COMMERCIAL DERIVATIVE AIRCRAFT AND TURBINE ENGINE
COMMERCIAL DERIVATIVE AIRCRAFT AND TURBINEENGINEIlan BerlowitzBedek Aviation Group, Aircraft & Programs Division, Israel Aerospace Industriesiberlow@iai.co.ilKeywords: Level of Safety, Tailored Aircraft Certification Criteria, Airworthiness Seams, Levels ofApprovalsAbstractA Commercial Derivative Aircraft (CDA) is acommercial off-the-shelf produced aircraft with anFAA Type Certificate (TC). The aircraft may bemodified for use as a Military aircraft. Militarymodifications may be fully or partially FAAapproved to civil statutes for the purpose ofretaining airworthiness certification.The key concept of this paper is that the futureof military transport aviation will be based onprocurement of commercial derivative aircraft &turbine engine. The purpose of this paper is toexamine various methods of civil and militaryairworthiness systems integration.Military specifications are concerned mainlywith performance (payload, range, endurance),while civil standards mainly focus on flight safety.This paper discusses certification procedures andairworthiness requirements applied to CDA.Differences between civil and militaryapproach to aircraft flying qualities, structure,avionics, and turbine engine certification anddevelopment of harmonized procedures forcertification of CDA are examined. Also exploredare areas of weakness with the currentcertification processes.Wright aircraft was the first poweredcommercial derivative aircraft to be purchased bythe military. It was also the first performancebased military contract for a power aircraft with arequirement to exceed 40 MPH (the Wrightaircraft flew at 42 MPH).IntroductionUtilizing civil type certification for CDA is notnew. It has been in use for many years on an adhoc basis. However, efforts by the military toprocure commercial aircraft and re-qualify theaircraft using the organic military process typicallyfail. The primary objective for using the civilcertification process is initially to maintain theairworthiness and design integrity inherent in thebaseline type-certificated aircraft.In an effort to standardize iness Certification Criteria] was createdin October 1st 2002. Civil and militaryairworthiness processes both rely upon managingand mitigating risk. Civil type certification reliesupon minimum flight safety standards. Militaryairworthiness manages risk through performancecriteria.Because the two systems are designed fordifferent purposes, the two systems and theirprocesses are not entirely compatible. However,examination of technical design standards andflight safety requirements reveal that the criteriaused to define civil and military “airworthiness”have more in common than not.When the military mission parallels themission the civil aircraft is designed to perform,using civil type certification standards to modifyand convert the aircraft for military use can be themost cost effective and efficient solution. Cargotransport and a multitude of special missionaircraft fall into this category when the military &mission aircraft can be operated and maintained ina manner consistent with the original civil designcriteria.The modern military depends on internationalpartnerships, and both the import and export ofaviation products. Those international militaryaviation partnerships will be very similar to thecivil model for bilateral aviation agreements that1
ILAN BERLOWITZexist today. While the role of civil and militaryaviation will always be different, CDA is the firststep towards increased cooperation and futureharmonization of regulatory processes.BackgroundMilitary airworthiness authorities rely on civilregulatory material for military type certificationand design change certification programs, such asairworthiness design standards; FAA 14 CFR,EASA CS, etc., and associated advisory material;FAA Advisory Circular (AC), EASA AcceptableMeans of Compliance (AMC), etc.Civil processes provide an excellent basis formilitary aircraft programs. However, civil targetlevels may be different for military aircraft,equipment or missions. There are significantmilitary / civil gaps in the following areas: Civil aircraft handling qualities or flyingqualities (controllable, maneuverable andtrimmable) requirements do not adequatelyaddress military tactical roles / missions / tasksrequirements in the intended operatingenvironment. Civil airworthiness standards have noequivalent for weapon systems. Military & mission aircraft often operate in aharsher environment, more severe thanequivalent civil aircraft. Military & mission aircraft may operate in ahostile environment requiring the use of selfdefense technologies. Militarywartimeoperationsincludeextremely hazardous missions underconditions of operational necessity. Military roles / missions / tasks are unique andhave no civil equivalent. Military performance requirements demandtechnology advances, which may notsufficiently mature to be civil certified.Flight Safety & AirworthinessAviation safety consists of three factors: Human: the active part of flight operations. Machine: aircraft systems and structure. Environment: the external factors thatinfluence flight, including nication.Safety factors can be seen as three links of a chain.The failure of a single link is sufficient for anaccident to occur. Pilot error can put an aircraft injeopardy, and in most cases, the pilot cannotcompensate for a serious aircraft failure. A methodused to delineate "significant hazard" is a riskreduction technique known as "As Low asReasonably Practicable (ALARP)”. A risk isALARP when it has been demonstrated that thecost of any further risk reduction is grosslydisproportionate to the benefit obtained from thatrisk reduction. The civil flight safety concept isbased on FAA / EASA Advisory Circular AC25.1309-1A / Acceptable Means of ComplianceAMC 25.1309 [System Design and Analysis]: A single failure should not prevent continuedsafe flight and landing regardless of itsprobability. A subsequent failure during the same flight,whether detected or latent, and a combinationthereof, should also be assumed, unless thejoint probability (with the first failure) isshown to be extremely improbable.The Level of Safety (LOS) is generally based onan acceptable accident rate. LOS in civil aviationwas established as a maximum of 1.0E-9 for eachfailure condition with a catastrophic effect. MILSTD-882E [System Safety] identifies and classifiesmilitary systems hazards and is approved for useby all military departments and defense agencieswithin the United States Department of Defense(DoD).Level of safety for military & mission aircraftis based on a risk assessment process. Theassociated probability of occurrences for military& mission aircraft is higher than the equivalentcivil aircraft due to the nature of their purpose. Afactor of 10 is often used when comparing amilitary & mission aircraft with an equivalent civilaircraft. When this military standard is required,the Severity Category: Catastrophic / ProbabilityLevel: Improbable, probability of occurrence isless than 1.0E-6.Airworthiness represents a fulfillment of thenecessary requirements for safe flying, within theallowable operational limits: A safe condition is the freedom fromconditions that can cause death, injury ordamage to equipment.2
COMMERCIAL DERIVATIVE AIRCRAFT AND TURBINE ENGINE Achievement of the necessary requirementsmeans that the aircraft, or any of its parts, aredesigned and built to fly in safe conditions. Allowable limits means that the aircraft isdesigned for operation within a certain flightenvelope, including speed, load factors,altitude and operational conditions such asvisual flight rules (VFR), night flight,instrument flight rules (IFR) and icing.Airworthiness is defined in the UK MilitaryAviation Authority (MAA) MAA02 [MilitaryAviation Authority Master Glossary] as: "Theability of an aircraft or other airborne equipmentor system to be operated in flight and on theground without significant hazard to aircrew,ground crew, passengers or to thirdparties throughout its lifecycle”.Flight safety is often viewed as synonymouswith airworthiness (see Table 1). However,airworthiness is concerned mainly with theapproved configuration of the aircraft at the timeof certification and is primarily focused on theability of the aircraft to perform safe flight andlanding. Flight safety is one element of the entirecertification basis and is based on reliabilityevaluation techniques and lessons learned fromaircraft incidents and accidents.Flight SafetyFlight safety is the systematicprocess involving justification offunctionalintegrity,andidentification and resolution ofpotential hazards. This process isanalytically driven, toward safeproduct and irrespective of anyairworthiness regulations.It is often required by regulationsFAA 14 CFR / EASA CS Part25.1309 [Equipment, Systems, andInstallations]. Functional integrityis justified upon certification.However, the resolution of hazardsis never fully satisfied. The flightsafety field continually monitors thedesign and operational safety risksthrough a continuous process ofhazard identification and trendmonitoring throughout the systemlife-cycle.Depending on contract, the safetyanalysis usually ends upon issuanceof the final safety assessment. Thesafety issues remain relevant duringthe entire life-cycle of the productand require continuous and carefulengineering, usually via some sortof safety management system(SMS).AirworthinessDemonstration of conformancefor an airframe or airbornesystem to a set of specificregulations for a specific typeand category of aircraft asdetermined by the airworthinessauthority.Airworthiness is regulationdriven to show compliance withaccepted standards.Airworthiness is satisfied assoon as it is objectively proventhat the regulations andrequirements for a specificaircraft type and category aremet. The process is typicallyconcluded with the authorityissuing a TC, or in the case of amodification, a STC.The process terminates uponthe authority issuing the TC orSTC.Airworthinessisconsidered to be compromisedif configuration differs fromthat specified in the TC / STC.Table 1: Flight Safety & AirworthinessHarmonization of Civil & MilitaryRegulationsIn general, there are two parts to the militaryqualification procedures: Military airworthiness qualification is anactivity concerning the verification ofcompliance with applicable airworthinessrequirements. Military performance qualification concernscompliance with contractual performance andfunctional requirements.Two difficulties related to CDA certification areunique roles such as military transportation,airborne cargo deployment, low level operation,air-to-air refueling, and rules for civil / militarynavigation & communication in Air TrafficManagement (ATM).Over time, these two situations are occurringmore frequently and special documentation isbeing issued by civil aviation authorities to addressthem. For example, in the USA, FAA AdvisoryCircular AC 20-169 [Guidance for Certification ofMilitary and Special Mission Modifications andEquipment for Commercial Derivative Aircraft(CDA)] has been generated to provide guidance.Airworthiness Certification ToolsThe U.S. DoD acquisition procedures are reflectedin Air Force Policy Directives AFPD 62-6,NAVAIR Instruction 13100.15, Army Regulation70-62, and MIL-HDBK-516. The roles andresponsibilities of the FAA Military CertificationOffice (MCO) are defined in FAA Order8110.101A [Type Certification Procedures forMilitary Commercial Derivative Aircraft].Table 2 illustrates the FAA involvementspectrum in various programs. The first column isregarding CDA that fall under AFPD 62-4[Standards of Airworthiness for PassengerCarrying Commercial Derivative Aircraft]. Thesecond column is regarding CommercialDerivative Aircraft that fall under AFPD 62-5[Standards of Airworthiness for CommercialDerivative “Hybrid” Aircraft].C-32, C-37, C-40E-3, E-4, E-8, KC-10B-1, B-2Air ForceAir Force responsibleAir Force responsibleresponsible forfor qualification offor all qualificationcontinuednon- FAA equipment.and .Heavy FAA Involvement No FAA InvolvementTable 2: FAA Involvement Spectrum3
ILAN BERLOWITZFAA Order 8110.101AFAA Order 8110.101A was published andavailable on the FAA regulatory and guidancelibrary under “Orders and Notices”: Defines role of the “FAA Military”certification and procedures for all typecertification approval for military & missionconversion / modification of commercialderivative aircraft. Provides special guidance and procedures forConformity and Compliance findings formilitary special mission equipment and uniquemilitary functions. Contains procedures, guidance, and policyessential for Military Program Offices(MPOs) and contractors pursuing commercialderivative programs. Provides instructions on how to manage theAirworthiness Seams between FAAapproved type design and militaryconfiguration for “hybrid” aircraft. Establishes guidance and policy for Levels ofApprovals which support later militaryapproved modifications.FAA Certification of CDA from FAA Order8110.101A is supplementing by FAA Order8110.4C [Type Certification] with key issuesregarding CDA airworthiness role andresponsibilities.Airworthiness SeamsThe dividing line between FAA certification andMIL-HDBK-516 approval is determined at thepoint where FAA certification no longer satisfiesmilitary airworthiness criteria for components,systems or installations on the military & missionaircraft configuration. For example air refuelingsystem operating, proof and burst pressures 120PSIG, 240 PSIG and 360 PSIG (MIL-A-19736A),compared with civil aircraft fuel system 60 PSIG,120 PSIG and 180 PSIG respectively.The military handbook is the all-inclusiveairworthiness guide for acceptance of military &mission aircraft, airworthiness qualification andvalidation. Verification criteria must be developedand defined for installations, systems, orcomponents for which FAA certification are thiness process. The key to success for well-defined Tailored Airworthiness CertificationCriteria (TACC) is airworthiness integration andunderstanding the similarities and differencesbetween military and civil certification.There is some degree of similarity between thestructure of MIL-HDBK-516 and FAA 14 CFR.However, the military handbook is not detailed asFAA 14 CFR. It is intended to be used inconjunction with the DoD Joint ServiceSpecification Guide (JSSG) StandardizationProgram document, and the FAA 14 CFR, as acheck list, to define the airworthiness certificationbasis.Levels of Civil & Military CertificationApprovalsThe FAA may certify certain non-essential or noncritical electrical / avionics Government FurnishedEquipment / Special Mission Equipment (GFE /SME) when all of the below criteria are fulfilled: Access to the necessary data is not limited. The applicant has demonstrated that the GFE /SME function does not interfere, duringnormal operation or failure conditions, withcritical or essential functions of equipment thatare necessary for safe flight and landing of theaircraft. The military airworthiness authority issues astatement that the GFE / SME complies withthe designed specifications, and Unless otherwise specified, the GFE / SMEmust be certified to meet all other FAA 14 CFRrequirements.If it is not desirable, practical, or possible, to fullycertificate GFE / SME equipment as part of thetype design, therefore, other possible options are: Full Approval: military & mission aircraftwhich meet the same applicable airworthinessregulations of a civil aircraft including: typedesign data, compliance ntenance and continued airworthinessdocumentation. Installation Approval: CDA authorized formilitaryoperationswithappropriatelimitations / restrictions for civil operations. Provision Only (partial approval): Provisiononly approval allow modifications or definelimits for military installations. An aircraftmay be certified and operated with provisions4
COMMERCIAL DERIVATIVE AIRCRAFT AND TURBINE ENGINEfor GFE / SME. The provisions should be fullydefined and must comply with all applicableFAA 14 CFR requirements. Safe Carriage (partial approval): an aircraftmay be certified with GFE / SME installed, butnon-operational (wire bundles are capped andstowed, “inoperative” placards are installed,etc.). The FAA 14 CFR requirementsapplicable to the aircraft type design must bemet with the installed GFE / SME in the nonoperational state. FAA 14 CFR Part 21.3[Reporting of Failures, Malfunctions, andDefects] requires design approval holder toreport to the FAA about certain failures,malfunctions, and defects on type certificatedproducts, which include CDA. The MCO mustbe notified by Certificate ManagementAircraft Certification Office (CMACO) aboutthe FAA 14 CFR Part 21.3 with reports onpotential to affect the CDA. Where MCO is theCMACO, design approval holders must reportdirectly to the MCO.Commercial Derivative Aircraft FlyingQualitiesHandling qualities or flying qualities is an attemptto subjectively measure the capability of anairplane and its human operator to complete aspecific task within defined performance limitsand within reasonable physical, mental and skillbounds for the pilot or crew. There are both a taskcompletion element and a workload element inthese subjective measures.The military developed much of the literatureand did most of the early research on such pilotvehicle interactions. One of the most commonlyused rating schemes is the Cooper-Harper ratedscale published in NASA Technical ReportsServer (NTRS) TN D-5153 [The Use of PilotRating in the Evaluation of Aircraft HandlingQualities].Advisory Circular AC 25-7C [Flight TestGuide for Certification of Transport CategoryAirplanes], Appendix 6 [Correction of AirMinimum Control Speed to Standard Conditions],details the FAA Handling Qualities Rating Method(HQRM) which bears considerable resemblance tothe Cooper-Harper scheme and shows thecorrelation between the two. It includes also twoelements; atmospheric conditions, and probabilityof occurrence.Tailoring rules are as follows: Identify each criterion as applicable, partiallyapplicable or non-applicable, consideringaircraft class, flight phase category and level. Identify the applicable or non-applicableportion of a criterion partially applies. Fully applicable criteria may not be deleted ormodified. Develop additional criteria as appropriate.Standards and methods of compliance may betailored, considering complexity, capabilitiesand intended use.It is expect that each contract in the U.S. will spellout what elements or subsystems of the CDAshould be covered by MIL-STD-1797A / MIL-F8785C [Flying Qualities of Piloted Aircraft]requirements.Commercial Derivative Aircraft StructureA military & mission aircraft differs from a civilcommercial transport aircraft, in the type ofloading it is subjected to and in the environmentalconditions. Both aspects are much moredemanding for a military & mission aircraft.Unlike the new generations of civil aircraft,where the usage of composite materials isbecoming extensive for principal structuralelements, the military & mission derivativeaircraft are still mainly metallic. This is becausethe baseline models are usually not the newestones. It is also common that the military & missionaircraft is derived from “second market” civiloperation.There are three important differences betweena military & mission aircraft and its civilcounterpart: Physical Configuration: The structuralmodifications introduced in a civil aircraftconverted into a military & mission aircraft arestrongly dependent on the intended usage,which is the driver of the specific equipment(antennas, lights, sensors, mission kits, etc.)that has to be installed. Usage: Commercial aircraft are operated manymore hours per day (actually, a commercialaircraft might have ten times as many lifetimeflying hours as a military & mission aircraft ofsimilar age). Furthermore, and in contrast to5
ILAN BERLOWITZthe predictable profiles of the civil commercialflights, mainly constrained by the internationalair traffic rules, the military & mission aircraftare designed to operate in changing scenarioswith highly demanding missions. ng to climb up to optimum cruiselevel, cruise at optimum speed, descent andlanding. Military & mission aircraft usuallyincludes several climbs and descents, loiters,and / or special maneuvers such as airrefueling. The cruise altitude, generallyoptimum for transport flights, may vary formilitary & mission aircraft from a fewthousand feet to the aircraft ceiling, being bothconditions equally probable. In a similar way,for a given flight profile in terms of altitude orduration, the number and / or kind ofmaneuvers made by the aircraft may differsignificantly depending on the intended usage. In-service Management of the StructuralIntegrity: Actually, the starting point is thesame, as commercial derivative aircraft usuallyretain the core of the civil certification basis,so the damage tolerance philosophy based onFAA 14 CFR and / or EASA CS Part 25.571[Damage tolerance and fatigue evaluation ofstructure] or FAA 14 CFR Part 26 [ContinuedAirworthiness and Safety Improvements forTransport Category Airplanes] regulations,are applicable to both. These regulationsclearly state the need of establishing anappropriate maintenance program to preventthe failure of any structural element whichwould cause a catastrophic failure of theaircraft during the life of the aircraft. Inpractice, the so-called Usage BasedMaintenance (UBM) is used in the vastmajority of the aircraft which are currentlyflying. The UBM is based in the determinationof an inspection program which ensures thedetection of any damage before it reaches acritical size. The inspection program isdetermined based on the assumption of adetermined usage of the fleet, and therefore, ifthe actual usage of a given aircraft departs ofthe predefined hypotheses, the maintenanceprogram has to be adapted to ensure thecontinued airworthiness. In the case of the civiltransport aircraft, the manufacturers usuallyanalyze periodically the actual usage of theplatforms by means of fleet surveys to ensurethat the maintenance program is adequate. Ifthis analysis concludes that the fleet is beingused in a different way as considered todetermine the maintenance program, this isupdated accordingly. In the case of the military& mission commercial derivative aircraft, therange of possible missions is increased and thedetermination of an envelope inspectionprogram which ensures the continuedairworthiness of the whole fleet becomes a notaffordable exercise. To cope with thisdifficulty, these aircraft are fitted with Healthand Usage Monitoring Systems (HUMS),which allow an Individual Aircraft Tracking(IAT) of each unit of the fleet. In the mostsophisticated forms of these systems, theyincorporate also an Operational LoadsMonitoring (OLM) subsystem. The HUMS /OLM form essential part of the structuralintegrity management of the fleet, allowingdetection of deviations of the actual usagefrom the certified usage; this enables theimplementation of corrective actions to themaintenance program if required.Commercial Derivative AvionicsAvionics are the electrical systems used onaircraft.Avionicsystemsincludecommunications, navigation, the display andmanagement of multiple systems, and thehundreds of systems that are fitted to aircraft toperform individual functions. These can be assimple as a searchlight for a maritime aircraft or ascomplicated as the tactical system for an airborneearly warning platform.Avionics plays a heavy role in themodernization of the next generation of the airtransportation system in six areas: Routes and Procedures - improvednavigation and routing. Trajectories - adding data communications tocreate preferred routes dynamically. Delegated separation - enhanced situationalawareness in the air and on the ground. Low Visibility / Ceiling Approach /Departure - allowing operations with weatherconstraints with less ground infrastructure.6
COMMERCIAL DERIVATIVE AIRCRAFT AND TURBINE ENGINE Surface Operations - to increase safety inapproach and departure. AirTrafficManagement(ATM)Efficiencies - improving the ATM process.The cockpit of an aircraft is a typical location foravionic equipment, including control, monitoring,communication, navigation, weather, and anticollision system.Production CDA combines Civil & MilitaryFlight Management System (FMS) and integratescontrol of the military radios and navigationalequipment. “Second market” CDA incorporatescivil / military switch to allow the flight crew toselect either to fly in civil mode using the originalcivil aircraft equipment’s data or in military mode,by switching all data lines necessary to provide theflight plan and guidance data from the MilitaryFMS.The military FMS is not FAA TSO. Themilitary FMS system is composed of: Military FMS Control Display Units (CDUs). Commercial Avionics Full-Duplex SwitchedEthernet (AFDX). Data Transfer Unit (DTU).The military FMS provides an interface to sendflight planning and guidance data to the CockpitDisplay System (CDS) and Flight Director /Autopilot (FD / AP) system.The CDUs, the data transfer unit and theEthernet switch are connected via an AvionicsSystems Local Area Networks (LANs) for thepurposes of data loading of operational flightprogram software and flight plan files andhardware redundancy.The Military FMS interfaces to and receivenavigation data from the following sources: New Dual Embedded GPS / INS (EGI). Existing Air Data Inertial Reference Unit(ADIRU) / Digital Air Data System (DADS). New civil GPS with FAA TSO-145 [AirborneNavigation Sensors Using the GlobalPositioning System (GPS) Augmented by theWide Area Augmentation System (WAAS)]capability.The selection between civil or military mode is tobe executed on ground or in flight. In civil FMSmode; takeoff and landing, thrust management,vertical guidance, and CAT-IIIa auto-land areprovided via dual FMS and / or autopilot flightdirector system (AFDS). In military FMS mode,the Military FMS provides guidance for departure,climb, cruise, and ingress to the active militaryflight pattern / procedures. Usually the MilitaryFMS does not interface with the aircraftMaintenance Control and Display Panel (MCDP),Engine-Indicating and Crew-Alerting System(EICAS), and Electronic Engine Controller (EEC).Civil specification and standards consist ofARINC 424 [Navigation System Data Base],ARINC 429 [Digital Information Transfer System(DITS)], ARINC 615A [Software Data LoaderUsing Ethernet Interface], ARINC 708 [AirborneWeather Radar], ARINC 818-1 [Avionics DigitalVideo Bus (ADVB) High Data Rate], RTCA DO160 [Environmental Conditions and TestProcedures for Airborne Equipment], DO-254[Design Assurance Guidance for AirborneElectronic Hardware], DO-178B [SoftwareConsiderations in Airborne Systems andEquipment Certification], RTCA ARP d or Complex Aircraft Systems], and ARP4761 [Guidelines and Methods for Conducting theSafety Assessment Process on Civil AirborneSystems and Equipment].Military specifications and standards consist ofMIL-STD-1553B [Military Standard Digital TimeDivision Command / Response Multiplex DataBus], MIL-STD-810 [Test Method Standard forEnvironmental Engineering Consideration andLaboratory Tests], MIL-STD-461 [Requirementsfor the Control of Electromagnetic InterferenceCharacteristics of Subsystems and Equipment],MIL-STD-464 [Electromagnetic EnvironmentalEffects Requirements for Systems], MIL-STD1472 [Human Engineering Design Criteria forMilitary Systems, Subsystems, Equipment andFacilities], and MIL-HDBK-217 [ReliabilityPrediction of Electronic Equipment].FAA Order 8110.101A provides extensiveguidance relative to avionics, whether productionor secondary market converted CDA. MIL-STD810, DO-160, MIL-STD-498, DO-178B, etc. canall be utilized, based on the agreements /acceptance outlined in the civil certitude matrixbetween the U.S. DoD procuring entity and theFAA. Chapters 6, 7, 8, and 9 in Order 8110.101Aprovides guidance on packaging functionality ofsystems (avionics included) relative to unique7
ILAN BERLOWITZmilitary functions, use of full civil approval,limited civil approval, and safe carriage equipmentapproval.There is great flexibility allowed between theDoD and FAA in airworthiness approval of CDA.Examples: For the KC-10A “Extender”, the completedaircraft, including refueling boom, wing hosepods, all avionics (including militaryfunctionality) was civil type certificated as theKC-10A left the Douglas production line. For the Boeing KC-46A “Pegasus” it will leavethe Boeing production line as a civil certified767-2C "Provisioned Freighter", and be stuffedwith the remaining systems / equipment at acompletion center. How the stuffing’s areapproved, whether FAA or reserved to the U.S.Air Force, would be reflected in the agreed civilcertitude matrix.Commercial Derivative Turbine EngineCivil markets frequently exist for aircraft enginesoriginally developed and qualified for use by theU.S. military. There are methods that can be usedto take advantage of this situation bysimultaneously satisfying the requirements forFAA engine certification, with minimal impact onthe primary military engine qualification program.Commercial derivative engines in a militaryconfiguration, role and environment can createspecific and sometimes unique problems thatrequire ongoing diligence and generate significantdemand for engineering resources, for example: Specific configuration mostly to support theupgrade of the Integrated Drive Generator(IDG) required for the CDA missioneq
airworthiness criteria MIL-HDBK-516 [Airworthiness Certification Criteria] was created in October 1st 2002. Civil and military airworthiness processes both rely upon managing and mitigating risk. Civil type certification relies upon minimum flight safety standards. Military
Three Spool aero derivative industrial gas turbine hot-end drive. Intake-Radial inlet LP Compressor- Axial compressor 6 stages. Air deliver to an intercooler HP Compressor- 14 stage. Over pressure ratio 42:1 Combustor – SAC/DLE HP Turbine- Two stage IP Turbine- two axial stages that drive the LP /Power Turbine. LP/Power Turbine- five stage free power turbine. 3600 RPM 60-Hz and 3000 RPM 50 .
- B734 aircraft model added - B735 aircraft model added - E145 aircraft model added - B737 aircraft model added - AT45 aircraft model added - B762 aircraft model added - B743 aircraft model added - Removal of several existing OPF and APF files due to the change of ICAO aircraft designators according to RD3: A330, A340, BA46, DC9, MD80
required to "talk turbine." Many airlines and corporate flight departments recommend reading it before interviewing and prior to attending ground school. THE TURBINE PILOT'S FLIGHT MANUAL THE TURBINE PILOT'S FLIGHT MANUAL Gregory N. Brown Mark J. Holt Gregory N. Brown Mark J. Holt TM Brown & Holt ASA-TURB-PLT4 THE TURBINE PILOT'S .
Spatial filters : Sharpening 1st VS 2nd derivative sharpening 1st derivative sharpening produces thicker edges in an image 1st derivative sharpening has stronger response to gray level change 2nd derivative sharpening has stronger response to fine details, such as thin lines and isolated points. 2nd derivative sharpening has double response to .
operation and environment of the gas turbine and information from the O&M Manual and TILs. GE heavy-duty gas turbine designs incorporate provisions in both compressor and turbine casings for borescope inspection of intermediate compressor rotor stages, first, second and third-stage turbine buckets, and turbine nozzle partitions. These provisions are radially aligned holes through the .
connected by a shaft. The range of head, in which the Pelton turbine is used, is between 60m and more than 1,000m. The Pelton turbine has quite a high efficiency and can be in the range of 30% and 100% of the maximum design discharge for a one-jet turbine and between 10% and 100% for a multi-jet turbine. /1, 3/ Figure 1.1: Pelton Turbine /3/
1,250 C gas · 7% performance (thrust/weight) improvement expected · Ceramic turbine built but not tested. M-DOT micro-turbine engine Silicon nitride inlet nozzle and turbine Palm size gas turbine engine (thrust type) φ25 mm turbine, 400k rpm All metal components Ran a few minutes. Turbine blades melted! 1998: DARPA – M-Dot
derivative and utility gas turbines studied. Once it was es tablished that a higher efficiency could be achieved with the utility gas turbine, the other two gasifiers were not examined with the aero-derivative turbine. Excess process heat from the gasification and gas turbine sections was use
