Service difficulty report · Blade · Boeing 747422

Difficulty date
July 2, 2008
Submitted
July 15, 2008
Operation
Air carrier
Aircraft
N128UA
Make and model
Boeing 747422
Aircraft serial
30023
Aircraft time
33,819 hours, 4,090 cycles
Engine
Pwa PW4056
Engine time
31,121 hours, 5,960 cycles
Part
Blade
Condition
Damaged
Location
Hpc
Stage of operation
CR
How discovered
O
Nature of condition
M, J
Precautionary procedure
E, A

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

ENGINE EGT WENT UP RAPIDLY, ENGINE SHUT DOWN. RTFL. ENGINE WAS REPLACED AT LAX PRIOR TO FURTHER FLIGHT. SHOP TEARDOWN REVEALED THAT FIVE HP COMPRESSOR STAGE-6 BLADES HAD LEADING EDGE FOD. ONE ADDITIONAL STAGE-6 BLADE HAD A SMALL 'SHARK BITE' FROM ITS TRAILING EDGE NEAR THE TIP. THE REMAINING COMPRESSOR STAGES HAD SEVERE IMPACT DAMAGE. THERE WAS NO DAMAGE ON STAGE-5. ROOT CAUSE IS ATTRIBUTED TO FOD.