Service difficulty report · Rib · Boeing 7377H4

Difficulty date
April 14, 2023
Submitted
April 28, 2023
Operation
Air carrier
Aircraft
N412WN
Make and model
Boeing 7377H4
Aircraft serial
29818
Aircraft time
71,376 hours, 42,351 cycles
Part
Rib
Condition
Cracked
Location
Zn 300 Stabilize
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

CRACK FOUND ON THE RH HORIZONTAL RIB LOWER FLANGE AT STAB STA 193.9; 25' FROM THE LE.<REMOVED DAMAGED IN AN AREA OF 1.8' X 0.8' PER SRM 55-10-09-2R-5 REP 5.; FABRICATED; LOCATED; DRILLED; AND APPLIED CHEMICAL CONVERSION COATING AND PRIMER IAW SRM 55-10-09-2R-5 REP 5 PAR.4F-M MATERIAL USED FOR -2 ANGLE BAC1490-2793 7075T62 0.063'LOT#1491233-1; -3 FILLER 7075T6 0.050'LOT#1505777-1.;[07] PERFORMED GVI AND NO ADDITONAL DAMAGED FOUND; FABRICATED; LOCATED; DRILLED; AND APPLIED CHEMICAL CONVERSION COATING AND PRIMER ON REPAIR PARTS IAW SRM 55-10-09-2R-5 REP 5 PAR.4F-M MATERIAL USED FOR -2 ANGLE BAC1490-2793 7075T62 0.063'LOT#1491233-1; -3 FILLER 7075T6 0.050'LOT#1505777-1.;[08] VERIFIED CORRECTIVE ACTION STEPS 6 AND 7.;[09] OK TO INSTALL REPAIR PARTS;[10] OK TO INSTALL GIVEN.;[11] INSTALLED REPAIR PARTS ON RIB LOWER FLANGE AT R/H HORIZONTAL STAB STA 193.9 AND 25' FROM LE. IAW SRM 55-10-09-2R-5 REP 5 PAR.4N-Q. AND OK TO INSTALL RIB AT BS 193.9 R/H HORIZONTAL STAB.;[12] VERIFIED CORRECTIVE ACTION 11.;[13] INSTALLED R/H HORIZONTAL RIB AT STAB STA 193.9' PER SRM 55-10-09-2R-5 REP 5; DWG 182A3001 AND DWG 182A4001;[14] INSPECTED AND VERIFIED CORRECTIVE ACTION 13; RIB INSTALLATION.;[15] OK TO INSTALL ELEVATOR BALANCE PANEL BAY 4.;[16] VERIFIED CORRECTIVE ACTION 14 AND PARTIAL STEPS 1 AND 2.;[17] COMPLETED STEP 2;[18] COMPLETED STEP 1;[19] VERIFIED ALL STEP COMPLETED.;[20] VERIFIED STEP 1.;[21] VERIFIED STEP 2 AND MEASUREMENT TABLE.

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