Service difficulty report · Stringer · Boeing 74747UF

Difficulty date
May 24, 2010
Submitted
May 25, 2010
Operation
Air carrier
Aircraft
N408MC
Make and model
Boeing 74747UF
Aircraft serial
29261
Aircraft time
49,344 hours, 7,670 cycles
Engine
Ge CF680C2B1F
Part
Stringer
Condition
Damaged
Location
Bs 550 S31l
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

DAMAGE WAS FOUND TO THE 142U0086-198 STRINGER 31L AT BS 550 AFTER A BURST EQUIPMENT COOLING EXHAUST VALVE TRUCK THE S-31L STRINGER AND SKIN. REFER TO EO 4453A362 FOR THE SKIN REPAIR. THE 142U0086-198 STRINGER IS MADE FROM 0.050 INCH THICK 7075-0 SHEET PER QQ-A-250/12 HEAT TREATED TO T62 AFTER FORMING. IN THE AREA OF THE DAMAGE, STRINGER HAS A MACHINE TAPER 0.050 TO 0.040 INCH OVER 197 INCHES. PART 1 OF THIS EO ACCOMPLISHES THE TIME LIMITED REPAIR OF THE STRINGER. THE REPAIR IAW PART 1 OF THIS EO IS CATEGORY C AND REQUIRES REPETITIVE INSP IAW PART 2 OF THIS EO AT A-CHECK INTERVALS AND REPLACEMENT AT THE NEXT C-CHECK AFTER 24MAY2010 IAW PART 3 OF THIS EO. PART 2 OF THIS EO REPETITIVELY INSPECTS THE PART 1 REPAIR TO ENSURE CONTINUED AIRWORTHINESS. PART 3 OF THIS EO ACCOMPLISHES THE INTERIM REPAIR AT THE NEXT C-CHECK AFTER 24MAY2010 IAW SRM 53-00-03, FIGURE 201, REPAIR 3.

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