Service difficulty report · Compressor · Boeing 747422

Difficulty date
March 9, 2002
Submitted
May 14, 2002
Operation
Air carrier
Aircraft
N117UA
Make and model
Boeing 747422
Aircraft serial
28810
Aircraft time
13,772 hours, 1,767 cycles
Engine
Pwa PW4056
Engine time
13,772 hours, 1,767 cycles
Part
Compressor
Part serial
C27856
Condition
Failed
Location
Nr 1 Engine
Part time
13,772 hours, 1,767 cycles
Stage of operation
CL
How discovered
O
Nature of condition
R
Precautionary procedure
J, A

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

What was found

STALL ON TAKEOFF CONFIRMED NR 1 ENGINE POSITION 3 LOUD BANGS. WINDS 2820 TO 40 SFOLM-EMC LANZA PER CREW VERBAL 3 BANGS AT 300 FEET AGL EPR 1.51 V2 184 APRX 190 KNOTS NO ENGINE PARAMETER CHANGES NOTED AT TIME OF STALL OR AFTER ALL ENGINES RAN NORMAL. ENGINE EXPERIENCED A GROUP 3 SURGE. SURGE IS CAUSED BY EXCESSIVE BLADE TIP CLEARANCES IN THE HPC REAR STAGES. ENGINE WAS REMOVED AND PERFORMED TEST-21 AND FAILED. THE COMPRESSOR WILL BE OVERHAULED.