Service difficulty report · Floorbeam · Boeing 737*

Difficulty date
March 17, 2022
Submitted
April 20, 2022
Operation
Air carrier
Aircraft
N472WN
Make and model
Boeing 737*
Aircraft serial
33831
Aircraft time
58,559 hours, 34,804 cycles
Part
Floorbeam
Condition
Corroded
Location
Fuselage
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 FLOOR BEAM UPPER SURFACE AT B.S. 986.5; R.B.L. 35 - R.B.L.45; W.L. 208.1. / [01] SRM 53-70-51-1A-1 ALLOWABLE DAMAGE 1 IS APPLICABLE TO THIS A/C;[27] FABRICATED; LOCATED AND DRILLED FLOOR BEAM REPAIR PARTS AT BS 986 ; FROM LBL 55 TO RBL 55 WL 208.1 ; [1] 2EA T-CHORD USING EXTRUSION BAC1505-101474 7050-T76511 LOT#1386011-1; [2] 2EA ANGLE USING FORMED ANGLE BAC1490-2811 7075-T6 CLAD LOT# 1482279-1; [3] 2EA ANGLE USING FORMED ANGLE BAC1490-2887 7075-T6 CLAD LOT# 1395413-1; [4] 2 EA STRAPS USING 7075-T6 .080' CLAD SHEET LOT# 1379745-2 (SPLICED -2;-3 AND -4 AT RBL 31.5) AND APPLIED CHEMICAL CONVERSION COATING ; IAW SRM 53-70-51-2R-4 REPAIR 4; REPAIR ALTERNATIVE 1 AND SRM 51-20-01.<BR><BR>OK TO PRIME PARTS.;[28] VERIFIED CORRECTIVE ACTION 27. <BR><BR>FABRICATION OF REPAIR PARTS ITEMS 1; 2; 3; 4. <BR><BR>OK TO PRIME PARTS.;[29] PRIMED FLOOR BEAM REPAIR PARTS AT BS 986 ; FROM LBL 55 TO RBL 55 WL 208.1 [-1; -2; -3; -4 ] AND STRUCTURE WITHIN THE REPAIR AREA IAW SRM 53-70-51-2R-4 REPAIR 4; REPAIR ALTERNATIVE 1 AND SOPM 20-41-02.;[30]