TASK 72-50-32-200-007-A00 LPT Stage 4 Blade - Examine For Overtemperature, Inspection-007

DMC:V2500-A0-72-50-3204-01A-300A-C|Issue No:002.00|Issue Date:2016-05-01

Export Control

EAR Export Classification: Not subject to the EAR per 15 C.F.R. Chapter 1, Part 734.3(b)(3), except for the following Service Bulletins which are currently published as EAR Export Classification 9E991: SBE70-0992, SBE72-0483, SBE72-0580, SBE72-0588, SBE72-0640, SBE73-0209, SBE80-0024 and SBE80-0025.

Copyright

© IAE International Aero Engines AG (2001, 2014 - 2021) The information contained in this document is the property of © IAE International Aero Engines AG and may not be copied or used for any purpose other than that for which it is supplied without the express written authority of © IAE International Aero Engines AG. (This does not preclude use by engine and aircraft operators for normal instructional, maintenance or overhaul purposes.).

Applicability

All

Common Information

TASK 72-50-32-200-007-A00 LPT Stage 4 Blade - Examine For Overtemperature, Inspection-007

Effectivity

FIG/ITEM PART NO.

01-150

3A1804

01-150

3A2374

General

This TASK gives the procedure for the inspection of the stage 4 turbine blades.

Fig/item numbers in parentheses in the procedure agree with those used in the EIPC.

The policy that is necessary for inspection is given in the SPM TASK 70-20-00-200-501

All parts must be cleaned before any part is examined. Refer to TASK 72-50-32-100-000 (CLEANING-000).

All parts must be visually examined for damage, corrosion and wear. Any defects that are not identified in the procedure must be referred to IAE.

The practices and processes referred to in the procedure by the TASK numbers are in the SPM.

References

Refer to the SPM for data on these items.

Definition of Damage, SPM TASK 70-02-02-350-501

Inspection of Parts, SPM TASK 70-20-00-200-501

Some data on these items are contained in this TASK. For more data on these items refer to the SPM.

Chemical Processes

Surface Protection

Repair Facilities

Repair Vendors for Step and Step are listed below.

MTU
AERO ENGINES AG
Dachauer
Strasse 665
80995 Muenchen
Germany

Preliminary Requirements

Pre-Conditions

NONE

Support Equipment

NONE

Consumables, Materials and Expendables

NONE

Spares

NONE

Safety Requirements

NONE

Procedure

    1. SUBTASK 72-50-32-220-173 Examine the Stage 4 Turbine Blades for Overtemperature

      NOTE

      1. Do this inspection if the stage 3 LP turbine blades are rejected for an overtemperature condition.

      2. Before examination of the blade perform the hardness test of the stage 4 turbine disk. Refer to TASK 72-50-31-200-004 (INSPECTION/CHECK-004).

      3. Blades that were at temperatures more than the limit of 2000 deg F (1093 deg C) for a short time will cause a change in the alloy microstructure of the blade.

      4. Overtemperature condition, also for a short time, changes the structure of the gamma particles, together with a decrease of size and volume percentage. Signs of overtemperature are decrease in volume percentage of the gamma phase and compare the microstructure against a referenced standard.

      NOTE

      Do this inspection only if the hardness test of the stage 4 LP turbine disk shows no decrease of hardness. Refer to TASK 72-50-31-200-004 (INSPECTION/CHECK-004).

      1. Examine one blade for overtemperature by metallurgical analysis. Use the blade with the strongest discoloration.

      1. If the stage 4 turbine disk shows hardness loss, reject complete set of stage 4 turbine blades and vanes and examine the stage 5 turbine blades, refer to TASK 72-50-32-200-008-B00, (INSPECTION/CHECK-008, CONFIG-001) and TASK 72-50-32-200-008-A00 (INSPECTION/CHECK-008, CONFIG-002) for overtemperature.

  2. SUBTASK 72-50-32-320-056 Prepare the Stage 4 Turbine Blade for Metallurgical Analysis

    NOTE

    To accomplish this SUBTASK utilize Repair Vendors as listed in Repair Facilities.

  3. SUBTASK 72-50-32-220-174 Metallurgical Analysis of the Stage 4 Turbine Blade

    NOTE

    To accomplish this SUBTASK utilize Repair Vendors as listed in Repair Facilities.

    4. SUBTASK 72-50-32-220-175 Reject the Stage 4 Turbine Blades

    1. Reject all stage 4 turbine blades in the engine if the analysis indicates temperatures higher than 2000 deg F (1093 deg C) at one location.

    5. SUBTASK 72-50-32-220-478 Reject the Stage 4 Turbine Vanes

    1. If blade metal temperature exceeded specified limit of 2000 deg F (1093 deg C), but not more than 2050 deg F (1121 deg C), the 4th stage vanes with the following part numbers must be inspected for cracks as follows:

      PN 3A0637CL45

      PN 3A2131, 3A2274

      PN 3A2244, 3A2284

      PN 3A2417, 3A2898

      4th stage vanes with unacceptable cracks have to be rejected.

    2. If blade metal temperature exceeded 2050 deg F (1121 deg C), reject all 4th stage vanes.

    6. SUBTASK 72-50-32-220-479 Examine the Stage 5 Turbine Blades for Overtemperature

    1. If the stage 4 turbine blades were rejected because of overtemperature, examine the stage 5 turbine blades, refer to TASK 72-50-32-200-008-B00, (INSPECTION/CHECK-008, CONFIG-001) and TASK 72-50-32-200-008-A00 (INSPECTION/CHECK-008, CONFIG-002) for overtemperature.

    7. Figure: LP Turbine Blade - Inspection Areas

    LP Turbine Blade - Inspection Areas

Requirements After Job Completion

Follow-On Conditions

NONE
Change Type:

Editorial change

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