Service difficulty report · Floorbeam · Boeing 7377H4

Difficulty date
March 10, 2023
Submitted
April 18, 2023
Operation
Air carrier
Aircraft
N281WN
Make and model
Boeing 7377H4
Aircraft serial
36528
Aircraft time
51,516 hours, 31,045 cycles
Part
Floorbeam
Condition
Corroded
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

CORROSION ON LATERAL BEAM AT FWD CABIN BS270 LBL10 WL208.<[01] REMOVED 1 EA HILOK AT LBL 10 BS 270WL 208.1 IAW SRM 51-40-02;[02] REMOVED CORROSION ON LATEAL BEAM AT FWD CABIN BS 270 LBL 10 WL 208 IN 1.1'LX 0.8'W AREA IAW SRM 51-10-02;[03] VERIFIED CORRECTIVE ACTIONS 1 AND 2;[04] REQUESTED HFEC UT REMAINING THICHNESS ON THE BLENDED AREA AND OPEN HOLE;[05] ACCOMPLISHED HFEC SURFACE SCAN IAW 737 NDTM PART 6 CHAPTER 51-00-00 PROCEDURE 23. NO CRACKS NOTED.<BR><BR>ACCOMPLISHED HFEC OPEN HOLE INSPECTION IAW 737 NDTM PART 6 CHAPTER 51-00-00 PROCEDURE 16. NO CRACKS NOTED.<BR><BR>ACCOMPLISHED HFEC COUNTERSINK INSPECTION IAW 737 NDTM PART 6 CHAPTER 53-30-00 PROCEDURE 3. NO CRACKS NOTED.<BR><BR>ACCOMPLISHED UT THICKNESS MEASUREMENT IAW 737 NDTM PART 4 CHAPTER 51-00-00 PROCEDURE 2.<BR>MINIMUM REMAINING MATERIAL THICKNESS FOUND 0.077' ADJACENT TO 0.100'<BR><BR>EQUIPMENT USED: <BR>-NORTEC 600 ID: ATS2353 CAL DUE: 01/2024<BR>-EPOCH 600 ID: ATS843 CAL DUE: 06/2023;[06] AFTER REMOVED CORROSION ON LATEAL BEAM AT FWD CABIN BS 270 LBL 10 WL 208; EVALUATED DAMAGE ON REWORKED AREA ORIGINAL THICKNESS .100' MATERIAL REMOVED 0.023' REMAINING MATERIAL; 0.077' ALLOWABLE DAMAGE ONLY 10% OF MATERIAL LOSS; FOUND TO BE OU OF LIMIT IAW SRM 53-10-51-1A-1;[07] VERIFIED CORRECTIVE ACTION ITEM 6.;[08] FABRICATED REPAIR PARTS; [1] STRAP FROM MAT 7075-T6#0.063 LOT# 1498631-1 [2] 3(EA) TAPERED FILLERS FROM MAT 7075-T6#0.063 LOT# 1498631-1; LOCATED AND DRILLED ALL PARTS IAW EA NO: 23-153-00883;

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