 1/2' IN IAW SRM 53-10-07-2R-1. REFER TO TABLE 201/ REPAIR 1 AND FIG 203;[09] VERIFIED STEP 8 . PERFORMED HEAT TREATMENT TEST ON ANGLE FOUND BETWEEN OF PARAMETERS IN IAW SRM 53-10-07-2R-1 AND BAC 5602; OP 84; LOCATED AND DRILLED REPAIR ANGLE IN IAW SRM 51-40-05-0G-0;[14] VERIFIED STEP 13;TREATED WITH ALODINE AND PRIME REPAIR ANGLE IN IAW SRM 51-20-01-0G-0 AND 51-21-72-370-804 INSTALLED REPAIR ANGLE AT FWD CABIN WET AREA L/H CEILING FRAME FLANGE AT STA 312 ABOVE L-1 DOOR CUTOUT IN IAW SRM 53-10-07-2R-1 AND FIG 203 SHEET 1 ACCOMPLISHED PERMANENT REPAIR OF CRACK AT UPPER FRAME STA 312 BETWEEN S-5L AND S-6L PER REF B737 SRM 53-10-07-2R-1

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