New structures, newopportunities

1/2012

Customers + Partners Products + Services

Simple principle,great action

MTU Aero Engines Holding AGDachauer Straße 66580995 Munich • GermanyTel. +49 89 1489-0Fax +49 89 1489-5500info@mtu.dewww.mtu.de

Technology + Science

The ultimate in precision

A test like no other

The PurePower® PW1524G engine is being subjected to stress test-ing in MTU Aero Engines’ large development test cell. These tests arerequired by the airworthiness authorities for engine certification.Pages 6 - 11

A test like no other

New structures, new opportunities

They are reliable, durable and extremely effective, and advanced air-craft engines can hardly do without them: MTU’s brush seal are nowbeing used also on the new PurePower® PW1100G-JM geared turbo-fan, which will power the Airbus A320neo.Pages 28 - 31

Simple principle, great action

MTU Aero Engines has refined a manufacturing process that is vastlysuperior to conventional electrochemical machining: precise electro-chemical machining (PECM). Pages 24 - 27

The ultimate in precisionGermany’s Bundeswehr is to be completely revamped. REPORT inter-viewed Michael Schreyögg, Senior Vice President, Defense Programsat MTU since 2008, about the implications of the reform and theopportunities it might bring. Pages 12 - 15

6 – 11

Customers + Partners New structures, new opportunitiesKnights in red-and-white armor

12 – 1516 – 19

Technology + ScienceTaking off with sustainable fuelThe ultimate in precision

20 – 2324 – 27

Products + ServicesSimple principle, great actionAttention to detail that paid off

GlobalOn-site, on-wing support

28 – 3132 – 35

36 – 39

40 – 43ReportThe silent giant

In Brief Masthead

Contents

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Arab airline Emirates is the largest A380 customer worldwide. Thegiant aircraft is also a favorite amongst passengers—thanks in largepart to the quiet GP7000 engines, in which MTU has a significant share.Pages 40 - 43

The silent giant

Cover Story A test like no other

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More REPORT in digital formFor multimedia features in theeMagazine and in the iPadapp go to www.mtu.de/report

Editorial

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Dear Readers:

No other engine program in MTU’s long history has met with such immediatesuccess as the PurePower® PW1000G geared turbofan, which has amassednearly 2,000 firm orders and options even before delivery of the first pro-duction engine. This success is not entirely surprising; together with ourpartner Pratt & Whitney, we have invested a great deal of money and know-how in this novel engine configuration over many years, for we had full con-fidence from the outset that it would be the ideal powerplant for the aircraftof the future.

The investment phase is not yet over: To deliver the necessary quantities ofhigh-pressure compressors, we are constructing a new shop in Munich toaccommodate the center of excellence for blisk production. We are alsoworking on an innovative manufacturing process for these high-tech mod-ules. Precise electrochemical machining (PECM) will enable us to processeven the hardest materials, such as those used for the rear stages of thehigh-pressure compressor, to an unprecedented degree of precision usinga non-contact, wear-free process. We are currently maturing our PECMprocess for volume production, once again demonstrating MTU’s innovativeclout. The geared turbofan stands out not only by virtue of its advancedtechnology but also as an example of funds put to good use. Both the high-pressure compressor we designed in collaboration with Pratt & Whitney andMTU’s unique high-speed low-pressure turbine are based on technologiesdeveloped under national and European research funding programs.

The GTF will form the basis of a new generation of aircraft engines capableof reducing fuel burn and the associated carbon dioxide emissions by 30percent in three successive stages by 2035. It represents a worthwhile andsustainable investment that will promote clean aviation and at the sametime secure high-tech jobs. So MTU has written another memorable pagein the annals of international aviation history, once again bearing witness tothe excellence of German engineering. The message we wish to transmit isthat MTU’s products, processes and services will continue to serve as abenchmark in the global aerospace industry.

Sincerely yours,

Egon BehleChief Executive Officer

Cover Story

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A testlike noother

By Patrick Hoeveler

In this extremely complex test environment, absolute preci-sion is the name of the game. Extensively instrumented forthe test runs, the PurePower® PW1524G is surrounded by amaze of cables, with sensors and instruments all over theplace. Only an expert can figure out where all the wiringgoes. There are almost 1,000 measurement points on theengine to power the Bombardier CSeries. The high-tech testsare being conducted in MTU Aero Engines’ large develop-ment test cell in Munich. The telemetry tests—the biggestchallenge in engine testing—are required by the airworthinessauthorities for engine certification.

he so-called stress tests, which are among mostdemanding and complex engine tests, are car-ried out only once in the life of any engine pro-

gram. On Pratt & Whitney’s PW1524G geared turbofanengine, MTU conducts these tests to verify tempera-tures and stresses in the low-pressure turbine. Fromthe sheer number of people in attendance in the con-trol room, you can tell that the tests are far from run-of-the-mill work. The third of the series of nine devel-opment engines is being used for telemetry testing tomeasure blade vibrations in the low-pressure turbine.“We’re using this engine to check the clearance con-trol system in the turbine, and to verify the thermody-namic design. This data is important for us to predictfuel consumption,” explains Dr. Christian Winkler,Director, Business Development and GTF Programsat MTU.

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Cover Story

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Munich is already the third place to which the engine has been sentfor testing. Following first trials on Pratt & Whitney’s outdoor testfacility in sunny West Palm Beach, Florida, it was relocated toManitoba, Canada, for cold weather evaluations and initial naturalicing tests. The engineers again and again inspected their test enginein every detail. Now, the experts are focusing their entire attention onthe high-speed low-pressure turbine, which is developed and manu-factured by MTU. It is a key component of the geared turbofan, inwhich a reduction gear decouples the fan from the turbine, allowingboth components to operate within their respective optimal speedranges and thus reducing fuel consumption and noise emissions.

MTU last conducted this kind of stress testing on the V2500 engine.But this time around, it is the very first time that the company isinvolved in these important engine runs as early as in the validationphase. “We’ve never carried out this type of tests at such an earlystage of a commercial program before. This shows just how muchfaith Pratt & Whitney has in our capabilities,” says Dr. Anton Binder,Executive Vice President, Commercial Programs at MTU. Winkleradds: “These trials will allow us to expand our engineering and test-ing know-how and boost our reputation.” MTU’s experts in Munichare no strangers to engine testing, frequently conducting enduranceand other tests. On its test beds, the company also runs the Inter-national Aero Engines V2500, and the Engine Alliance GP7200 for theAirbus A380. The German company is responsible for the low-pres-sure turbine and other components that go into these engines.

What makes the tests on the PW1524G so challenging is the highlysensitive instrumentation required. For the vibration measurements,for example, strain gages made of extremely fine wire—thinner than ahuman hair—are attached to the turbine blades. Kurt Scheidt, SeniorManager, Engine and Flight Testing, explains: “When the engine isrunning, the stresses cause the electrical resistance to change. Havingcalibrated the instruments beforehand, we’re able to tell exactly whichcurrent change corresponds to which strain. Moreover, we can alsodetermine the frequency at which the blade is moving.”

The strain gages must be able to withstand the high temperaturesand enormous centrifugal forces inside the engine; they are eithercemented in place or embedded in ceramic material. On the blade,thin wires run from the strain gages to the center of the rotor; theytoo must be secured very carefully by the MTU engineers. These wiresextend into the engine shaft and are connected to the rotating tele-metry transmission unit, which sends the data to the stationaryreceiver. “It takes several weeks to set up all the instrumentation. You

The Bombardier CSeries will be powered by PW1524G engines. Entry into service is slated for late 2013.

The PW1524G engine is being prepared for test runs at MTU inMunich. The geared turbofan engine is undergoing last preparations before it is subjected to stress testing on MTU’s test cell.

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Cover Story

engine. However, turbine overspeed is not that easy to achieve, evenwhen you increase the thrust.” The MTU engineers had to delve deepinto their bag of tricks to find a solution, and installed an array ofvanes weighing almost 2.5 metric tons in front of the air inlet to thegeared turbofan. This inlet swirler, as it is called, deflects the air flowby five degrees, making it stronger and relieving some of the stresson the fan. At the outlet, an enlarged nozzle area likewise relieves thestress on the fan, and it is thus able to turn faster.

The data collection equipment on the test stand was upgraded specif-ically for the current tests. While the stationary and transient valuesfrom the standard measurements are automatically transmitted toPratt & Whitney in East Hartford in real time, the telemetry data isrecorded in a data storage unit. It takes weeks to evaluate the infor-mation. In the process, MTU’s turbine module team compares thefindings with the design model and, by studying the deformation ofthe blades, is able to draw conclusions regarding their all-importantclearance. Ultimately, what it boils down to is this: The smaller thegap between the blade and the casing, the more efficient the turbine.Incidentally, a team from the United States travelled to Munich to wit-ness the tests. Winkler reports that “communication between Pratt &Whitney and MTU is extremely good.” Everyone knows each other.Indeed, “the U.S. engineer on site previously worked over here withus on the PW6000.”

Even after stress testing has been completed, the third PW1524Gdevelopment engine will still have an important role to play. Once itswork in Munich is done, it will be transported back to the United Statesfor telemetry testing on the fan and low-pressure compressor. Andthen, the current plan is to return it to Canada for further icing testsas part of the certification process.

The MTU development test facility has a similarly busy schedule: AV2500 SelectTwo engine, the upgraded version of the original V2500,is already waiting to take the place of the PW1524G. Then, in the sec-ond quarter of the year, comes the turn of the next geared turbofan—the PW1217G for the Mitsubishi Regional Jet. MTU’s experts in Munichwill carry out stress tests on this engine’s low-pressure turbine too.Thereafter, in late 2012, endurance testing will commence on thegeared turbofan, which is slated to undergo 3,000 simulated flightcycles. “All these tests serve to find out how the various parts of theengine change during operation, and whether or not their service lifecorresponds to predictions,” explains Binder, who is pleased to reportthat the partners are happy with the results to date: “By and large, thefindings are proving extremely positive. They’re some of the best testresults I’ve seen in my whole career. We’re incredibly close to match-ing the design values.”

“Increasing MTU’s share in the geared turbofan program has resultedin a significant rise in the company’s engine test work as well,” saysBinder. MTU’s share in the PW1524G was increased from 15 to 17 per-cent, and now includes the first four stages of the high-pressure com-pressor in addition to the low-pressure turbine.

While final assembly of the PW1524G is takingplace in the Canadian city of Mirabel nearMontreal, Europe, too, will boast a productionline for the PW1100G-JM that will power theAirbus A320neo—at MTU in Germany. To date,orders have been received for almost 500 air-craft to be equipped with this geared turbofanvariant. “The decision to assemble thePW1100G-JM in Germany has already beenmade,” states Dr. Anton Binder, Executive VicePresident, Commercial Programs at MTU. “Wewill be doing the work in Munich.” Productioncould commence as early as mid-2015. This iswhen MTU will be able to benefit from the expe-rience it gained final assembling the PW6000.

A bestseller “made in Germany”

For additional information, contactDr. Anton Binder+49 89 1489-2884

For interesting multimedia services associated with this article, go towww.mtu.de/report

can barely see the rotors for all the wires and cables,” says Scheidt.During the tests, electric current is passed through the sensors at asampling rate of 100 kilohertz, or 100,000 times per second.

The trials are scheduled to last a month, during which the actual enginerunning time will be around 30 hours. In order to analyze the bladevibrations, the engine has to be run up slowly and at a constant rate.Scheidt describes the process: “We spend two minutes going fromidle to 105 percent of the rated turbine speed. We then hold the engineat that level for a few seconds before running it back down at thesame rate.” The sequence is repeated several times, and at the endof each run, the engineers have to make sure that the test findingsare both plausible and analyzable. “If the results are all in order, wecan use them for the certification report. If not, we have to repeat therun.” For temperature measurements, on the other hand, the enginemust be run up rapidly to various speeds, held at these speeds forsome time, and then decelerated rapidly again. This is why these teststake correspondingly longer.

The airworthiness authorities stipulate that turbines must run at over-speed during stress testing. The design speed equates to 100 per-cent, and the engine will usually run at 90 to 100 percent of this dur-ing normal operation. “Test conditions must be as realistic as possi-ble, and should reflect the environment within a normal production

Highest precision is a must: Fitting of the instrumentation alone takes four weeks.

The PurePower® PW1524G geared turbofan.

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Customers + Partners

New structures,new opportunities

hanging realities, such as new global threat scenarios and ever-decreasing financial resources, have prompted the Federal Republicof Germany to completely revamp its armed forces. Major elements

of this structural reform include downsizing of the Bundeswehr and abolitionof compulsory military service; new mission profiles for the army, air forceand navy; base closures and unit disbandments. Army aviation units are tokeep just three of their seven bases, while the air force will retain seven ofits current twelve wings. Erding air force base, a traditional military installa-tion and home to an MTU facility, is to be drastically reduced in size. How-ever, there is some good news: MTU’s Erding facility will remain untouchedand will continue to look after military engines as part of MTU’s cooperationwith the German air force.

It’s a done deal: Germany’s Bundeswehr is to be completely restructured.Naturally, this will have an impact on the businesses involved in the defenseindustry—among them MTU Aero Engines, which is the German armed forces’lead industrial partner for almost every type of aircraft engine operated bythe services.

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By Martina Vollmuth

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Customers + Partners

Mr. Schreyögg, to what extent will MTU be affected by theBundeswehr reform? As a result of the cuts in systems and flying hours, MTUwill be doing less MRO work for the German armed forces,so business will go down. We’re prepared for this down-turn and have already reduced our capacities to the lowerworkload levels. Things will only become critical if we endup having to look after very small fleets for lengthy peri-ods of time. Take the Tiger combat helicopter, for example;the government is now mulling to procure only half of thequantity originally planned. Such a significant reductionin volume would considerably increase the cost of spareparts provisioning, as well as of the technical expertise tosupport the engines, and would therefore push the oper-ational costs per unit through the roof.

Another aspect to consider is new engine development.To date we’ve been able to continuously expand our know-how thanks to the Eurofighter/Typhoon and A400M pro-grams, but now there are no new projects on the horizonand therefore there’s a lack of fresh impetus for militaryengines of the future, and hence also for commercial en-gines. I believe there is a need for urgent action in thisregard, and share the views expressed by the affectedunits. A military aviation technology program could closethe gap and safeguard and enhance expertise in this field.

Has MTU already begun to adapt to the new situation?We started making adjustments to our capacities twoyears ago, in close consultation with the customer. Welooked at both direct and indirect functions, and themeasures we took included reductions through naturalattrition and transfer of personnel to other positions. Thatprocess is now complete. We also launched our Knowl-edge Management project to make sure our expertise isretained: All the experience we’ve gained working on thevarious military engines we’ve handled over the past fewdecades is currently being captured in a database.

Do you see any new opportunities for MTU?Given the massive organizational changes, if we’re to finda cost-effective way of looking after the systems operatedby the German armed forces, we’re going to have to workeven more closely with the customer to further optimizeour processes. We’re already developing ideas and ourjoint work is progressing well. The feedback has been ex-tremely positive, encouraging us to keep going alongthese lines.

The armed forces in other countries are also facing budgetcuts. Where do you still see growth areas for your businessin the short and medium term?The future of our military programs lies in the export mar-ket. The Eurofighter/Typhoon, Tiger, Sikorsky CH-53K andA400M are all highly advanced systems that place us in

a strong position. More calls to tender are being issuednow than ever before, which is a good sign. The Euro-fighter/Typhoon and its EJ200 engine are attracting thegreatest interest; in that respect we’re ideally positioned.Arguments in favor of the Typhoon include good experi-ence with its operational performance in the Libyan con-flict. However, India’s combat jet tender provided ampleproof that a technically outstanding aircraft is essential,but not in itself sufficient to bag a contract—what’s alsoneeded to convince the customer is strong political sup-port.

How will future engines differ from those of today, andwhat implications will this have for MTU?The powerplant for the A400M is already a next-genera-tion engine: The TP400-D6 is the world’s most advancedturboprop engine. What makes it stand out are its ex-tremely high power density and highly complex controland monitoring system—two features that every futureengine will boast. For MTU, this means that in future we’llbe required to master not only all the mechanics, but alsoa ‘flying Internet’, such as the A400M with its highly inte-grated, extremely complex digital control systems.

To build and support military engines, we need a compre-hensive technology program. Not only to ensure that we’retechnologically prepared for the engines beyond the year2025, but also see to it that our engineers and expertshave the necessary know-how to continue looking afterand further developing today’s systems.

Do you believe that MTU’s military engine business has asecure future for the long term?Of course! And I say that not just because I’m an optimist,but because I know precisely what we’re doing and whatwe have to offer: decades of experience, top-notch prod-ucts and services, and an extremely competent, motivatedteam in all areas of our organization—engineering, pro-duction, MRO and program management. It’s a compell-ing mix, not only for the German armed forces, but alsofor our export customers. I’m firmly convinced we cancontinue to build on our current position, and that’s exact-ly what we intend to do.

The A400M airlifter is powered by four TP400-D6 engines, the Western world’smost powerful turboprop.

The RB199 powering the Tornado is maintained incooperation with the German air force.

Michael Schreyögg, Senior Vice President, Defense Programs

Michael Schreyögg was appointed SeniorVice President, Defense Programs at MTUin 2008. REPORT asked him about the im-plications the reform of the German armedforces has for the company, and what op-portunities it might bring for the future.

Despite the severe cuts, the reform of the Bundeswehr stillaffords certain opportunities for industry. The revised missionprofiles, with operations extending far beyond Germany’snational borders, will give rise to new equipment require-ments such as transportation vehicles. Extremely harsh cli-matic conditions, like the heat and aridity in Afghanistan, forexample, will necessitate new military hardware and speciallyadapted support profiles. And it is also possible that industrialpartners take on responsibility for more extensive servicepackages than before, to relieve the burden on the troopsand allow them to concentrate more on their core tasks.

Faced with shrinking national markets, European industry isnow increasingly looking to other regions of the world. Majorexport campaigns are under way to help sell high-tech prod-

ucts, such as the Eurofighter/Typhoon and the AirbusA400M military transport aircraft, to other nations. MTU fullysupports these endeavors, but is also taking initiatives on itsown—and successfully, at that: The company has already bro-ken into the U.S. military market, and has gained a footholdin Saudi Arabia.

For additional information, contactMichael Schreyögg+49 89 1489-4766

For interesting multimedia services associated with this article, go towww.mtu.de/report

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Customers + Partners

Knights in red-and-white

armor

t is often a matter of seconds. To save victims of roadaccidents or heart attacks, especially in remote or rurallocations, both the patient and the rescuers have to

fight against time. One notable tragic case was that ofeight-year-old Björn Steiger, who died in 1969 as theresult of a road accident—because it took too long for theambulance to arrive. His parents set up a foundation in hisname that has revolutionized rescue services in Germany.Thanks to their initiative, rescue operations have been ac-celerated, emergency call stations have been installed,and the overall quality of rescue services has been im-proved. The first ADAC rescue helicopter took off in1972, and in the same year the predecessor to today’sDRF Luftrettung, Deutsche Rettungsflugwacht e.V., wasfounded. One year later, the new air rescue organizationstarted operations in the Stuttgart region, with a singlehelicopter.

The ADAC automobile association and DRF Luftrettungare the largest air rescue operators in Germany to thisday. DRF Luftrettung alone operates more than 50 heli-copters. In 2011, the distinctive red-and-white helicop-ters clocked up more than 38,000 missions. “The EC135is the rescue helicopter par excellence, enabling us totransport emergency physicians to the scene of an acci-dent as fast as possible,” says Jürgen Zoller, DRF Luftret-tung’s Director Technical Operations.

The air rescue teams of DRF Luftrettung have total confi-dence in their “battle horse”: the EC135 helicopter equippedwith robust, powerful Pratt & Whitney PW200 engines. Theperfect combination for the job, say experts. And that’s justas well, given that in an emergency help must arrive as quick-ly as possible. It sounds simple, but in fact demands a hugelogistics effort—and above all engines capable of standingup to the strain.

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By Daniel Hautmann

The DRF Luftrettung helicopters are stationed at 28 basesin Germany, plus two in Austria and one in Denmark.Each crew consists of one or two pilots, one paramedicand one emergency physician. Most of the physicians areregular hospital doctors, while the pilots, paramedics andtechnicians form part of the permanent DRF Luftrettungworkforce. In total, some 1,000 specialists work for theorganization. And their number is steadily rising to meetthe growing demand for air ambulance services—not be-cause the number of road accidents is increasing (on thecontrary, it is declining), but mainly as a result of struc-tural reforms in the German health care system. Zollerexplains: “There is a growing tendency to concentratefacilities for specific medical conditions in a limited num-ber of clinics. Consequently, we have to transfer inten-sive-care patients from one hospital to another more fre-quently.”

As a result, high demands are placed on the means oftransportation. That is why DRF Luftrettung has chosenPratt & Whitney engines for its helicopters. “The combi-nation of PW206B2 engines and the EC135, in our esti-mation, is a very reliable, ideally suited solution,” accord-ing to Clemens Linden, General Manager of Pratt &Whitney Canada Customer Service Centre Europe (CSC)

Customers + Partners

in Ludwigsfelde, near Berlin. CSC, a joint venture of MTUMaintenance Berlin-Brandenburg and Pratt & WhitneyCanada, is responsible for the fleet management pro-gram (FMP) and the maintenance of the operator’s 34engines. CSC also decides when each engine is to under-go overhaul. Says Linden: “It is part of our job to ensurethat there is never more than one engine in the shop forrepairs, maintenance or overhaul.”

MTU has been working for DRF Luftrettung since 1999 onthe basis of power-by-the-hour contracts, in other wordsagreements in which the customer pays for a fixed vol-ume of maintenance services on the basis of the numberof hours flown. The composition of these services isdecided at the discretion of the customer. This results ingreater cost transparency, and as Linden explains: “We tryto work out the best possible solution in collaboration withour customers. The longer a helicopter engine remains inservice, the better.” This approach has enabled the timebetween overhauls (TBO) to be increased from 3,500 to4,000 cycles. As a result, the customer can fly the enginefor an additional 500 cycles before its next scheduledshop visit, extending the helicopter’s mission availability.The two companies have signed a contract renewing theircooperation agreement through to 2024.

The PW200 engine family was introduced in 1990 forhelicopter applications. More than 2,600 engines indifferent power classes have been produced since thisfamily entered service. The engine is frequently cho-sen to power EC135 helicopters. This Eurocoptermodel is in service in Germany with DRF Luftrettung,ADAC, the federal police forces, the armed forces, andwith numerous air rescue organizations in other coun-tries.

PW200

“Air rescue operations as a rule involve repetitive shortflights,” says Zoller. A helicopter clocks up an average of4.5 cycles per flight hour. This considerably increases thethermodynamic load, and takes its toll on airframe andengines. Zoller explains: “The repeated heating and cool-ing accelerates material fatigue.” Line maintenance, whichincludes minor inspections after specific number of flighthours and the correction of minor helicopter malfunctions,takes place directly at the bases. In the operations centerat Karlsruhe/Baden-Baden airport, 60 DRF Luftrettungtechnicians take care of the helicopters in eleven docks,performing 400- and 800-hour inspections, replacingcomponents or engines, and carrying out other mainte-nance work.

When the 109-kilogram engines need to be overhauled,they are sent to MTU Maintenance Berlin-Brandenburg in

For additional information, contactClemens Linden+49 3378 824-801

Ludwigsfelde, where Jan Bierkamp is in charge of themaintenance work: “We disassemble the engines, cleanthem, and carry out visual inspection followed by crackinspection. We then decide which parts can be repairedand which have to be replaced.” During visual inspectionat the latest, the MTU employees can tell in which envi-ronment the engine has been operated. Air rescue heli-copters often take off and land on meadows, ploughedfields or dusty roads. This is evidenced by foreign-objectdamage (FOD) to the blades—caused by tiny stones thathave been ingested into the engine from the ground. TheMTU technicians are rarely able to restore these parts bymeans of buildup welding or blending. “The high levels ofstress to which these engines are subjected cause wear-related damage relatively quickly,” says Bierkamp.

Rescue helicopters frequently suffer a loss of power dueto elevated engine temperatures. If certain operating lim-its are exceeded, the engines must be overhauled torecover lost performance. To extend the interval betweensuch interventions, the overhaul teams rely on the localservices of the DRF Luftrettung technicians. Lindenexplains: “There are a lot of maintenance tasks that thecustomer’s staff can handle on their own. We provide asmuch support as we can, and everyone is happy with thisarrangement, which works very well.” Both DRF Luftret-tung and MTU benefit from the partnership, as do thepatients—which is even more important because everysecond counts when there’s a life to save.

The specialists at MTU Maintenance Berlin-Brandenburg make sure the PW200 engines are in perfect working condition at all times.

Air ambulances can reach the scene of road accidents quickly and thus help save lives.

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Technology + Science

Taking off with

sustainable fuelAt first glance, the Lufthansa A321 with registration D-AIDG did notappear to be anything out of the ordinary. Only the stickers next to itscabin doors, reading “Powered by Pure Sky sky friendly energy”, andthe slogan on the nacelles of its V2500 engines gave an indication ofits special mission: Between July and December 2011, the aircraft,whose call sign is Delta Golf, was the most important test vehicle everused for investigations into the suitability of biosynthetic kerosene onregular flight operations. And MTU lent a helping hand in the evalua-tion of the test results.

By Andreas Spaeth

roject Manager Joachim Buse, Vice President, Aviation Bio-fuel, at Lufthansa was pleased with the results: “The trialswent extremely well.” Over the test period, the almost

brand-new Airbus A321 served the Hamburg-Frankfurt route upto four times daily. In all, the aircraft accumulated 1,187 flights,sometimes completing as many as eight trips a day. One of theaircraft’s two engines—engine number 2, on the right-hand side—was powered by a mix of biosynthetic kerosene and standard jetfuel. “Previously, biofuel had only been used for ground runs byengine manufacturers and on a handful of test flights,” saysBuse. According to initial calculations, emissions of the green-house gas carbon dioxide (CO2) were reduced by 1,471 metrictons. The total consumption of the biokerosene mix amounted to1,556 metric tons. So far, biofuel has been approved for use onaircraft only if mixed half and half with regular Jet A-1 fuel. Thefuels can be blended without any problems; technical modifica-tions to the aircraft, engine or to the ground infrastructure arenot required.

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The six-month test of biofuel on regular domestic flights wasconducted under Germany’s aviation research program. Forthe tests, the German government provided funds to the tuneof 2.5 million euros, and Lufthansa contributed around fourmillion euros. The burnFAIR tests, as they were called, werecarried out as part of the FAIR (Future Aircraft Research)project, which involves EADS, Airbus, MTU Aero Engines andnumerous research institutes alongside Lufthansa. FAIR waslaunched to examine alternative solutions to replace standardaviation fuel long-term. Among the options investigated also

Technology + Science

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are electric engines. The use of biosynthetic fuel promises tomake a substantial contribution towards achieving the ambi-tious target set by the International Air Transport Association(IATA), which is to halve CO2 emission levels caused by airtraffic by 2050, compared with 2005 levels. The primary aimof burnFAIR is to gain experience in the use of biofuel on air-craft and engines and collect long-term data. Biofuels reduceharmful emissions because the CO2 released when the fuel isburnt has previously been extracted from the atmospherethrough photosynthesis during biomass growth.

By the middle of this year, MTU MaintenanceHannover will be one of the first engine maintenanceproviders in the world to have the technical capabil-ity to conduct acceptance tests using biokerosene.“We are among the pioneers in this field,” says PeterHarster, Director, Industrial Engineering at MTU Main-tenance Hannover. “By then, our two test cells inHannover will be ready to run on biofuel.” Every year,some 500 engines are subjected to test runs of sev-eral hours at this MTU location: “So we’re readywhen our customers are. We expect to offer enginetests with biofuel once 30 percent of our customershave opted to use it to power engines. We need totest these engines, too, under conditions that reflectactual operations as accurately as possible.” An-other reason for using biokerosene is that it cutsCO2 emissions; for plans are to also include test bedruns in the Emissions Trading Scheme in future.

MTU test bedsready forbiokerosene

New Aircraft Concepts30% efficiency improvement*

Advanced Air Traffic Management20% efficiency improvement*

Alternative Fuels80% carbon-free fuel*

* by 2050 as compared with 2000 levels

New Engines50% efficiency improvement*

Future Development of Air Traffic and CO2 EmissionsRe

lativ

e C

hang

e

2000 2010 2020 2030 2040 2050

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4

3

2

1

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Air traffic(+5% p.a.)

CO2 emissions, innovative technologies

CO2 emissions, business as usual(2% p.a.)

Under the burnFAIR project, MTU analyzed the in-flight be-havior of the engines, the aim being to identify any potentialproblems early on. “Many of our customers already rely onour monitoring system,” says Dr. Jörg Sieber, Senior Consul-tant, Innovation Management at MTU in Munich. “It works likethis: We input an engine’s in-flight operating condition data,such as flight velocity and pressure ratio, into a theoreticalengine model and then compare the parameters calculatedusing this model with actual measurement values. This way,we quickly see if things start to go wrong.” In the case of theDelta Golf test Airbus, both engines were calibrated beforethe trials started so that even minimum differences in enginebehavior would be detectable during the tests. “But thereweren’t any differences,” reports Sieber, “except for one:Biofuel has a higher energy density, so consumption was onepercent lower. That’s a very important finding for the aviationindustry.”

Getting hold of the 800 metric tons of biofuel needed for thetests—“the largest quantity ever produced anywhere in theworld,” according to Buse—was a challenge in itself. A Finnishrefinery produced the fuel, using hydrotreated vegetable oil(HVO) made from 80 percent camelina oil from the UnitedStates and 15 percent jatropha oil from Indonesia, plus fivepercent slaughterhouse waste from Finland. “Our fuel is sus-tainably sourced; no rainforests are being destroyed to pro-duce it, and our licensed suppliers have to demonstrate thattheir operations are sustainable,” explains the Lufthansa pro-ject manager. Compliance with requirements like these willbe a prerequisite for the introduction of biofuels into flightoperations on a permanent basis. For now, the Lufthansa tri-als have shown that, from a technical point of view, biofuelsare a viable option.

Although biokerosene is currently more expensive than fossilfuels, the industry anticipates that this will change in themedium term as production volumes increase, and assumingthat the cost of kerosene remains at its current high level.One thing is for sure: The demand for biofuels will grow, notleast because aviation was included in the European Union’sEmissions Trading System at the beginning of 2012. By 2050,biofuels are expected to play a significant role, their share inoverall global air transport fuels being estimated at between30 and 85 percent by that time. Many questions are still un-answered, the most important one being how to produceenough biomass from sustainable sources without compet-ing with the production of food, and without damaging ordestroying vast stretches of land. This much is clear: “Wewant to introduce biokerosene on scheduled flights as soonas possible. But we’ll have to wait at least three to fouryears—that’s the time the plants will take to grow,” says Buse.

Biofuels can do the job: The V2500s powering the Lufthansa A321 performed without a hiccup during the biofuel test phase.

MTU’s Hannover facility is prepared to offer engine tests runon biofuel.

For additional information, contactDr. Jörg Sieber+49 89 1489-2513

For interesting multimedia services associated with this article, go towww.mtu.de/report

Technology + Science

The ultimatein precisionPrecise electrochemical machining (PECM) saves costs andimproves product quality. MTU Aero Engines has refined amanufacturing process that is vastly superior to conventionalelectrochemical machining (ECM). PECM is used to producevery thin, highly twisted high-pressure compressor airfoils. Theexperts at Germany’s leading engine manufacturer are alreadyplanning to extend the use of PECM to other applications.

By Denis Dilba

t every stage of their evolution, engines are expected tobecome a good deal more efficient and at the same timecleaner and quieter. Key to achieving this goal is the com-

pressor, which has to withstand increasingly higher tempera-tures and mechanical loads. To make sure the component cancope with the extreme stresses, today’s high-pressure compres-sors are manufactured in blisk construction from high-tempera-ture nickel-base alloys. The drawback of these materials: “Unfor-tunately, high-temperature alloys can no longer be machinedand processed in a cost-effective manner,” explains MartinBußmann, Senior Manager, Production Engineering/ProcessChains at MTU Aero Engines in Munich. “As these materials aredifficult to machine and, above all, to mill, they cause the toolsused to wear down rapidly. This runs up costs tremendously. Thefact that there is a marked trend towards the increased use ofintegrally bladed compressor disks, which permit higher pres-sure ratios to be achieved with fewer stages, does not makethings easier. Increased performance combined with reducedweight is the name of the game.”

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The experts at MTU are rising to this chal-lenge. “To be able to manufacture high-pres-sure compressor blisks from nickel-base al-loys, we had to find a viable, cost-effectivealternative to milling,” says Bußmann. SoMTU’s team came up with the idea of usingthe precise electrochemical machining pro-cess, which is now being matured for pro-duction. The advantage it affords over con-ventional machining: The tools do not actual-ly touch the workpiece, so they do not sufferwear in the process.

“The basic principle underlying ECM andPECM is the selective removal of metallicmaterials by anodic dissolution using electriccurrent and an electrolyte,” explains AlbinPlatz, MTU expert for electrochemical pro-

For additional information, contactMartin Bußmann+49 89 1489-4703

For interesting multimedia services associated with this article, go towww.mtu.de/report

Workpiece Workpiece

Cathode

Cathode

Continuous feed

Electrolyte

DC voltage10-25 V

Pulsed DC voltage10-25 V

ElectrolyteStream lines Stream lines

Pulsed feed

ECM PECM

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cesses in blisk production. “The material tobe processed is charged positively (anode),while the three-dimensional tool (electrode),which determines the desired shape, ischarged negatively (cathode). In the PECMprocess, the shape of the cathode is analmost exact mirror image of the blisk airfoilto be produced.” An aqueous sodium nitratesolution is used as the electrolyte, whichflows between the anode and cathode. Theelectrolyte serves three functions: It estab-lishes an electrically conductive connection,carries away the removed material and thehydrogen produced by the process, andensures the necessary cooling. As comparedwith the conventional ECM process, PECMachieves significantly higher dimensionalaccuracies, since the working gaps are ex-tremely narrow. As the electrolyte flow isinterrupted at gap widths in the micrometerrange, the gap has to be mechanically open-ed after each short voltage pulse applied todissolve the material. This happens at a fre-quency of up to 50 hertz.

Rough machining of a turned disk geometryto cut out the spaces between what will be-come the airfoils is performed using theestablished ECM process. In a purpose-builtPECM machine, the airfoil-shaped tools (cath-odes) are positioned close to their rough-machined counterparts to produce the airfoilcontour including the annulus surfaces. “Asthe gap between the cathode and the work-piece is narrowing, the electrical resistancedecreases to its minimum while the flow of

electric current reaches its maximum. Theresult is a self-adjusting material dissolutionprocess that produces the desired shapemore or less automatically,” says Platz. Theremoved material is largely converted intometal hydroxide, which is separated from theelectrolyte using filters. In electrochemicalmachining, the material removal rate de-pends on the machining angle, so that themachining results obtained for the airfoil lead-ing and trailing edges are less satisfactory.The bigger the working gap used, the greaterthe differences along the machined contour.With PECM, these differences are minimizedthrough extremely small working gaps. As aresult, the PECM process on the whole per-mits the delicate edge geometry of compres-sor airfoils to be machined very precisely andproduces a mirror surface finish.

“The results obtained with PECM on integrallybladed compressor disks made from nickel-base alloys are outstanding,” according toPaul Bünger, Senior Manager, Electrochemi-cal Processes at MTU. The findings havemeanwhile been presented to industry pro-fessionals and have drawn considerable at-tention—not least thanks to the economicadvantages the technique affords over con-ventional machining: shorter machining times,significantly lower tool costs, and minimumpost-processing of the surfaces.

But that’s not the end of it: The process,which will be used in the production of blisksfor the engine to power the A320neo, offers

even wider potential. While it is true that theelectrochemical removal process is currentlyno faster than milling, Platz believes that itcan be further improved for greater economicbenefits in future. MTU is already exploringother applications for PECM, as for examplemachining of blades in titanium aluminide. Inthis effort, the company cooperates withProfessor Ewald Werner, who chairs theInstitute of Materials Science and Mechanicsof Materials at the Technical University ofMunich. Says Werner: “Presently we areworking, for instance, on the automated cal-culation of process parameters for variousmaterials, and on a robust control system forthe PECM process.” The necessary testingcan be performed on a PECM test facilityfinanced by MTU, he adds. “In the long term,we plan to use PECM more widely as a man-ufacturing process in engine construction,”explains Bußmann. “MTU is the only companyin the industry that is exploring the use ofPECM in the manufacture of engine parts ona large scale. Given the complexity of thetechnology, this means that we are wellahead of the field—and likely to remain so forquite some time.”

More precise than ECM: The PECM process ensures markedly higher accuracies, since the workinggaps are extremely narrow.

The PECM prototype facility in Munich.

One of the first components manufactured using PECM was a high-pressure compressor test blisk.

A glance into the machine interior: the working zone with shapedelectrodes.

s things stand now, the PW1100G-JM will fea-ture our brush seals at four different loca-tions,” says Project Manager Dr. Stephan

Pröstler, who is responsible for the developmentand design of brush seals for commercial engineprograms at MTU in Munich. “Two seals are fitted inthe compressor, and two in the turbine. ThePW1217G for the Mitsubishi Regional Jet and thePW1524G for the Bombardier CSeries—another twomembers of the PurePower engine family—both havethree brush seals.”

On the PW1100G-JM, MTU’s products replace con-ventional labyrinth seals. These are contactless shaftseals which make use of fluid dynamic effects. Toseal a gap, say, in the compressor, the shaft andcasing are provided with radial fins which engageinto one another, thus creating an intricate pathwaywith abrupt directional changes. This increases theflow resistance, but does not fully seal the gap. “Bycontrast, brush seals provide a sealing system thatis as effective as it is simple,” explains BenjaminGroßkurth, Senior Manager, Brush Seals at MTU. i

Products + Services

Simple principle, great action

They are reliable, durable and extremely effective,and advanced aircraft engines can hardly do withoutthem. The benefits afforded by MTU’s brush sealshave also won over U.S. manufacturer Pratt &Whitney who uses them in its new PurePower®

PW1100G-JM geared turbofan engine, which willpower the Airbus A320neo. Germany’s leading enginemanufacturer first developed and patented its uniquein-house manufacturing process for these parts backin the early 1980s.

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By Bernd Bundschu

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“Thousands of very thin wires form a highly flexible seal elementwhich continuously adapts to the moving surface to be sealed. As aresult, the gap between the rotor and stator can be reduced to a min-imum. The leakage rate of brush seals is up to 80 percent lower thanthat of labyrinth seals, and their compact design has the addedadvantage that these seals need less space.” Their effectiveness hasalready been demonstrated on the geared turbofan engine for theA320neo: Compared with labyrinth seals, MTU’s seals have halvedthe cooling-air losses at all installation positions. This results in in-creased efficiency and, hence, reduced fuel consumption and lowercarbon dioxide emissions.

What makes MTU’s brush seals so special is that they are made up oftwo distinct components—the seal element and the seal housing.Depending on the intended application, any form of housing can becombined with a variety of seal elements. The seal element is madeup of the core wire, the bristle pack and a clamping tube, while thebrush seal housing includes a support plate and a cover plate. The lat-ter shields the bristles from the incident gas stream, while the formerholds them firmly in place when under pressure. The Munich-basedengine experts devised a unique manufacturing process for their seals,which involves a wire looping and clamping method, and have gradu-ally perfected it over more than two decades. Großkurth explains:

Brush seals are not only suitable for use in engines,they have also found homes in power stations,machine tools and pumps. They reduce leakages ofvarious media, including air, gas, oil, and water. MTUfirst tested brush seals in industrial compressorsand gas turbines back in 1996. Meanwhile, theseseals have become increasingly common also inmore advanced gas and steam turbines, as well as inpumps and on spindles. Brush seals can be used toseal pressure balancing pistons and shroud seg-ments, as well as shafts and bearing chambers ingas turbines. They are readily removable for mainte-nance purposes and are generally easy to retrofit inplace of existing labyrinth seals. MTU’s customersinclude major manufacturers of thermal power sta-tions all over the world.

“We wrap the individual bristles around the core wire and positivelyfix them in place using the clamping tube. This process ensures theyare held securely so that wire losses in operation can virtually be pre-cluded.”

And that is how the brush seal works: to put it in a nutshell, the wiretips that are in contact with the surface compel the incident gas toflow through the roughly two-millimeter thick wire bristle pack. Thegas stream urges the wires against the support plate and causes thewire pack to compact, closing the voids between wires and minimiz-ing the flow through the brush seal. For the various applications, MTUuses different materials to make the bristle pack—even aramid fibers.The pack density depends on the diameter of the wire or fiber select-ed; it varies between 50 and 200 Bpmm (bristles per millimeter of cir-cumferential length) for wires in Haynes alloys, while aramid fibershave a density of either 4,000 or 6,350 Fpmm (fibers per millimeter).What makes aramid fibers stand out is their low weight and superbsealing action. Thanks to their elasticity, the wires or fibers—regard-less of the material used—adjust to accommodate radial as well asaxial rotor excursions, yielding to pressure and returning to their ini-tial position, suffering virtually no wear.

“Depending on where a brush seal is installed in an engine, a one-per-cent saving in cooling air can reduce fuel burn by half a percent ormore,” says Pröstler. “For a medium-haul aircraft, that equates to manytons of fuel each year.” According to measurement and analysisresults brush seals have already proven their worth during testing ofthe PW1217G and PW1524G engines, and they have so far met allexpectations in flight trials as well. On the PW1524G, the two brushseals that replace the labyrinth seals in the turbine will help cut fuelconsumption by up to 0.1 percent. As regards the PW1100-JM, no pre-cise assessment can be made to date, as the test program will notcommence before the third quarter of 2012. Pröstler is pleased toreport that “Pratt & Whitney is obviously satisfied with our seals. Ourcooperation is excellent and based on mutual trust and benefit.”

MTU’s experts in Munich are working relentlessly to further developthe brush seal technology. “We’re using our in-house test facility andare cooperating with a number of universities, among them the Karls-ruhe Institute of Technology (KIT),” says Großkurth. Under nationaland international research projects, MTU is currently investigatingalternative designs, as well as potential new bristle materials andfibers. “Our aim is to replace as many labyrinth seals in engines andindustrial gas turbines with MTU brush seals as possible,” says theMTU expert.

For additional information, contactBenjamin Großkurth+49 89 1489-2709

For interesting multimedia services associated with this article, go towww.mtu.de/report

MTU has developed a unique manufacturing method for brush seals. Brush seals also lend themselves for industrial gas turbineapplications.

To make sure the seal functions perfectly the resilience of the bristlepack is checked prior to installation.

The wire tips are given the final touches.

Versatile seals

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Products + Services

Attention to detail that

paid offExhaust gas temperature (EGT) is, quite literally, a hot topicfor MTU Maintenance and its customers. MTU MaintenanceZhuhai has succeeded in improving the EGT margin of theCFM56-3C1 engine. “The tremendous amount of time andeffort we invested has paid off, for us and especially for ourCFM56-3C1 customers,” said Holger Sindemann. “We’vemanaged to raise the average EGT margin for this enginetype by almost ten percent.”

By Nicole Geffert

indemann, who was MTU Maintenance Zhuhai’sPresident and CEO until April before he becameManaging Director and Senior Vice President of

MTU Maintenance Hannover, had even more good newsto announce: “What’s also very important to us is thatwe’ve been able to improve our EGT margin first passyield (FPY)—that’s the yardstick, or performance indica-tor, by which we measure customer satisfaction. We’veincreased our FPY by more than 20 percent, and we’vealso shortened our turnaround times.” A quick word ofexplanation: An engine’s EGT limit is the maximum tem-perature at which it can operate for a limited period oftime without suffering damage, and the EGT margin is thetolerance range between this limit and the actual temper-ature reached in operation. In service, engine perform-ance decreases with age because certain components aresubject to extreme stresses. In a high-pressure turbine,the blades and seal segments are particularly badlyaffected by wear and tear.

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erosion of component surfaces, also have an adverse effecton performance.

“We carried out almost 40 different tests as part of our engineanalysis. For each test we changed just one detail—for exam-ple a setting of the fuel injection nozzles—and then checkedwhat effect it had,” said Landes. This way, the team graduallyaccumulated a store of new and specific information regard-ing which repair measures have a bearing on the EGT margin,and how. Landes believes it should be relatively easy to intro-duce these measures on the shop floor and ensure conform-ity with the relevant documentation. “In our back-to-back testprogram, one of the things we looked at was how the differentgrinding techniques used on the abradable linings of the high-pressure turbine affect engine performance.” Essentially,there are three different grinding methods: center grinding,offset grinding and lobe grinding. Landes goes on: “Expertstend to disagree on which of the three grinding techniquesensures the best engine performance. But thanks to our tests,we were able to determine their various effects and pick theone producing the best performance.” The shop’s internalprocesses were then modified so the proven technique isnow standard practice at MTU Maintenance Zhuhai—to thebenefit of all its customers. The feedback received so far ispositive. As China Postal Airlines confirmed, the EGT marginof the CFM56-3C1s in service with the Chinese cargo carrierwas appreciably higher after the shop visit. China Postal cur-rently operates 17 Boeing 737s and is a regular customer ofthe Zhuhai shop.

As time goes by, the engine gradually becomes less efficientand its combustion temperature rises, so it burns more fuelto produce the same thrust. Its exhaust gas temperature,which is constantly monitored by sensors in the turbine anddisplayed in the cockpit, rises, progressively edging closer toits limit. Eventually, when the EGT margin becomes too small,the engine must be returned to the shop for overhaul. If it isnot, there is an increasing risk that the engine—if subjectedto unfavorable operating conditions—will exceed the limit.Should that happen, the pilot would have to reduce thrust,which would in turn have a detrimental effect on the aircraft’sperformance, that is on its take-off power—and that is simplynot acceptable.

“Since the EGT margin is greatest when an engine is new orhas recently been overhauled, and becomes smaller the longeran engine is in operation, it is a key factor in determiningexpected time on wing,” explained Frank Bodenhage, previ-ously Chief Operating Officer and now the new man at thehelm of MTU Maintenance Zhuhai. The Chinese shop special-izes in the maintenance of V2500 and CFM56 engines, andin 2011 it handled almost 50 CFM56-3C1 units. Bodenhagecontinued: “What our customers expect and what we want toachieve is an excellent EGT margin that will remain stable for

MTU Maintenance Zhuhai, a joint venture ofMTU Aero Engines and China SouthernAirlines, the country’s largest carrier, is thebiggest MRO company for aircraft enginesand also the market leader in this segmentin China.

While the Zhuhai-based maintenance facilityinitially only repaired and overhauled en-gines in service with China Southern, todayalmost half the powerplants it takes care ofare operated by other airlines, be they basedin China, South-East Asia or elsewhere inthe world. Demand is on the rise. HolgerSindemann was pleased to report: “We’recurrently increasing our capacities by 50percent, from 200 to 300 shop visits a year.”In order to further optimize work processes,the maintenance shop is being expanded byan additional 4,500 square meters. The workis already in full swing and it is anticipatedthat the new extension will be inaugurated inmid-2012.

Sindemann added: “These developments putMTU Maintenance Zhuhai in the best possi-ble position to continue benefiting fromChina’s anticipated growth rate of roughly

Flying high

For additional information, contactFrank Bodenhage+86 1382 3050 680

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Products + Services

as long as possible in service. So we looked into options todo still better than we do today.” The team began to collectall the information available on EGT margins within MTU, whichproved to be no mean feat in itself. “Even after we’d siftedthrough it all, we still ended up with a long list of around 60points, some of which were contradictory,” recalled MichaelLandes, Senior Manager, Engineering, at MTU MaintenanceZhuhai.

The team then drew up a best-practice list and decided toverify each individual point before changing any processes inthe shop or introducing new ones. It was at this point that theteam came up with a rather unusual idea. Bodenhage ex-plained: “We bought a used CFM56-3C1 in good conditionand—alongside our day-to-day work—carried out a series oftests and analyses on it over a period of several months inorder to establish precisely which factors affect the EGT mar-gin for this engine type, how they do so, and how we mightimprove the margin for the benefit of our customers.” Theyalso made sure they studied what was going on outside theengine proper, as, for instance, environmental factors. Afterall, it is not only frequent take-offs and landings that stressengine components: Poor environmental conditions such asstirred-up sand, which is ingested into the engine and causes

ten percent a year. If our plans work out asintended, our expanded facilities will be readyat just the right time to allow us to handlemore than 200 shop visits for the very firsttime in 2013. In the medium term, our aim isto make the transition from China’s No. 1 formaintenance to Asia’s No. 1.”

A satisfied MTU customer: China Postal Airlines

A high-pressure compressor is being prepared for high-speed grinding.

A jewel in the MTU Group: MTU Maintenance Zhuhai

TU’s service approach is much appreci-ated by customers. Many airlines, espe-cially in the U.S., are already making

use of the new service, among them JetBlue. Thesuccessful New York-based carrier has for yearsentrusted MTU Maintenance Hannover with themaintenance, repair and overhaul of its entirefleet of V2500s. “We greatly welcome MTU’smove, since it will make on-wing maintenanceavailable faster, and hence easier to plan,” saysDave Ramage, Vice President, Technical Oper-ations at JetBlue. “This way, we can take advan-tage of MTU’s dependable, high-quality servicesas part of a truly comprehensive service pack-age.” MTU Maintenance Dallas engine mechanicshave already come to the carrier’s base at JohnF. Kennedy International Airport in New York anumber of times to work on some of the over 250V2500 engines operated by JetBlue. Needless tosay that they successfully completed their taskseach time.

Global

On-site, on-wingsupport

Last year, MTU took a majority stake in U.S.-based on-siteservice provider Retan Aerospace, thus adding another rep-utable facility to its network of maintenance shops. Throughits newest subsidiary, which has since been renamed MTUMaintenance Dallas, the German engine manufacturer islooking to expand its position in the on-site market by offer-ing an exceptional service. In a next step, MTU is planningto set up a global on-site service network. With this move,MTU underscores its commitment: To provide its customersaround the globe with fast and flexible solutions.

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By Silke Hansen

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Global

MTU Maintenance Dallas has a very strongservice portfolio to offer: from borescope in-spections, to top case repairs and the re-placement of damaged fan blades, throughto the replacement of complete modules orengines on wing. “Our goal is always to helpthe customer quickly and efficiently, directlyon site on the apron or in the hangar if wecan, in order to keep downtimes as short aspossible,” explains Christoph Heck, Vice Pres-ident, Marketing and Sales, The Americas atMTU Maintenance. This holds true both foremergency AOG (aircraft-on-ground) situa-tions and for scheduled maintenance work.

The new facility in Dallas adds a powerfulservice unit to MTU’s worldwide network,one which has specialized in AOG and on-siteservice for many years and has earned anexcellent reputation in the aviation commu-nity. Last year alone, the team was called out150 times. And this number is expected torise even further as airlines are increasinglyasking for engines to be maintained or re-paired on wing. That saves them time andmoney, since grounded aircraft are extremelycostly. “MTU Maintenance Dallas allows us toprovide this much sought-after on-site sup-port service for all of our product lines, whichfurther improves on-wing times for our cus-tomers,” explains Christine Schweikl, Direc-tor, On-Site Service at MTU Maintenance.

MTU’s broad engine portfolio, which includesthe CF34, CFM56, V2500, PW2000, CF6 andGE90, covers every type of aircraft from busi-ness jets to long-haul aircraft. The rapid-res-ponse team in Dallas is available 24 hours aday, 365 days a year to serve the needs ofcustomers wherever in the world they may be.Before mechanics are allowed to performwork and issue certificates covering the workperformed on a customer’s engine they nor-mally need the approval of the local aviationauthorities. Since MTU Maintenance is in thefortunate position of holding all the neces-sary certificates worldwide, the company canrespond quickly and flexibly also in caseswhere ad-hoc repair services are needed.

“We’re now a one-stop shop for the cus-tomer,” says Heck. Take damage caused bybird strike, for example. In that case, theengine will be subjected to borescope in-spection on site. “If necessary, MTU’s expertscan now rework minor local damage on fanand compressor airfoils using the so-calledboroblending process, which obviates theneed for disassembly so that the engine can

Borescopes permit an engine’s interior to be inspected from outside.

The experts of MTU Maintenance Dallas ensure prompt and flexible service worldwide.

For additional information, contactChristoph Heck+49 511 7806 - 2621

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be returned to service quickly.” If an acciden-tal collision with a bird causes major damagethe engine must be disassembled. MTU’srepair specialists will then remove the enginefrom the aircraft and send it to the nearestMTU shop as quickly as possible. The mainte-nance group has set up a worldwide network,operating shops in Hannover, Ludwigsfelde(near Berlin), Vancouver and Zhuhai. A furtheradvantage is that the customer can be provid-ed with a replacement engine from the com-pany’s engine lease pool. And the MTUPlus

repairs, a number of high-tech repair tech-niques developed in-house, ensure afford-

For module replacement, the engine is removed from the wing.

able solutions. This all-round carefree serv-ice package is called Total Engine Care.

In the North American market, MTU Mainte-nance is now ideally placed to provide on-siteservices to its customer base. It makes goodsense to have a strong presence there, giventhat most of its customers are based in thispart of the world. “For some years now,we’ve been operating a repair station inAppleton, Wisconsin, which primarily servesour major CF34 customer, Air Wisconsin. Thiscollaboration has proved to be a success.Now, thanks to the additional resources

we’ve gained with MTU Maintenance Dallas,we can offer this package of services also toother customers,” explains Schweikl. Butthat’s not the end of the story: “We’re plan-ning to expand the on-site service step-by-step to Europe, Asia and the Middle East bythe end of 2013.”

Report

The silentgiant

Tim Clark can’t stop raving about his “baby”, theEmirates A380. The Dubai-based mega airline’s Pres-ident put his own personal stamp on the aircraft byintroducing some entirely new inflight amenities.Unique to Emirates, for example, are the two onboardshower spas in the First Class cabin. Clark had firstto convince Airbus that the idea was a practicableone. Emirates is the largest A380 customer world-wide. The giant aircraft is also a favorite amongstpassengers—thanks in large part to the quiet GP7000engines, in which MTU has a significant share.

By Andreas Spaeth

he Arab airline has ordered a total of 90super jumbos. It would like to add another30 of the airliners, but its home base is too

small to accommodate this large number ofA380s. The carrier currently has over 20 A380sin operation—and is enjoying great success withthem. “It’s a wonderful aircraft, everybody wantsto fly her. And it wasn’t just a short honeymoonat the beginning: Three years after the first flight,demand is still robust,” Clark is pleased to report.He had never doubted that the A380 would be apopular aircraft, which is why his airline spent somuch time designing the interior, for example.What strikes many passengers on board the A380most is how surprisingly quiet the cabin is. TheEmirates pilots, whose resting area is situated atthe back of the economy cabin on the main deck,weren’t quite so happy with the situation to beginwith. Clark recalls the problem: The GP7000 en-gines were so quiet that the pilots, who sleep withearplugs, were being disturbed by noise comingthrough from the cabin. The issue has since beenresolved by making some changes to the flightcrew rest compartment.

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Report

The worlds biggest passenger aircraft stops over in Munich: An A380 operated by Emirates at Franz-Josef-Strauss Airport.

The low-pressure turbines of the GP7000 are assembled at MTU in Munich.

On the ground, too, an A380 only generates about half asmuch noise as a Boeing 747 on average. This is particu-larly important for airports served by large numbers ofA380s, as, for example, London Heathrow, Dubai, Sin-gapore and, more recently, Frankfurt. This low noise levelis largely attributable to the quiet engines. Emirates is

the biggest customer for the Engine Alliance GP7000, inwhich MTU Aero Engines holds a stake of 22.5 percent.“The requirements Airbus set for noise emission levels inparticular were incredibly tough,” recalls WolfgangGärtner, GP7000 Program Director at Germany’s leadingengine manufacturer in Munich. MTU is responsible for

the development and assembly of the low-pressure tur-bine and the turbine center frame, and also manufac-tures components for the high-pressure turbine. “Almosta third of the metal that goes into a GP7000 passesthrough our hands,” says Gärtner.

June 2011 saw the GP7000 reach an important mile-stone: 500,000 flight hours on commercial A380 flights;August 1, 2011 marked the third anniversary of its inau-gural flight with Emirates. At the time, the carrier alreadyhad 15 of the double-deck aircraft in its fleet. The GP7000engines had proven to be highly fuel efficient and ex-tremely quiet, said Sheikh Ahmed Bin Saeed Al-Maktoum,Chairman and Chief Executive of the Emirates AirlineGroup. In its first three years, the Emirates A380 fleetclocked up 117,786 flight hours carrying 5.92 millionpassengers over 91.96 million kilometers—an impressiveset of statistics. Emirates is not the only airline to haveopted for the GP7000; Air France and Korean Air alsopower their A380 fleets with these engines.

The Emirates fleet is expanding at a fast pace: “By March2013, we will have 53 aircraft in service, and the last ofthe 90 aircraft we’ve ordered comes in November 2017,”announces Clark. All of them will be powered by GP7000engines, which spells a lot of work for MTU and its part-ners. Emirates has been operating daily A380 flights toMunich since late 2011. The Munich airport is very close tothe MTU factory that produces important components ofthe super jumbo’s engines. As Thierry Antinori, Emirates’Executive Vice President, Passenger Sales Worldwide,made sure to point out during celebrations for the firstflight on the Munich route, Emirates made a deliberatedecision to choose an MTU engine.

Emirates now has plans to fly the A380 on routes to almostall continents. ”Just to serve twelve destinations likeSydney, New York, San Francisco and São Paulo doubledaily I’ve got 20 aircraft taken out straight away, then 60for Australia/New Zealand and North and South America.But I only have 90 aircraft on order. What does this tellyou? I need more!” The only constraint is a shortage ofspace at Dubai airport to park these extra aircraft. Theairline would also be interested in the A380-900, whichwould have a seating capacity of more than 489 peoplein a three-class configuration. “I would need it todayserving Paris or Heathrow, fitting in 750 passengers in atwo-class cabin,” says Clark. The engines themselveswouldn’t be the problem: ”The GP7000 can meet therequirements of an A380-900 just as easily,” confirmsGärtner.

42 43

For additional information, contactWolfgang Gärtner+49 89 1489-2803

For interesting multimedia services associated with this article, go towww.mtu.de/report

Even though the A380 is some 180 metric tons heavier thanthe Boeing 747, and the GP7000 has to provide the extrathrust needed to lift that additional weight, the A380 gener-ates at least 50 percent less noise on take-off and landingthan the jumbo jet. The A380 has to meet such strict noiseemission requirements to be allowed, for example, to takeoff and land at certain times of the day at London Heathrow.

Quiet engines thanks toinnovative technology

Meeting the specifications presented a huge challenge to itsdesigners, among them Paul Traub, physicist and aeroa-coustics expert at MTU in Munich. The low-pressure turbine(LPT) developed by MTU must satisfy exacting demands:“The LPT has to perform equally well at both high and lowengine speeds; yet any acoustic design measures taken maynot compromise aerodynamic efficiency.” The key acousticfeature of the low-pressure turbine is the cut-off design inthe rear three of six turbine stages, which is effective at highand low speeds. As a result of the rotor-stator interaction inthe aft stages the sound waves produced cannot propagate,that is, they are cut off. “The sound wave thus peters out inthe flow duct and fades away substantially,” Traub explains.This effect is attributable also to the low flow velocity of theair exiting the turbine. “Overall, the contribution of the turbineto the total noise produced must be kept at a minimum.”

After: The cut-off design effectively minimizes soundwaves propagation.

Before: The sound waves can propagate freely.

4544

In Brief

South Korean carrier Asiana Airlines and USAirways have both selected MTU MaintenanceHannover to provide maintenance, repair andoverhaul (MRO) services for their CF6-80C2engines. By winning the contract from AsianaMTU Maintenance has succeeded in entering theSouth Korean market. Asiana is among the lead-ing airlines in Asia and currently operates a mixedfleet of 72 Boeing and Airbus aircraft. US Air-ways has entrusted the Hannover shop with themaintenance of its engines since 1993—then stilloperating as America West Airlines.

An endowed professorship at theUniversity of Stuttgart has been setup to conduct research work into newaircraft engine designs, the aim beingto improve structural reliability. MTUwill fund the new professorship forstructural mechanics in aircraft en-gines at the university’s Institute ofAeronautical Propulsion Systems for amaximum of 20 years, making a totalcontribution of over 2.8 million euros.MTU COO Dr. Rainer Martens said:“The creation of this professorship willhelp us find solutions to current prob-lems in the fields of mechanical engi-neering and new materials for futureaircraft engines. Students and youngprofessionals will be optimally pre-pared for the challenges they will haveto tackle in their future professionaloccupations.”

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Contributions credited to authors do not neces-sarily reflect the opinion of the editors. We willnot be held responsible for unsolicited material.Reprinting of contributions is subject to the editors’ approval.

Masthead

EditorMTU Aero Engines Holding AGEckhard ZangerSenior Vice President Corporate Communicationsand Public Affairs

Managing editorTorunn SieglerTel. +49 89 1489-6626Fax +49 89 1489-4303torunn.siegler@mtu.de

Editor in chiefMartina VollmuthTel. +49 89 1489-5333Fax +49 89 1489-8757martina.vollmuth@mtu.de

AddressMTU Aero Engines Holding AG Dachauer Straße 66580995 Munich • Germanywww.mtu.de

RealizationHeidrun Moll

Editorial staffBernd Bundschu, Denis Dilba, Nicole Geffert, Silke Hansen, Daniel Hautmann, Patrick Hoeveler,Odilo Mühling, Andreas Spaeth, Martina Vollmuth

LayoutManfred Deckert Sollnerstraße 73 81479 Munich • Germany

MTU Aero EnginesAndreas Spaeth; Eurofighter; MTU Aero EnginesAirbus; MTU Aero EnginesBombardier; Airbus; MTU Aero EnginesEurofighter; EADS; MTU Aero EnginesDRF Luftrettung; MTU Aero EnginesLufthansa; Airbus; MTU Aero EnginesMTU Aero EnginesSiemens press picture; MTU Aero Engines China Postal Airlines; MTU Aero Engines JetBlue Airways; MTU Aero EnginesAndreas Spaeth; Flughafen MünchenGmbH; MTU Aero EnginesAsiana Airlines; MTU Aero Engines

Photo creditsCover Page:Pages 2–3

Pages 4–5Pages 6–9

Pages 12–15

Pages 16–19Pages 20–23

Pages 24–27Pages 28–31

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Pages 36–39Pages 40–43

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CF6: New MRO contracts

MTU sponsorsnew professorship

Holger Sindemann has been appointed Managing Directorand Senior Vice President of MTU Maintenance Hannoverin Langenhagen, effective May 1. Sindemann, who had ledMTU’s Chinese location for four years before, takes overfrom Dr. Martin Funk. His successor as President and CEOof MTU Maintenance Zhuhai is Frank Bodenhage, who hadbeen the shop’s Chief Operating Officer for six years. MTUMaintenance Hannover is the centerpiece of the MTUMaintenance group, and the Chinese location is the com-pany’s largest operation outside Germany.

Cooperation with Avio

New men at the helm of MTU Maintenance Hannoverand MTU Maintenance Zhuhai

MTU Aero Engines and Italian engine manu-facturer Avio S.p.A. will jointly explore themarket potential of propulsion systems forunmanned aerial vehicles. The investigationswill focus on medium-altitude long-haul un-manned aerial systems and unmanned com-bat aerial vehicles (UCAV). A Letter of Intentto this effect was signed in mid-March. MTUCEO Egon Behle said: “This LoI marks a sig-nificant step forward towards our goal ofkeeping our military sector competitive in theface of declining defense budgets and chang-ing requirements regarding the future equip-ment of the armed forces. UAS will play anincreasingly significant role moving forwards,and we want to have an equitable share in thismarket segment.”

Dr. Ottmar Pfänder (EPI), Michael Schreyögg (MTU), Herbert Neumeier (MTU), EPI President Simon Henley,Gerhard Bähr (MTU), MTU CEO Egon Behle, Martin Maltby (EPI), Ian Fitzgerald (MTU), Martin Schäffner (MTU)and Stephanie Gantke-Eiringhaus (MTU) (from left) gave the green light for TP400 production deliveries at MTU Aero Engines in Munich.

MTU COO Dr. Rainer Martens and the Rector of the University of Stuttgart, Professor Wolf-ram Ressel, signed the cooperation agreement.

EPI Europrop International started deliveries of TP400-D6 production engines final assembledat MTU in Munich in mid-April. The first units will power the French Air Force’s first A400Mmilitary airlifter, which is slated to enter service early next year. All production engines areassembled at MTU Aero Engines in Munich from modules produced by MTU and the otherthree partners in the EPI consortium ITP, Rolls-Royce, and Snecma. The engines are then sub-jected to acceptance testing at MTU Maintenance Berlin-Brandenburg before they are shippedto the Airbus A400M final assembly line in Seville.

TP400-D6 deliveries started MTU on track for continued growth MTU Aero Engines Holding fully achieved itsforecast for the financial year 2011: In lateFebruary, the company announced that rev-enues had increased eight percent, to over 2.9billion euros; adjusted for the effects of theU.S. dollar exchange rate, revenues even rose13 percent. MTU improved its operating profitto 328.0 million euros, the EBIT margin was11.2 percent and the net income (adjusted)grew to 196.6 million euros. MTU CEO Egon

MTU Aero EnginesRevenues

of which OEM businessof which commercial engine businessof which military engine business

of which commercial MRO businessEBIT (calculated on a comparable basis)*

of which OEM business*of which commercial MRO business*

EBIT margin (calculated on a comparable basis)for OEM business*for commercial MRO business*

Net income (calculated on a comparablebasis), old definitionNet income (calculated on a comparablebasis), new definition**Earnings per share (undiluted), reportedFree cash flowResearch and development expenditure

of which company-fundedof which outside-funded

Capital expenditure on property, plant andequipment

Order volume (order backlog plus value ofMRO contracts)

of which OEM businessof which commercial MRO business

Employees

20102,707.41,663.51,177.6

485.91,074.0

310.7231.1

78.211.5 %13.9 %

7.3 %182.3

183.8

2.91144.8238.7148.1

90.684.8

Dec. 31, 2010

9,699.1

4,331.55,367.6

7,907

20112,932.11,846.61,401.1

445.51,116.6

328.0237.9

93.111.2 %12.9 %

8.3 %184.1

196.6

3.24129.0261.9165.8

96.1113.7

Dec. 31, 2011

10,537.1

4,776.65,760.5

8,202

Change+ 8.3 %

+ 11.0 %+ 19.0 %

- 8.3 %+ 4.0 %+ 5.6 %+ 2.9 %

+ 19.1 %

+ 1.0 %

+ 7.0 %

+ 11.3 %- 10.9 %+ 9.7 %

+ 12.0 %+ 6.1 %

+ 34.1 %

Change

+ 8.6 %

+ 10.3 %+ 7.3 %+ 3.7 %

MTU Aero Engines—key financial data for 2011

(Figures quoted in million €, calculated on a comparablebasis. Statements prepared in accordance with IFRS. Fig-ures calculated on a comparable basis apply adjustmentsto the IFRS consolidated results to exclude the effects ofIFRS purchase accounting)

* In the consolidated financial statements, the profit/loss of companies accounted for using the equity method and the profit/loss of companiesaccounted for at cost are no longer included in the financial result. Instead, for the sake of clarity, these two items are now recognized in EBIT.

** As in the past, net income adjusted reflects adjustments made to eliminate the effects of the purchase price allocation and the effects of the financial result that have no impact on the company’s operating performance. These effects include measurements at the balance sheet date,such as the value of U.S. dollar cash holdings and fair value measurements of derivatives and nickel holdings. The standardized tax rate applied is unchanged at 32.6 %.

Behle was pleased with the results: “In 2011,we achieved all our quantitative targets—eventhose that we had revised upward in the courseof the year—thus establishing a sound basis forsustainable and profitable growth,“ he said. Hisgoals for the future are ambitious: “By 2020,we intend to double our annual revenues to sixbillion euros and achieve an EBIT margin of atleast 12 percent.”

MTU provides MRO services for the CF6 enginespowering Asiana Airlines’ Boeing 747 aircraft.

HolgerSindemann

Frank Bodenhage