1、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-8573A 28 7447406 0186385 6 MIL-E-8593A 1. SCOPE 1.1 Scope This specification establishes the performance, operating characteristics, design features, detailed interface configuration definitions,
2、and installation envelopes for turboshaft and turboprop engines. It also establishes the demonstrations, tests, reports, inspection procedures, and other data required for satisfactory completion and acceptance, by the Using Service, of the Preliminary Flight Rating Tests (PFRT) and the Qualificatio
3、n Tests (QT) for the engines. Further, this specification identifies the tests, procedures and data required for satisfactory completion of the Acceptance Tests (AT) of production units of either.mode1 engine. Notwithstanding the requirements for test verification of individual points of performance
4、 or operating characteristics of the engines covered by this specification for purposes of PFRT, QT, or AT, the engine manufacturer/contractor shall continue to be Eully responsible for all features, characteristics, and perormance o the engine throughout the environmental conditions and operating e
5、nvelope, to the extent required by the applicable contract. This specification also establishes the content and format to be used by the engine contractor for the preparation of the engine specification in accordance with 6.5. 2. APPLICABLE DOCUMENTS 2.1 Documents. The applicable documents listed in
6、 the following document, of the issue specified in the engine specification, form a part of this specification to Che extent specified herein: MIL-BULLETIN-343 Documents Applicable to Aircraft Engines and Propellers, Use of (Copies of- listed federal and military specifications, standards, drawings,
7、 and publications required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting oficer.) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-8593A 3. REQUI
8、REMENTS 3.1 Item Definition. A brief description of the salient features of the engine shall be provided in the engine specification. To be included in this description, where applicable, shall be a-description of such components as compressor including number of stages, variable geqmetry provisions
9、, acceleration bleeds; combustor type including method of fuel injection; turbine components including number of stages, cooling provisions; exhaust nozzle; speed decreaser provisions; engine control features; .accessory gearbox provisions; type.of lubrication and scavenge system; starting and ignit
10、ion system; nhmber and location of main bearings; instrumentation and performance indicating provisions. The performance ratings shall be specified in the engine specification in accordance with. Tables I and II. . A detailed engine characteristics summary shall be included as shown in Tables III an
11、d IV. Terms, symbols, and their , definitions shall be in accordance with section 6 and with ARP 755. 3. l. 1 .Item Diasrams. Item diagrams shall; be provided when required by the Using Service. 3.1.2 1nterface“Definition. The interface requirements include all physical installation requirements and
12、 performance requirements necessaty for instaliation of the engine. All interface definitions shall be shown on the engine configuration and envelope drawing or in the text describing the applicable functional system. 3.1.21 Drawinss. shall form a Dart copies .of theie fi The following drawings, as
13、figures, of the engine specification. Reduced size .gures shall be included in the engine Specification. a. Enqine Confiquration and Envelope Fiqure. This drawing shall include detailed profiles in all planes to show and identify the physical interface features of the engine. The drawing shall show
14、mounting details and tolerances for the erigine and all installation items, . clearances for installation and removal of accessories anti . components subject to separate removal, access for adjustments and other maintenance functions, and center of gravity of the complete bare .engine. .This drawin
15、g shall show the maximum space required by the engine including tolerances and dimensional changes due to manufacturing, 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-8593A thermal effects, vibration, and operating and externally- applied l
16、oads. b. Electrical Installation Connection Fiqure. This drawing shall show and identify all engine systems external electrical circuit requirements and installation interface connection details. 3.1.2.2 Mock-up. When required by the Using Service, a full scale mock-up shall be prepared and a mock-u
17、p inspection shall be held in accordance with ANA Bulletin No. 406 3.1,2,3 Installation Interfaces. Engine features affecting engine installation interfaces shall be identified and defined in the engine specification. 3.1.2.4 Moments of Inertia. The following shall be specified in the engine specifi
18、cation. a. The maximum effective mass moment of inertia of the complete dry engine about three mutually perpendicular axes with the origin at the center of gravity. b, The maximum effective mass moment of inertia of each engine rotor system about the resultant rotational axis, together with the effe
19、ctive direction of rotation of .the inertia and the direction and location of the resultant rotational axis, For engines with geared rotor systems, the shaft to which all inertias of each rotor system have been algebraically referred shall be specified. c. The maximum effective mass moment of inerti
20、a of the complete power output system (including the reduction gear train) referred to the output shaft speed. 3.1.2.5 Externally Applied ForceS. The engine shall function satisfactorily under the conditions specified in 3.1.2.5.2, 3,1,2.6 and.figure 1 and shall withstand those conditions without pe
21、rmanent deformation, The engine shall also not fail when subjected to static loads equivalent to 1,5 times those values but the engine need not operate satisfactorily thereafter, The limit loads shall be based on a mass factor consisting of the dry mass of the engine, increased by the specific mass
22、allowed for all engine mounted accessories and operating fluids. In installations where airframe components are supported by the engine, the 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking
23、permitted without license from IHS-,-,-MIL-E-8593A arrangement shall be compatible with ground handling equipment specified by the Using Service, 3,1,2.6.2 Enqine Stiffness, The estimated stiffness of the engine in resisting loads and moments applied at the outboard end of the output shaft, relative
24、 to the engine mounting points, shall be stated in the engine specification, The first “free-free” lateral and vertical engine bending mo.des shall be specified, 3,1.2,7 Pads. and Dyives. Pads and drives suitable for . mounting and driving the engine componente and aircraft accessories shall be in a
25、ccordance with the basic configuration and rating requirements specified in the engine specification and presented as shown in Table V. The engine component drive system and the accessory drive systems (engine accessory drive gearbox and power take-off drive) shall be capable of simultaneous operati
26、on of all the drives when each drive is subjected to the maximum permissible torque or power rating specified for the individual drive, All drive splines, except the tachometer generator drive spline, shall be positively lubricated by engine oil. Complete dimensions and details of the drive pads tog
27、ether with clearance envelopes shall be shown on the engine configuration and envelope figure. No part of the gearbox shall, prevent independent removal of any one accessory mounted on these drives, Pads and drives for accessories and components shall con,form to the appropriate MS 3325 through MS 3
28、329 standards, The tachometer drive shall conform to AND 20005. Gearing for the tachometer generator drive pad shall provide a speed of 4200 f 25 RPM at the maximum continuous rotor speed limit. 3.1.2.7.1 Power Take-off (PTOL. When power take-off shafts . are provided for driving aircraft accessorie
29、s, the ratings, clearance envelopes, dimensions, pad and connection details, accessibility and alignment requirements shall. bb specified in the engine specification and on-the engine configuration and envelope figure. The design and configuration of the power take-off shafts shall conform with the
30、applicable poztions of 3.1.2.7 and 3,7,9, 3.1.2.8 Enqine Surface Temperature and Heat Rejection. The maximum operating surface temperatures of the engine .and heat rejection rates shall be specified in an appendix to . the engine specification, Factors such as accessory pad loadings, compressor air
31、bleed conditions, oil system Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-8593A cooling requirements and air andgas leakage from engine case flanges and split lines shall be taken into consideration in establishing engine heat rejection rate
32、s. The surface temperature and heat rejection rates shall be presented in graphical form as shown in figure 2. The conditions surrounding .the engine, the engine power condition, and the oil system temperatures for which the surf.ace temperatures are applicable shall be shown. For components and acc
33、essories on the surface of the engine, the specified component and accessory surface temperature and heat generation curves may differ from the engine temperature as shown by the dashed lines on figure 2. . The engine surface emissivity shall be presented as shown on figure 3. The heat rejection and
34、 surface temperature data presented shall be for the conditions listed below. If heat rejection rates during flight or ground operating conditions other than those listed .below are critical or limiting, those data also shall be presented. - a. Maximum power., Sea Level, static 52OC day. b. Maximum
35、power, Sea Level, -39OC ambient, maximum stagnation inlet air temperature. c. Maximum power, 11 km or maximum altitude, maximum stagnation inlet air temperature. 3.1.2.8.1 .Enqine Component Limitinq Temperature. Engir-e components mounted on the engine shall not exceed their allowable temperatures w
36、hen surrounded by still air under the following conditions: ,a. Continuous operation with ambient air at the maximum stagnation temperature. b. Flight shutdown from the most adverse condition and continued soaking with ambient air at maximum stagnation temperature. c. Ground shutdown with ambient ai
37、r at the standard sea level temperatura with no sFecial cooling such as forced ventilation, refrigeration, or rotation of rotors. A tabulation of the maximum ambient air temperature surrounding each component and the limiting surface temperatures for all components shall be provided. These temperatu
38、res sha-ll-fr3flece maximum stagnation temperature 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-8593A and engine surface temperature heating effects. The specific points of measurement, where the ambient air temperature and surface tempera
39、ture with respect to the three coordinate axes of the component are maximum, shall be defined in the engine specification. The contxactor shall tabulate, by components, the surface and air temperatures and time periods applicable to the most severe conditions within the environmental conditions and
40、operating envelope of the engine. 3.1,2,8,2 Heat Rejection and Coolins Test Report. An engine heat rejection and cooling requirements test report shall be submitted to the Using Service prior to the initiation of the PFRT. This report, based upon test data, shall verify the analytical heat rejection
41、 and surface temperature data presented in 3.1.2.8. An engine heat rejection and cooling schematic diagram showing component and station locations, including temperature limits, shall be included in the heat rejection and cooling report. 3,1.2,9 Air and Gas Leakaqe. The location, amount, temgerature
42、 and pressure of engine leakages shall be specified in the engine specification. There shall be no locations where leakage flow will be of sufficient temperature and concentrated impingement to present a safety hazard or affect installation requirements, in the judgment of the Using Service. 3*1.2*1
43、0 Enqine Air Inlet System. 3,1,2,10.1 Air .Inlet Desiqn and Dimensions. Unless otherwise specified by the Using Service the engine shall have an inlet attachment flange and this flange shall be designed to accept either axial through bolts or a quick- disconnect: clamp, Interface dimensions for the
44、attachment of the inlet duct shall be shown on the engine configuration and envelope figure. 3.1.2,10.2 Allowable Inlet Connection Stresses. The maximum allowable shear load, axial load, and overhung moment at the engine inlet flange shall be specified in the engine specification, Provided by IHSNot
45、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-8593A 3.1.2.10.3 Inlet Airflow Distortion Limits. At the -option of the Using Service, one of the following procedures will be used to define inlet airflow distortion limits. PROCEDURE I : a. . Not less than five (
46、5) sets of inlet flow distortion data and corresponding engine .operating conditions shall bedefined and specified in the engine specification, for which stable engine bperation shall occur. The inlet distortion criteria defined and specified shall result from one or more -of the following at the di
47、scretion of the Using Service: technical coordination between the airframe and engine contractors, dictated by the Government, or left to the engine contractor to define. Compressor surge or stall under the specified conditions shall be considered a flight safety item and is not acceptable. For each
48、 set of inlet flow distortion data specified, the engine interface operating conditions shall be defined, as applicable, in terms of mach number, altitude, power setting, customer airbleed, power extraction, etc. Measurements of the engine inlet total pressure, temperature, and flow variation shall
49、be made at the engine/inlet aerodynamic interface which shall be defined in the engine specification. All inlet instrumentation utilized in measuring airflow, Fressures and temperatures, the arrangement, location, response and instrumentation accuracies shall be defined and specified in the engine .specification. For each set of specified inlet flow distortion data, the total airflow, average total pressure recovery
