Service difficulty report · Stiffener · Boeing 737

Difficulty date
March 9, 2022
Submitted
April 11, 2022
Operation
Air carrier
Aircraft
N468WN
Make and model
Boeing 737
Aircraft serial
33858
Aircraft time
58,378 hours, 34,580 cycles
Part
Stiffener
Condition
Cracked
Location
R/H Horiz. Stab.
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

RT HORIZONTAL STAB AT RIB 129.5; #4 STIFFENER IS CRACKED AT THE LOWER END RT STAB L/E @ STAB STA 129.5 / [01] REMOVED RIGHT HAND HORIZONTAL STABILIZER RIB AT STAB STA 129.50 TO ACCESS RIB REPAIRS IAW SRM 51-40-02-0G-0.;[02] APPLICABLE REPAIR FOR THIS CRACKED HORIZONTAL STAB RIB STIFFENER LOWER END IS SRM 55-10-09-2R-4.;[03] CUT AND REMOVED CRACK DAMAGE FROM THE VERTICAL STIFFENER IAW SRM 55-10-09-2R-4 STEP 4.B.1.DIMENSIONS L=1.80' X W=0.050'.;[04] VERIFIED CORRECTIVE ACTION STEPS 1;2 AND 3.;[05] REQUESTED HFEC INSPECTION OF CUT EDGES OF STIFFENER AND WEB AND ALL HOLES WITHIN REPAIR AREA FOR CRACKS IAW SRM 55-10-09-2R-4 STEP 4.C & D.;[06] ACCOMPLISHED HFEC INSPECTION OF DAMAGE CUTOUT AND HOLES IN REPAIR AREA NO CRACK NOTED IAW 737 NDTM PART 6; 51-00-00 PROCEDURE 23 AND 16 TOOL# ATS2407 AND IS000450;[07] ACCOMPLISHED A GVI INSPECTION OF ALL AREAS WITHIN REPAIR FOR CORROSION; EXISTING REPAIRS OR ANY OTHER DEFECTS; NO DISCREPANCIES FOUND IAW SRM 55-10-09-2R-4 STEP 4.E.;[08] FABRICATED REPAIR PARTS; T-SECTION 7075-T76511 0.063' THICK LOT# 1463618-1; ANGLE BAC1490-7075-T62 0.063' THICK LOT# 1464923-1 AND SHIM 2(EA) 7075-T6 0.016' THICK LOT# 1439717-1 IAW SRM 55-10-09-2R-4 STEP 4.F - J.[13] INSTALLED REPAIR PARTS AND APPLIED FILLET SEAL TO REPAIR PARTS IAW SRM 55-10-09-2R-4 STEP 4.M - Q.;[14] OK TO INSTALL RIGHT HAND HORIZONTAL STABILIZER INSPAR RIB AT STAB STA 129.50 PREVIOUSLY REMOVED (STEP 1) TO ACCESS REPAIRS.