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SDR 2007UALA02002

Open the Markdown

Service difficulty report · Compressor · Boeing 747422

FAA SDR system

Difficulty date
June 13, 2007
Submitted
June 15, 2007
Operation
Air carrier
Aircraft
N107UA
Make and model
Boeing 747422
Aircraft serial
26900
Aircraft time
36,144 hours, 4,499 cycles
Engine
Pwa PW4056
System (JASC)
7230 · Turbine Engine Compressor Section
Part
Compressor
Condition
Stalled
Location
Nr 2 Engine
Stage of operation
TO
How discovered
O
Nature of condition
R, A
Precautionary procedure
C

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

What was found

ABORTED TAKEOFF DUE TO NR 2 ENGINE COMPRESSOR STALL. [08-08-07] ACFT NR 3 ENG FERRIED TO SFO FOR ENGINE CHANGE. ENGINE REPLACED AT SFO ON 06/15/07. SHOP TEARDOWN FOUND ONE 6TH STAGE VSV VANE ARM BROKEN OFF AT THE "CLAW" TO THE ARM RADIUS AT THE 6:00 POSITION. THE ADJACENT ARM WAS CRACKED 50% ACROSS. THE DISCONNECTED VANE RESULTED IN A VIBRATORY SOURCE THAT EXCITED, AND INDUCED A FATIGUE FRACTURE IN, ONE 7TH STAGE BLADE AT ITS ROOT ATTACHMENT. THIS BLADE LIBERATED, RESULTING IN HEAVY LEADING AND TRAILING EDGE DAMAGE TO THE 7TH THROUGH 15TH STAGE BLADE AIRFOILS.