An engine repair inspector reports that during a routine build-up cycle of a pw 2000 lpt; the outsid...

Attributes
ACN	793695
Time
Date	200806
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Flight Phase	ground : maintenance ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : inspector
ASRS Report	793695
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance maintenance problem : improper documentation non adherence : published procedure non adherence : far
Independent Detector	other other : 1
Consequence	other
Factors
Maintenance	performance deficiency : non compliance with legal requirements performance deficiency : scheduled maintenance performance deficiency : repair performance deficiency : installation
Supplementary
Problem Areas	Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

During normal routine up-cycle build of PW2000 lpt; the outside vendor-overhauled turbine rear hub failed build. The required fit and clearance between the 6TH stage turbine disk/hub and this rear hub is 0.000 to 0.006T (tight). This rear hub's snap diameter is 0.010 oversize. The air carrier inspection document maximum diameter is 9.600 -- this rear hub measures 9.610. Inspection document snap size of 6TH stage disk is 9.600 to 9.604. Record of measurement supplied with the 8130-3 for this part; records this snap diameter at 9.599. Reference vendor component services 8130. Callback conversation with reporter revealed the following information: reporter stated the entire low pressure turbine (lpt) section attaches to the low pressure turbine long shaft at the splined rear hub; also known as the 'coupling'; at the lpt sixth stage position. There are five stages of lpt turbines; called L-3; L-4; L-5; L-6; and L-7 on the pw 2000 engine. There are two high pressure turbines (hpt) known as T-1 and T-2. The L-3; L-4; L-5 turbines are mounted to the forward side of the L-6 coupling flange and L-7 on the aft side of this hub/coupling. Reporter stated he is an engine inspector and the 8130 serviceable tag from the outside overhaul vendor listed the rear hub diameter on the tag as less than the actual diameter he measured. The actual rear hub diameter was 0.010 oversize and prevented the continued build-up of the low pressure turbine section.

Original NASA ASRS Text

Title: AN ENGINE REPAIR INSPECTOR REPORTS THAT DURING A ROUTINE BUILD-UP CYCLE OF A PW 2000 LPT; THE OUTSIDE VENDOR-OVERHAULED TURBINE REAR HUB WAS FOUND TO BE 0.010 OVERSIZE; EVEN THOUGH THE SERVICEABLE TAG SHOWS LESS.

Narrative: DURING NORMAL ROUTINE UP-CYCLE BUILD OF PW2000 LPT; THE OUTSIDE VENDOR-OVERHAULED TURBINE REAR HUB FAILED BUILD. THE REQUIRED FIT AND CLRNC BTWN THE 6TH STAGE TURBINE DISK/HUB AND THIS REAR HUB IS 0.000 TO 0.006T (TIGHT). THIS REAR HUB'S SNAP DIAMETER IS 0.010 OVERSIZE. THE ACR INSPECTION DOCUMENT MAX DIAMETER IS 9.600 -- THIS REAR HUB MEASURES 9.610. INSPECTION DOCUMENT SNAP SIZE OF 6TH STAGE DISK IS 9.600 TO 9.604. RECORD OF MEASUREMENT SUPPLIED WITH THE 8130-3 FOR THIS PART; RECORDS THIS SNAP DIAMETER AT 9.599. REF VENDOR COMPONENT SVCS 8130. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE ENTIRE LOW PRESSURE TURBINE (LPT) SECTION ATTACHES TO THE LOW PRESSURE TURBINE LONG SHAFT AT THE SPLINED REAR HUB; ALSO KNOWN AS THE 'COUPLING'; AT THE LPT SIXTH STAGE POSITION. THERE ARE FIVE STAGES OF LPT TURBINES; CALLED L-3; L-4; L-5; L-6; AND L-7 ON THE PW 2000 ENG. THERE ARE TWO HIGH PRESSURE TURBINES (HPT) KNOWN AS T-1 AND T-2. THE L-3; L-4; L-5 TURBINES ARE MOUNTED TO THE FORWARD SIDE OF THE L-6 COUPLING FLANGE AND L-7 ON THE AFT SIDE OF THIS HUB/COUPLING. REPORTER STATED HE IS AN ENGINE INSPECTOR AND THE 8130 SERVICEABLE TAG FROM THE OUTSIDE OVERHAUL VENDOR LISTED THE REAR HUB DIAMETER ON THE TAG AS LESS THAN THE ACTUAL DIAMETER HE MEASURED. THE ACTUAL REAR HUB DIAMETER WAS 0.010 OVERSIZE AND PREVENTED THE CONTINUED BUILD-UP OF THE LOW PRESSURE TURBINE SECTION.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

An engine repair inspector reports that during a routine build-up cycle of a pw 2000 lpt; the outside vendor-overhauled turbine rear hub was found to be 0.010 oversize; even though the serviceable tag shows less.