Ivor Evans is the F-35 InternationalProgramme Manager UK at LockheedMartin. Here he lays out the latestposition on the development of the JointStrike Fighter, which is planned to replacea wide range of aircraft.

It is now over two-and-a-half years sincethe Lockheed Martin X-35 Joint StrikeFighter ( JSF) Concept Demonstratorlast graced the California skies. Just a fewmonths later the LockheedMartin/Northrop Grumman/BAE SystemsTeam was awarded the contract to producea family of stealthy, affordable, supersonicmulti-role fighters destined to equip the US,the UK and International Partner aviationarms. Time does not stand still and neitherdoes work on the subsequently named F-35. Since October 2001, amongst a host ofother achievements, several majorprogramme reviews have been successfullyaccomplished, engines are under test,mission system risk reduction is under wayand, in November last year, cutting startedon the first structural components for thewing, forward fuselage and centre fuselage the first of over 7000 parts for the overallassembly of each aircraft.

Designing, developing, building andsupporting a modern combat aircraft isexpensive. The F-35 is a stealthy,supersonic multi-role fighter designed toreplace a wide range of aging fighter andstrike aircraft. Three variants derived froma common design will ensure the F-35meets the performance needs of the US,the UK and allied defence forcesworldwide, while staying within strictaffordability targets. To provide a solutionto these varying requirements, it wasnecessary to look for economies of scaleand commonality as well as employingmodern design and production techniquesfrom whichever industry was mostsuccessful at deploying them.

If this programme was to reach fruitionmuch common ground had to be found.Even to reach the stage where three USservices and the UK could agree oncommon requirements was a majorachievement and as General MikeHough, a former JSF Program Director,put it, not without much breaking of ricebowls. Additionally, there was the desireto attain interoperability with allied airforces, the lack of which has caused somuch difficulty in combined operations.

There are many areas where F-35 willprovide new advancements oropportunities lower operating costs,stealth technology for the first time in amulti-role fighter with materials thatdramatically reduce maintenanceexpenses, aerodynamic performance equalto the best current-generation fighterscombined with significantly increasedoperating ranges but as always the heartof any modern combat aircraft is itsmission systems, and here F-35 is alreadymaking great strides.

Elements of the mission capability hadbeen demonstrated during the earlierConcept Demonstration Phase, and nowthat work is being taken further in thecurrent phase. The airborne side of thiswork is being undertaken in a NorthropGrumman BAC 1-11 test bed, but this willbe augmented by the addition of a new testvehicle a modified 737 later this year.

The first phase of the F-35 Data Fusionrisk-reduction programme was started inOctober 2003. The objective of the nine-month programme is to reduce thedevelopment risk of the F-35s fusionfunctionality by evaluating keyarchitectural concepts using acombination of flight tests and flight-validated ground simulations. The F-35sfusion capability combines and prioritises

information gathered from on-board and off-board sources by way of theaircrafts various sensors. Phase One ofthe flight tests installs and integrates intothe BAC 1-11 the performancerepresentative sensors, a fourth-generation Northrop Grumman ActiveElectronically Scanned Array radar andthe Lockheed Martin Electro-OpticalTargeting Demonstration Systems.

Earlier this year, the early risk-reductionflight-test programme of the ElectroOptical Distributed Aperture System (EODAS) also began on the 1-11. TheNorthrop Grumman EO DAS will providethe F-35 with key capabilities that includemissile warning; navigation forwardlooking infrared (FLIR) which providesimagery to the pilots helmet-mounteddisplay day or night; and infrared searchand track (IRST) capability. Highresolution images from the multiple,flush-mounted DAS sensors will provide a360-degree spherical view around andthrough the aircraft, dramaticallyincreasing the pilots situational awarenessfor combat and for Short Take Off andVertical Landing (STOVL) operations.

All of this information, of course, is oflittle use to the pilot unless it is integratedin such a way that he or she cancomprehend, and the F-35 cockpit set upshows one of the most startlingdifferences from current aircraft. In mostof todays aircraft there are severalseparate display screens showing groundmapping, radar, early warning, etc. In theF-35 it is all integrated into the missionsystems avionics. The pilot views thisinformation through an 8-inch by 20-inchdisplay but has no Head Up Display(HUD). HUD duties are instead served bya Helmet Mounted Display (HMD),which enables data to be projected on tothe helmets visor.

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F-35 Joint Strike FighterMore than One Pretty Face

by Ivor Evans

PLATFORMS AND FLEXIBILITYPLATFORMS AND FLEXIBILITY

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Cockpit DisplayThe cockpit display can be divided up intofour, or ten if there is the desire to havesmall screens across the top, or it can bemade into one single or two large displays.It has been recognised that new pilots those who really understand computers are very good at changing the display to fitwhatever they need, and the F-35 will givethem the flexibility to do that. Input canbe made either by touching the screen, orthrough direct voice command. There arealso buttons on the throttle stick that giveaccess to the mission system.

Under the terms of the F-35 programme,the US Government has funded twoengine teams to provide alternativepropulsion sources. This concept is knownas Engine Interchangeability with theobjective being that installation of eitherengine is transparent to the operator. Pratt& Whitney are building the F135 engineand a GE/Rolls-Royce team are buildingthe F136. Rolls-Royce is also responsiblefor delivery of the entire STOVLLiftSystemTM, which includes LiftFanTM,three bearing swivel nozzle and roll-postducts

Pratt & Whitney began testing their firstSystem Development & Demonstration(SDD) engine ahead of time in October2003, and by July 2004 expect to have seven

engines in various phases of developmenttesting. The first engine, FX631, hassuccessfully completed all of its plannedBlock 1 testing, where it accumulated 231hours of running time including five hoursin afterburner. It is now in preparation forBlock 2. FX633, the second SDD engine,began its test sequence in January this yearand has also completed Block 1 with 122hours of successful development testing.Both engines have closely matched theirpre-test predictions. Testing of the firstSTOVL engine, FX641, is expected to beginin April 2004.

General Electric and Rolls-Royce formed aLimited Liability Company in July 2002,known as Fighter Engine Team, to developand deliver the interchangeable F136engine to compete with the P&W F135.Rolls-Royce is specifically responsible for

the Low Pressure system, combustor andgearbox and has an overall 40 per centshare in the programme, GE beingresponsible for the remaining 60 per cent.The Fighter Engine Team also has anumber of International Partners fromcountries such as Italy and the Netherlandsinvolved in the first engine test.

Assembly of the first F136 is taking placeat the GE Evendale, Ohio, facilities prior totest in mid-2004. The first entirepropulsion system (F136 with STOVLLiftSytem) will take place at the GEPeebles facilities in early 2005 in order toprove the engine interchangeabilityconcept. Successful completion of thisphase precedes full-scale development(SDD phase) from 2005. First productiondeliveries of the F136 will commence in2011.

Pratt & Whitney F135 engine under test in afterburner.

In order to minimise STOVL risk prior tofull propulsion system testing, Rolls-Roycehas been running various rig tests on theLiftFanTM system in Bristol andIndianapolis. The SDD configurationclutch just completed the full specificationrequirement of 1500 engagements.Through configuration modifications inlater builds, Rolls-Royce is working toincrease further the clutch life.

The first fully configured SDD lift fanjust completed its initial block of testingand cleared the way for acceptancetesting and later delivery of the firstSTOVL LiftFanTM to Pratt & Whitney.Lift fan gearbox and lubrication systemrigs have accumulated many hours ofdevelopment testing and havesuccessfully addressed all issues to

ensure minimum programme impact.International collaboration is one of themost prominent features of thisprogramme. The most obvious evidenceof the international perspective is thepresence of seven nations, in addition tothe US and the UK, forming the F-35partnership. The UK is the sole Level 1partner; Italy and the Netherlands joinedat Level 2; and Turkey, Canada,Denmark, Norway and Australia haveLevel 3 status. The internationalpartnership was completed whenAustralia joined around 18 months agoand, since that time, Israel and Singaporehave signed letters of agreement to joinas Security Co-operation Participants(SCP). Each of these countries haspledged sums of money ranging fromUS $2bn for the UK to around US $50M

for the SCPs, which in total has addedover US $4.5bn to the F-35 programme.One of the advantages of being a Level1, 2 or 3 partner is the ability to bid forwork on the programme on a best-valuebasis. In this respect, UK Industry hasdone extremely well reflecting the UKsexperience and capability in theaerospace field and bringing thousandsof new jobs to the country. Additionally,of course, BAE Systems is a principalpartner in the Lockheed Martin F-35Team undertaking work which rangesfrom the design and build of the aftfuselage; responsibility for crew escape,life support and EW systems; supportingthe development of Autonomic Logisticsproducts and services; and work on theSTOVL control systems.

F-35 work is going on around the globeand, following on from the earlier startof machining in the USA, in February ofthis year the BAE Systems MachiningCentre at Samlesbury in Lancashirebegan work on one of the major framesthat forms part of the aft fuselage.

In addition, the first assembly jigstructures for the F-35 have beendelivered to BAE Systems at Samlesbury.The jigs will be used to assemble theboom section of the F-35 and have beenconstructed using aluminium extrusion,rather than the traditional steel. Notonly does this make them lighter and

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F - 3 5 J O I N T S T R I K E F I G H T E R

F-35 STOVL LiftSystemTM, LiftFanTM, Three Bearing Nozzle and Roll Post Ducts.

Tom Burbage (left), Lockheed Martin Executive Vice President and JSF General Manager and Tom Fillingham, Vice President and Deputy General Manager, BAE

Systems watch the first cut.

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easier to work with, but also allows agreater flexibility to incorporate anychanges to the product across the threevariants of the F-35.

The jigs are the first of 19 majorassembly jigs that are required for theSDD phase on the Conventional Take-Offand Landing (CTOL) aircraft and furtherdeliveries will follow during 2004.

Modern weapons systems go nowhere andachieve little without the right level ofsupport, or Autonomic Logistics asreferred to on the F-35 programme, andthrough life/sustainment costs are some ofthe most significant aspects of the wholelife cost of any system. Unlike manyprevious programmes, the ability to deploy,sustain and maintain the F-35 has beengiven equal importance to capability rightfrom the start of the programme. Indeed,three of the eight Key PerformanceParameters (KPPs) are support related sortie generation rate; logistic footprint;mission reliability which isunprecedented in modern programmes.

The Autonomic Logistics (Auto Log orAL) Integrated Product Team isresponsible for the development anddelivery of Support and Training Systemrelated products and services. Key staffsare embedded within the Air VehicleIPTs to contribute to the design processand ensure that the appropriatesupportability attributes are designedinto the Air Vehicle. The AutonomicLogistics IPT is making good progresstowards its objectives. The F-35 TrainingSystem Preliminary Design Review(PDR) was successfully completed inFebruary 2004, the Auto LogInformation System (ALIS) PDR wassuccessfully completed in March 2004and the AL Critical Design Review wasscheduled for April 2004. All key reviewswere attended by representatives fromUS/UK services and InternationalPartners and there is work under way torefine plans to develop AL Operationsand Deployed AL Operations. Work isalso under way on the processes, toolsand capability which will be stood upincrementally to support the IntegratedFlight Test programme, involving

resources from all partner companiesand OEMs.

The stand-up of AL Operations andassociated infrastructure within SDDwill be used as a risk-reductionenvironment to provide verification ofAL products and capabilities that will beused to support operational assets in theUS and the UK post SDD.

The F-35 is a complex defence projectand, inevitably, there has been pressspeculation about many aspects of theprogramme including weight, budgets,schedules and system performance. It hasbeen recognised that the design of the F-35 airframe will take longer to completethan expected and consequently theprogramme has slipped by one year.However, the F-35 is in the third year ofits 11-year System Development &Demonstration phase, and investing timeand money now will ensure that theproduction and operation costs are keptmanageable, providing the Services withan affordable fighter that meets theiroperational requirements.

As part of US President Bushs FinancialYear-05 budget submission, the USDepartment of Defense is conducting acomprehensive review of the Joint StrikeFighter Programme to evaluate thecurrent status of the project and the mostefficient road ahead to achieve success.

The F-35s all-digital design givesprogramme planners the unique abilityto effect design improvements before theaircraft is built or flown, and it assures

that the best weapon system possible willemerge from the development process.

At the time of writing, the finalprogramme decisions have not yet beenmade. However, there is consensus atthe highest levels of the Navy, Air Forceand OSD, that there will not be a re-sequencing of aircraft. The developmentorder will remain Conventional Take Offand Landing (CTOL), then STOVL andthen the Carrier Vehicle (CV). Furtherdetail will be available after finalapproval from the US governmentauthorities.

The F-35 underwent an Air System DesignIntegration & Maturation Review (DIMR)in April 2004. The purpose of the reviewwas to capture all of the design work doneto-date and used Critical Design Reviewcriteria as its basis. The following monthswill be spent conducting trade studies withfocus on weight reduction across the threevariants. After the trade studies arecomplete and all of the analysis done, theAir System will then undergo a CriticalDesign Review. This review will take placewhen the design is ready.

The F-35 Joint Strike Fighter programmewill continue to face challenges, but hasthe full support of the CustomerCommunity:

We would rather take an extra year now interms of the design phase, working on theissues particularly with weight, working onthe issues with commonality to make surethat we had the right design baseline as wego forward on the airplane. GordonEngland, Secretary, United States Navy,to US Congress, March 2004.

This aircraft is a transformationalaircraft; [and Im] not surprised withsuch a transformational aircraft that wehave some challenges. The good news, isthat we're in about a 10- to 11-yeardevelopment cycle here. We're at the verystart. We have already identified thosechallenges, and we are addressing themand the contractors are addressing them.Michael Hagee, Commandant,United States Marine Corps, to USCongress, March 2004.

At the time of writing, thefinal programmedecisions have not yetbeen made. However,there is consensus at thehighest levels of theNavy, Air Force and OSD,that there will not be a re-sequencing of aircraft.