Service difficulty report · Structure · Boeing 7472D7B

Difficulty date
June 1, 2011
Submitted
June 11, 2011
Operation
Air carrier
Aircraft
N522MC
Make and model
Boeing 7472D7B
Aircraft serial
21783
Aircraft time
108,674 hours, 21,759 cycles
Part
Structure
Condition
Corroded
Location
Bs 340
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

EO 4753B352: DURING ACCOMPLISHMENT OF SB 747-53A2562, FOUND HEAVY CORROSION AT BS 340, RBL 37, WL 120, PN 65B07935-544 TEE THROUGH VERTICAL FLANGE AS SHOWN IN FIG 1. (PROPOSED THE REPAIR SHOWN IN FIG 1 WHICH DEEMED ACCEPTABLE WITH THE FOLLOWING PROVISIONS: MACHINE THE EXTRUSION TO MAKE THE REPLACEMENT SECTION TEE AS SHOWN IN FIGURE 2 SKETCH. PENETRANT INSPECT OR SURFACE, INSPECT NEW CHORD AFTER FORMING AND HEAT TREAT TO CONFIRM CRACK FREE. ALODINE AND PRIME TWO (2) COATS OF BMS 10-11, TYPE 1, PRIMER. ALLOW TO DRY BETWEEN COATS.)

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