Service difficulty report · Frame · Boeing 7377H4

Difficulty date
May 12, 2023
Submitted
June 21, 2023
Operation
Air carrier
Aircraft
N429WN
Make and model
Boeing 7377H4
Aircraft serial
33658
Aircraft time
66,602 hours, 39,316 cycles
Part
Frame
Part number
UNKNOWN
Condition
Corroded
Location
Zn 100 Fus Lower
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 FRAME AT ACB BS947 LBL9 WL180..<[01] VERIFIED APPLICABILITY OF SRM 53-70-07-01-1 FOR IDENTIFICATION AND SRM 53-00-07-1A-1 FOR ALLOWABLE LIMIT;[02] REMOVED CORROSION FROM AFT CARGO BAY FRAME INNER CHORD BS 947 LBL9 WL 180 IN AREA OF 5' X 1.25' ORIGINAL MATERIAL THICKNESS 0.063' IAW SRM 51-10-02-0G-0;FRAME IS CRACKED AT BS 947 LBL 9 ON INNER CHORD FLANGE. CRACK IS 1.1 INCHES LONG AND MARKED IN RED INK.;[06] ORIGINAL MATERIAL THICKNESS 0.063' REMAINING MATERIAL THICKNESS 0.056' UP ON FARTHER INVESTIGATION WE FOUND CRACK 1.1' LONG AT INNER CHORD OF FRAME BS 947 LBL 8 FOUND TO BE OUT OF LIMIT IAW SRM 53-00-07-0G-0 PAR 4A(1); REMOVED ACB FRAME BS 947 BETWEEN STR 23L AND STR 23R IAW SRM 51-40-02;[09] LOCATED AND DRILLED NEW AFT CARGO BAY FRAME ITEM#147A1047U48 LOT#1528039-1 AT BS 947 BETWEEN STR 23L AND STR 23R IAW SRM 51-40-05-0G-0 AND DWG#147A1047; OK TO INSTALL NEW FRAME.INSTALLED NEW AFT CARGO BAY FRAME P/N 147A1047-48; LOT#1528039-1 AT BS 947 LBL 23 TO RBL 23 WL 180 IAW SRM 51-40-2-0G-0 AND DWG#147A1047;[12] VERIFIED CORRECTIVE ACTION #11.;[13] VERIFIED MEASUREMENTS.

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