118. I Level Power Plants

118. I LEVEL POWER PLANTSPage 1 of 11

118. INTERMEDIATE LEVEL (I-LEVEL) POWER PLANTS FUNDAMENTALS

References:

[a] OPNAVINST 4790.2H, Naval Aviation Maintenance Program (NAMP), Vol. I

[b] NAVAIR 15-01-500, Preservation of Naval Aircraft

[c] Local Directives and Standard Operating Procedures

[d] NTSP for Gas Turbine Engine Test Systems

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[e] OPNAVINST 4790.2H, Naval Aviation Maintenance Program (NAMP), Vol. V

[f] NAVAIR 17-15-50.1, Joint Oil Analysis Program Manual, Vol. 1

.1 Discuss modular engine maintenance. [ref. a, ch. 16]

a. Modern technology and new maintenance concepts have changed some inspection and repair management procedures. Newly designed engines are constructed in separate modules, for example, compressor, combustion, turbine, afterburner, gearbox, torquemeter, or combinations thereof to simplify the repair and maintainability process. Modular engines are routinely inspected while installed using the special/phase inspection concept. They are removed only for cause, for example, LCF, failure, and maximum operating time.

b. When the engine is removed, perform the same AESR screening and pre-induction inspection process as with other engines. Repair of the modular engine is accomplished by removal and repair/replacement of the defective modules. This repair action is accomplished using the applicable CERRC and accompanying CERR SCC or with conventional MIM or WP with accompanying CERR SCC.

c. Inspection requirements subsequent to or concurrent with engine repair vary. Some modular engines, for example, F404 and T700, have engine MRC decks with accompanying SCCs. Earlier designed modular engines, for example, T400 and T56, have the QECA MRCs with accompanying SCC. Subsequent to or concurrent with repair, the inspection requirements outlined in the applicable engine MRC/QECA MRCs will be performed.

* Modular engine design allows I-level activities to readily remove and replace interchangeable modules with RFI spares. The MSR provides the method for recording the maintenance data for thesemodules and their life limited assemblies and components. A paper copy of the MSR will be attached to andaccompany the component to its final destination. The electronic CM ALS MSR record will be transferredusing CM via the WAN. Read MSR section Vol I, 13.3.16.

* The MSR composition is as follows:

(a) Module Service Record (OPNAV 4790/135).

(b) Inspection Record (OPNAV 4790/22A)*.

(c) Technical Directives (OPNAV 4790/24A)*.

(d) Miscellaneous/History (OPNAV 4790/25A)*.

(e) Preservation/Depreservation Record (OPNAV 4790/136A)**.

(f) Assembly Service Record (OPNAV 4790/106A)*.

(g) Equipment History Record (EHR) Card (OPNAV 4790/113)*.

(h) Scheduled Removal Component Card (OPNAV 4790/28A)*.

*CERR: Complete Engine Repair Requirements

* LOW CYCLE FATIGUE (LCF): A fatigue cracking failure mode that is defined by the frequency and characteristics of the loading that causes the crack. LCF is caused by stresses built up by mechanical/thermal cycles which occur only a few times per flight. The four most significant LCF events are: stop/start/stop cycles, rapid major changes in operating temperature, rapid major changes in rotational speed, and significant increases in aerodynamic loading of the blades/disks.

* AERONAUTICAL EQUIPMENT SERVICE RECORD (AESR) - An insert to the basic aircraft logbook used as a service record for various aircraft equipment, such as power plants and propellers.

.2 Discuss proper engine preservation/storage/transportation.

[ref. b, ch. 3]

1. General

Engines must bepreserved within 10 days of the last engine run. Removedengines must be stored indoors. Preservation tags shallbe attached to the engine data plate. Level I preservationis not recommended for removed engines unless theywill be reinstalled within 28 days.

a. Engines shall be cleaned, inspected, and havecorrosion control performed.

b. Operational Engine Protection.

(1) Level I. Keep fuel systems at least 95% offuel. Seal seams and openings of engine, exceptcompressor inlet and exhaust outlet, using barriermaterial, MIL-PRF-131 Class 1, held in place with tape,SAE AMS-T-22085 Type II. Tape shall only be used forsealing seams and small openings. Seal engine inlet,exhaust, and other large openings with a fitted enginecover. If covers are not available, large openings maybe sealed with barrier material, MIL-PRF-131 Class 1,held in place with tape, SAE AMS-T-22085 Type II, orwith rigid fillers secured in place with safety wire. Reinstall all lines and fittings, caps, andcovers on exposed fittings or openings. Cap fluid systemopenings with fluid-tight closures.

(2) Levels II and III Internal. Protect the enginefuel system internally with MIL-PRF-6081 Grade 1010oil using an appropriate engine test stand in accordancewith the applicable MIM. If a compressor spray isrequired, spray in accordance with instructions in theapplicable MIM.

(3) Level II External. Protect externally asspecified for Level I. Statically dehumidify engine usingdesiccant, MIL-D-3464 Type I, in accordance withinstructions for Level II External Preservation ofOperational Engines. Inaddition, cover engine with waterproof cover or shroudmade from plastic sheet, ASTM D4801 Type III, orbarrier material, MIL-PRF-131 Class 1.

(4) Level III External. Reinstall all lines andfittings, caps, and covers on exposed fittings or openings.Cap fluid system openings with fluid-tight closures.Place engine in a dehumidified bag,dehumidified enclosure, or Shippingand Storage Container.

c. Nonoperational Engine Protection. Non-operationalengines cannot be placed in Level Ipreservation because of the inability to comply with the28 day maintenance requirement.

(1) Levels II and III Internal. Protect internallywith MIL-PRF-6081 Grade 1010 oil using the "cold pres"method described in Chapter 3, Section VII.

(2) Levels II and III External. Protect the sameas for operational removed engines.

.3 Discuss inventory control of QEC accessories. [ref. a, ch. 12]

1. QEC: Quick Engine Change

2. Major Engine Inspection.

This is a comprehensive inspection performed to determine the material condition of the engine. The organizational activity removes a QECA due for inspection from the aircraft, turns it in to the supporting IMA, requisitions an RFI QECA, and installs it in the aircraft. The removed QECA is inspected by the IMA and returned to RFI status. MRCs provide all requirements necessary for performing major engine inspections, and include the inspection requirements for the engine and all applicable QEC accessories for the respective aircraft applications. These MRCs are normally used by the IMA. When O-level activities retain QEC components they will be inspected using the applicable QECA MRCs .QECA MRC tasks will be a part of CM ALS for NTCSS Optimized OMA NALCOMIS activities.

3. Definition.

1. QUICK ENGINE CHANGE ASSEMBLY(QECA) - An engine completely assembled with a QECK on a QECS with all accessories, less the propeller for reciprocating or turboprop engines.
2. QUICK ENGINE CHANGE KIT (QECK) - A kit containing all items required for a QECA, less GFE, engine, and propeller. Contractor furnished accessories may be deleted subject to approval by the COMNAVAIRSYSCOM when storage limitations, bulk, or their general nature warrant such deletion. The kit, as delivered, will be assembled as far as practical, compatible with packaging limitations.

c. QUICK ENGINE CHANGE STAND (QECS) - A structural frame, equipped with castors and floor locks on which a QECA may be mounted.

.4 Discuss the following elements of an engine test facility:

a. IMRL accountability [ref. c] : Inventory

b. Manning [ref. c]: AMO’s manning

c. Training/certification [ref. a, ch. 16; ref. d]: GTETS Operator training, certification, proficiency, and recertification requirements are outlined in Volume V, Chapter 24.

Volume V, Chapter 24.

1. The GTETS Qualifier shall:

(1) Be an E-5 or above with NEC 6422/MOS 6023 and certified as an operator in the activity.

(2) Be certified on the test cell and type engine for which training is to be provided.

(3) Receive GTETS Qualifier training from a NATEC JTS representative and be thoroughly familiar with safety and emergency procedures.

(4) Administer practical certification and recertification examinations for GTETS Operators.

(5) Assist the program manager in developing, implementing and tracking GTETS Operator proficiency training.

(6) Ensure GTETS Operators complete proficiency training conducive to maintaining required certification levels.

2. Certification

a. Formal local (in-service) training and OJT can be provided under the supervision of a NATEC JTSrepresentative or designated GTETS Qualifier for the test cell and type engine regardless of commandassigned. Training shall be obtained at the AIMD, IMA or MALS using the standardized training approvedby the NTSP in conjunction with locally prepared site specific OJT. OJT syllabuses shall be developed andmaintained by the program manager, GTETS Qualifiers, and QA personnel and be approved for use by theMO. Marine Corps personnel will use the MATMEP individual qualification record for Aircraft Power PlantTest Cell Operator (MOS 6023).

b. NATEC on-site training can be provided by a NATEC JTS representative and is normally requestedby the activity to be performed coincident with the initial installation and calibration of the test facility.NATEC on-site training can also be requested to improve technical knowledge and skill to improveoperational readiness.

c. Upon completion of training, the nominee must satisfactorily complete a written exam administeredby QA and a practical exam (pass/fail) administered by a GTETS Qualifier or NATEC JTS representative.Both written and practical examinations shall be prepared by QA, GTETS Qualifiers or NATEC JTSrepresentatives and maintained by QA. The MO will issue a letter of certification indicating the engine testsystem and type engine(s).

d. GTETS Operators and Qualifiers are required to maintain proficiency for each type engine for whichthey are certified. As a minimum, GTETS Operators and Qualifiers will run any type/model aircraft engineeach 90 days, and will run at least one engine for each type certified every 12 months. Engine runs forproficiency may be run on any type test cell with a certified operator for that test cell, and will bedocumented in the individual’s qualification/certification record. Every attempt should be made to maintainproficiency on all type engines for safety and effectiveness. Failure to maintain proficiency on one typeengine within a one-year period will result in loss of certification for that specific type engine.

e. GTETS Operators will be recertified every 24 months. Recertification will consist of a writtenexamination administered by QA and a practical exam (pass/fail) administered by a GTETS Qualifier orNATEC JTS representative on any one type engine for which they are certified. Afloat activities that areunable to operate their test cell for extended periods of time (greater than 3 months) may perform theirrecertification practical exams at another activity with a NATEC JTS representative or GTETS Qualifierdesignated in writing for that type test cell. Additionally, for planning purposes and operationalcommitments, recertification exams can be completed up to 3 months prior to the GTETS Operator’scertification expiration date. Recertification exams should place emphasis on safety and emergencyprocedures. GTETS Operators exceeding 24 months will not be considered certified until they havecompleted refresher training by a GTETS Qualifier or NATEC JTS representative and successfullycompleted a written and practical examination. GTETS Operators failing either the written or practicalexaminations will be required to complete refresher training or complete the entire OJT syllabus, asdetermined by the program manager.

f. Prior to designation, GTETS Qualifiers shall be trained by a NATEC JTS representative for the testsystem and type engine. Previous training by NATEC for initial certification as a GTETS Operator does notsatisfy this requirement. GTETS Qualifiers are not required to recertify as GTETS Operators while assignedto the same command as long as proficiency is maintained.

g. Activities without GTETS Qualifiers may request such services from the nearest activity authorizedto conduct GTETS Operator training for the same test system and type engine(s) being certified on.

h. Previously certified GTETS Operators may be certified at the discretion of the MO after successfullycompleting a written exam administered by QA and a practical examination administered by a GTETSQualifier or NATEC JTS representative. Previously certified GTETS Operators failing either the written orpractical examinations will be required to complete refresher training or complete the entire OJT syllabus, asdetermined by the program manager. Previous certification records shall be retained in the individual’squalification/certification record.

d. Technical evaluation [ref. a, ch. 16]

* Engine Test Cell Technical Evaluation: Prior to correlation, all newly constructed and significantlymodified (affecting aerodynamic or thermodynamic flow) or rebuilt fixed engine test facilities must undergoa comprehensive technical evaluation conducted by the NAVAIRWARCENACDIV Lakehurst NJ, under thedirection of COMNAVAIRSYSCOM to ensure they are suitable and supportable for use. Unless waived by

COMNAVAIRSYSCOM, a technical evaluation and an engine correlation must be satisfactorily completedbefore service engines can be made RFI and installed in aircraft. Evaluation should be requested by messageto NAVAIRWARCENACDIV and COMNAVAIRSYSCOM prior to acceptance of the facility by the localactivity resident officer in charge of construction.

e. Correlation Program [ref. c]

* Engine Test Cell Correlation. To ensure engines consistently meet all performance requirements, a test cell correlation for each engine type tested shall be conducted for all enclosed, permanent turbofan, jet, shaft, or prop engine test facilities. Test cell correlation may also be required when engine test procedures and parameters are changed or the design of engine dress kit hardware, for example, inlet screen/bellmouth or exhaust nozzle, is modified such that it could affect aerodynamic/thermodynamic flow. Outdoor (open air) jet engine test systems generally do not require correlation unless certain site-specific conditions alter airflow dynamics to the engine. Outdoor (open air) turboshaft engine test systems using a torque tube to measure torque output also require correlation. If a torque tube is replaced with a different torque tube for any reason, a recorrelation must be performed for both indoor and outdoor turbo-shaft test systems. The interval between correlation shall not exceed 3 years to maintain integrity of engine performance. However, with joint ACC/TYCOM and NAVAIRWARCENACDIV Lakehurst NJ concurrence, an extension of the correlation frequency requirement for a specific type engine test system may be granted. All activities are responsible for contacting the ACC/TYCOM and NAVAIRWARCENACDIV Lakehurst NJ concerning test cell correlation requirements.

f. Aviation electrician support [ref. a, ch. 16]

* Electrical Power Requirements: The instruments used in conjunction with the test stand are designed to operate on predetermined power ratings within relatively small tolerances. Changes in voltage or frequency or a combination of both will effect the accuracy of the instrumentation and contribute to component failures. Therefore, whenever possible station or commercial power will be used. If not available, and electrical power is supplied by a portable generator, the operator will ensure:

(1) The portable generator is 115 volts A.C., three phase, and four wire.

(2) The portable generator is monitored to ensure its voltage and frequency remain stable.

g. Calibration [ref. a, ch. 16]

* Jet Engine Test Facility Calibration: I-level activities with calibration capability will use calibration intervals cited in the Metrology Requirement List.

(1) A qualified operator and an electrician will be available at all times to assist during calibration and work by the field team representatives.

(2) A list of known instrument discrepancies will be compiled and made available to the calibration team.

h. Scheduled maintenance [ref. a, ch. 16]

* The appropriate engine shop(s)/work center(s) will verify SERNOs of installed SRC/EHR/ASR or CM ALS components during the inspection/repair action. To preclude extensive disassembly, only those accessories/components which are exposed during required maintenance actions need be verified. The inventory is performed using a locally prepared form containing a preprinted list of SRC/EHR/ASR or CM ALS components with a column provided for recording the serial numbers and part numbers of the installed items. NTCSS Optimized OMA NALCOMIS activities use the Life Limited Component Report PART II to verify component SERNOs and part numbers. It is desirable to ensure RFI engines have all SRC/ASR or CM ALS items with sufficient time remaining to reach the next scheduled engine removal.

i. Fuel requirements [ref. c; ref. e, ch. 3]

1. The Power Plants and Test Cell Supervisor shall:

(1) Ensure integrity of fuel systems during routine maintenance, including covers/caps on open or removed fuel cells, lines, and components.

(2) If contamination is present, assist QA in conducting an immediate investigation of the aircraft/test cell fuel system and components to determine the source of contamination.

NOTE: If the source of contamination is not isolated to a particular fuel cell/tank, the refueling source shall be determined and the cognizant activity Fuels Officer/Supervisor notified.

(3) Refer to the MIMs and T/M/S NATOPS for possible specific gravity and minimum flow setting adjustment if aircraft/test cells have been serviced with fuels other than JP-5.

(4) Ensure non-RFI and inactive fuel cells/tanks are properly preserved and protected against contamination.

j. Operational coordination [ref. c]

k. Documentation [ref. a, ch. 13]

1. Report: Engine Transaction Report and End of Quarter Engine Report.

For those O-level and I-level activities with reportable engines refer to NAVAIRINST 13700.15 for reporting procedures.

2. Aeronautical Equipment Service Record

(1) Engines.

Phase and major engine inspection records are maintained on one page. Special and conditional inspections are maintained as separate pages within this section of the AESR. The record providesspace for identifying the type of inspection performed. The left column of the record is titled "Type orDescription of Inspection" to facilitate proper descriptive entries for individual inspections. All phaseinspections, special inspections, conditional inspections, and major engine inspections (except fluid sampling,engine wash, recurring special engine inspections not requiring NDI or disassembly/reassembly, or servicing) require AESR entries by the activity performing the inspection. This includes those engine inspectionsperformed as a part of the aircraft phase inspection.

l. FOD prevention [ref. e, ch. 12]

m. SE requirements [ref. c; ref. e, chs. 17, 18]

.5 Discuss the environmental controls required to support an oil analysis lab.[ref. f, ch. 4]