Service difficulty report · Sill Drain · Boeing 73771B

Difficulty date
August 20, 2024
Submitted
October 2, 2024
Operation
Air carrier
Aircraft
N7852A
Make and model
Boeing 73771B
Aircraft serial
29371
Aircraft time
51,472 hours, 32,335 cycles
Part
Sill Drain
Condition
Corroded
Location
Zone 200
Stage of operation
IN
How discovered
V
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

AFT FLOOR STRUCTURE - MULTIPLE SPOTS CORROSION ON R/H MOP SILL BS 947+17.5 RBL 53/BS 967+5; BS 967+6.5; BS 967+13; BS 967+14 RBL 49; BS 967+7; BS 967+17.5 RBL 51/ BS 987+2.5; BS 987+5; BS 987+10.5 RBL<[01] REMOVED CORROSION ON ASD AT MULTIPLE SPOTS CORROSION ON R/H MOP SILL<BR>BS 947+17.5 RBL 53; WL208 1'X.5'X.0.025<BR>BS 967+5; BS 967+6.5; WL208 1'X.'X.0.008<BR>BS 967+13; BS 967+14 RBL 49; 1'X.'X.0.012<BR>BS 967+7; BS 967+17.5 RBL 51 1'X.'X.0.011<BR>BS 987+2.5; BS 987+5; 1'X.'X.0.006<BR>BS 987+10.5 RBL 1'X.'X.0.010<BR>ORIGINAL THICKNESS IS .80'; LOWEST POINT OF THE CORROSION DAMAGE IS 0.025'; FOUND TO BE OUT OF LIMITS PER SRM 53-70-15-1A-1. USING MICROMETER ID:ATS1672 DUE DATE:03/2025;[02] SUMMARY STATEMENT: REMOVED CORROSION ON ASD AT MULTIPLE SPOTS CORROSION ON R/H MOP SILL<BR>BS 947+17.5 RBL 53; WL208 1'X.5'X.0.025<BR>BS 967+5; BS 967+6.5; WL208 1'X.'X.0.008<BR>BS 967+13; BS 967+14 RBL 49; 1'X.'X.0.012<BR>BS 967+7; BS 967+17.5 RBL 51 1'X.'X.0.011<BR>BS 987+2.5; BS 987+5; 1'X.'X.0.006<BR>BS 987+10.5 RBL 1'X.'X.0.010<BR>ORIGINAL THICKNESS IS .80'; LOWEST POINT OF THE CORROSION DAMAGE IS 0.025'; FOUND TO BE OUT OF LIMITS PER SRM 53-70-15-1A-1. USING MICROMETER ID:ATS1672 DUE DATE:03/2025<BR>REMOVED AND REPLACED ASD MOPSILL AT BS907 - BS1006; RBL51; WL208 PER SRM 51-40-02-0G-0; BOEING DWG 147A8501 REV: A;[03] VERIFIED RII CORRECTIVE ACTION ITEM 2; CARD COMPLETE.

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