Service difficulty report · Frame Splice · Boeing 74748EF

Difficulty date
July 23, 2011
Submitted
July 29, 2011
Operation
Air carrier
Aircraft
N419MC
Make and model
Boeing 74748EF
Aircraft serial
28367
Aircraft time
67,971 hours, 11,520 cycles
Part
Frame Splice
Part number
65B025393
Condition
Cracked
Location
Bs 2598
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

A CRACKED HOLE WAS DETECTED ON THE RT BULKHEAD FRAME SPLICE FITTING. THE CRACK (APPROX. 0.03 INCH LONG) IS REMOVED BY OVERSIZING THE HOLE THROUGH THE STACKS TO 0.341 INCH. THE HOLE ON THE SPLICE FITTING ONLY IS OVERSIZED TO 0.505 INCH TO PROVIDE AN INSURANCE CUT AND A FREEZE PLUG MADE FROM 7075-T6 IS INSTALLED IAW SRM 51-20-07. THE WASHER THAT RETAINS THE FREEZE PLUG IS 0.610 INCH DIA. , 0.170 INCH THICK AND IS MADE FROM 17-7PH CRES IAW AMS 5528, HEAT TREATED TO 180 TO 200 KSI TO TH1050 REQUIREMENTS.

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