Service difficulty report · Floorbeam · Boeing 7377H4

Difficulty date
May 3, 2022
Submitted
June 9, 2022
Operation
Air carrier
Aircraft
N477WN
Make and model
Boeing 7377H4
Aircraft serial
33988
Aircraft time
60,414 hours, 35,826 cycles
Part
Floorbeam
Part number
147A55068
Condition
Corroded
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 FLOORBEAM UPPER SURFACE AT STA 986.5; WL 208; BUTT LINES: RBL 41.5-45; RBL 35; RBL 21; LBL 30; LBL 35; LBL 42; LBL 44. / ALL FOUND TO BE OUT OF LIMITS PER SRM 53-70-51-1A-1 CUT AND REMOVED UPPER FLANGE OF BS 986.5 FLOOR BEAM PER SRM 53-70-51-2R-4;[11] VERIFIED CORRECTIVE ACTION #10;[12] REQUIRED DVI PER SRM 53-70-51-2R-4 STEP 4.C.1;[13] VERIFIED;[14] REQUIRED NDI PER SRM 53--70-51-2R-4 STEP 4.C(2-4) AND STEP 4.E.(1) FLAP PEENED THE CUT EDGE WITH 200%; IAW SRM 53-70-51-2R-4 STEP 4.D PER S.O.P.M. 20-10-03;2EA. -3 ANGLES FROM BAC1490-2887 7075T62 CLAD; LOT# 1395413-1<BR>2EA. -4 STRAPS FROM .080' 7075T6 CLAD; LOT# 1379745-2;[31] APPLIED CHEMICAL CONVERSION COATING TO CUT EDGE OF BS 986.5 FLOORBEAM PER SRM 53-70-51-2R-4.;[32] VERIFIED CORRECTIVE ACTIONS STEP 30;31.;[33] REQUIRED DVI OF THE CUT AND TRIM AREA ON INTERCOSTAL AT RBL38 AND RBL 7 IAW SRM 53-70-51-2R-4 STEP 4.F(3-4);[34] CERTIFY;[35] RECEIVED 4EA CORNER FITTINGS (CUSTOMER RO 866686-SWA) LOCATED; DRILLED; TRIMMED TO SIZE AND DEBURRED ALONG WITH 4EA -6 FILLERS MADE FROM 7075T6-C .020' LOT#1472548-1 PER SRM 53-70-51-2R-4;[36] FLAP PEENED THE CUT EDGE OF THE INTERCOSTAL AT RBL38 AND RBL 7 WITH 200%; IAW SRM 53-70-51-2R-4 STEP 4.F(5) PER S.O.P.M. 20-10-03;

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