MRO options older & mature engine types - Aero Norway€¦ · CF6-50 series. A small number of...

AIRCRAFT COMMERCE ISSUE NO. 118 • JUNE/JULY 2018

50 IMAINTENANCE & ENGINEERING

The fleets of older aircraft andengine types are inevitably inconstant decline. The fleet ofolder engine types thereforeimplodes, and so reduces the market formaintaining and repairing them. As aresult, many of the major maintenanceproviders for these engine types leave themarket in favour of pursuing themaintenance market for younger engines.This raises the question of which engineshops are available to airlines to maintainolder engine types.

The main fleets of older narrowbodyaircraft are the MD-80, 737 Classic and757. These are powered by the Pratt &Whitney (PW) JT8D-200; the CFM56-3series; the Rolls-Royce (RR) RB211-535;and the PW2000. The main fleets of olderwidebodies are the 747 Classics and 747-400, the MD-11 and the A300-600/A310-300. These are mainlypowered by the PW4000-94 and CF6-80C2, but also the PW JT9D and theCF6-50 series. A small number of A340-300s are still in operation, powered bythe CFM56-5C, and some A300B2/B4and DC-10 freighters, powered by theCF6-50 series.

Fleet profiles The active fleets of these main

narrowbody and widebody types areabout 38% of the number built. About36% of the active aircraft of these typesare operated as freighters, and more willbe converted to freighters over the nextfew years. This includes the 737 Classicand 757, 747s, MD-11s, A300-600s andA310s, and some DC-10s. Many of thesefreighters operate at relatively low ratesof utilisation, and so accumulate smallnumbers of flight cycles (FCs) per year.

The number of each aircraft typebuilt, and the active number of aircraft inpassenger and freighter configurationwith each engine type, and thecorresponding number of active engines,

and the age range of each type in serviceare summarised (see table, page 52).

The significance of the number inactive service compared to the numberbuilt is that the retirement of a largenumber of aircraft results in acorrespondingly large number of usedand time-continued or ‘green time’engines available on the market. Thissupply of used engines, engine modulesand serviceable or unserviceable material,and engine casings alters the economicsof owning or leasing and maintainingengines. Moreover, the supply of enginesand associated modules or componentsconstantly changes as aircraft are retired,engines and modules are acquired or putthrough varying scopes of shop visit (SV)and maintenance. The supply of enginesand modules at times can be so high as tomake any form of maintenance SVuneconomic. The eventual result of this isthat the supply of time-continuedmodules and engines declines and soincreases their value, with the eventualresult that SV maintenance becomeseconomic again.

Maintenance management Maintenance management for engines

in their early and mature phases of lifewill be based on maintaining all majorelements of the engine to achieve thelongest possible intervals betweenmaintenance removals. It will also keepthe engine in a high maintenance andserviceable status.

The first element of maintenancemanagement to consider is the engine’sairfoils and its operating performance, inparticular its exhaust gas temperature(EGT) margin. EGT margin will be at itsmaximum at delivery, and will steadilydecline with continued use and operation.This is mainly due to airfoil deterioration.Performance will, therefore, decline withEGT margin, and SV maintenance will berequired to restore airfoil status and EGT

margin to a level that achieves a longsubsequent removal interval.

Engine management may aim to havean engine removal and SV for EGTmargin restoration, and airfoilmaintenance status restoration in amodule or several modules to coincidewith the need to replace life limited parts(LLPs) of disks and shafts in the module.If achieved, all elements of the module’smaintenance status is restored to itshighest level at the same time. Managingengines in this way achieves the lowestmaintenance costs per engine flight hour(EFH) or per engine flight cycle (EFC).

The issue is complicated by thediffering rates of performancedeterioration in engine modules, and alsothe different life limits of LLPs in EFCs indifferent modules. The high pressureturbine (HPT) and combustion chamberhave the shortest removal intervals due todeterioration, and are often followed bythe high pressure compressor (HPC). TheLLPs in these two modules often haveequal or similar lives.

The low pressure turbine (LPT), lowpressure compressor (LPC) and fanmodules will have longer maintenanceintervals. They usually requiredisassembly for maintenance at everysecond SV, and in some cases every thirdSV. Their LLPs also have longer lives thanparts in the high pressure (HP) and hightemperature modules.

Maintenance and replacement of allairfoils and accessory components, andthe maximum utilisation of all LLPs, aswell as engine cases, is necessary to keepan engine operational and to maintain thehighest market value.

These priorities change, however,when large numbers of used engines comeavailable on the market. Management ofengines in the older phases of operationallife can take advantage of several issuesthat help operators minimise maintenanceactivity and costs. The first of these isthat many engines will no longer be

Fleets of 1980s generation narrowbody & widebody engines have beendeclining and imploding for the past 10-12 years. The remaining MROmarket for each engine type, and some of the remaining engine shops foreach type are examined.

MRO options older &mature engine types

subject to fixed maintenance cost perhour or cycle contracts. Operators are,therefore, free to determine their ownworkscopes, and can also choose fromtime-and-material, never-to-exceed(NTE), or fixed-price maintenancecontracts that are offered by the enginemaintenance shops.

Another advantage to themaintenance management of olderengines is that LLPs in the fan, LPC andLPT modules have lives of up to25,000EFC, and in a few cases30,000EFC. The main benefit of this isthat in engines operated on long-haul andlong EFH:EFC ratios, the replacement ofLLPs in these modules may have onlybeen performed once, and at the latterpart of the engine’s life. Since aircraft

operate long- and medium-haul flights,engines operate at 3.0-8.0EFH per EFC,so engines and LLPs will only accumulate350-1,000EFC per year. This means it ispossible to operate older engines withoutever having to replace all or at least someof the LLPs for a second time. Thisgenerates substantial cost savings.

When the longer life LLPs of LPTmodules is combined with relatively longmaintenance intervals, it is also possibleto swap the modules of different enginesaccording to maintenance status. It is,therefore, feasible to avoid themaintenance of several modules or evenan entire engine by swapping the modulesof two or more engines according tomaintenance status to produce one enginethat can continue to operate with the

minimum of maintenance inputs. Another element to consider is the use

of used serviceable material (USM). Thisapplies to airfoils, smaller components,LLPs and external accessory components.In the case of USM, airfoils can berepaired to the level that achieves asubsequent removal and maintenanceinterval that is economic for the operator.Extensive and hi-tech repairs or thereplacement of parts will incur highercosts while increasing EGT margin andengine performance, which may notnecessarily be required by the operator.

The cost of performing maintenanceon each module, the acquisition cost ofthe engines, the likely interval before thenext maintenance workscope is requiredand the probable cost of the workscopefor each module, and the operator’s fleetplans, all have to be considered. This willbe on a case-by-case basis, since thesefactors, particularly engine and modulevalues and the cost of SVs, are constantlychanging. Many engine shops thatperform maintenance for mature andolder types have developed techniquesand SV workscopes that provideadequate EGT margin and performance,and, therefore, maintenance intervals thatmeet the operator’s requirements.

PMA parts & DER repairs One issue that affects the economics

of continued operation of these engines isthe use of manufacturer approved (PMA)parts and engineering representativerepairs (DERs).

PMA parts are designed, developedand manufactured by companies otherthan the OEM. In the case of theCFM56-3, some airfoil components havebeen made by HEICO and Chromalloy.Moreover, Pratt & Whitney EngineServices reverse-engineered the CFM56-3and developed a range of PMA parts forairfoils in the engine. PMA parts aregenerally viewed as having the sameoperational and performance qualities asOEM parts, but have the advantage ofbeing cheaper and reducing SV costs. It ispossible to reduce the cost of an SV inputby as much as $100,000 through the useof PMAs. The saving will be less in thecase of older engine types that areundergoing smaller and minimalworkscopes that avoid a high level ofparts replacement.

The use of PMA parts has becomecontroversial, and is avoided by someairlines because the OEMs are not able toprovide warranties and guarantees for theremaining components and parts of theengine when used in association withPMA parts. Airlines are free to use PMAparts, however, and they will lower SVcosts if used.

DER repairs are non-OEM, hi-techand specialist repairs developed by



FLEETS OF OLDER AIRCRAFT TYPES

Aircraft Engine In service In service In service Aircraft Active Agetype type passenger freighter other in service engines range

NARROWBODIES

MD-80 JT8D-200 289 10 13 312 624 19-37

737-500 CFM56-3B 134 73 19 226 452 19-33

737-500 CFM56-3C 331 200 21 552 1,104 19-32

757-200/-300 PW2000 161 102 3 266 532 14-34

RB211-535 203 205 11 419 838 14-35

WIDEBODIES

A300-600/A310 PW4000-94 6 111 117 234 12-32

MD-11 PW4000-94 43 43 129 19-28

747-400 PW4000-94 30 58 5 93 372 9-29

A300-600/A310 CF6-80C2 - PMC 36 20 17 73 146 22-32

A300-600/A310 CF6-80C2 - FADEC 1 50 0 51 102 11-25

MD-11 CF6-8-C2 - FADEC 78 78 234 17-28

747-400 CF6-80C2 - FADEC 66 126 4 196 784 9-29

767-300/-400 CF6-80C2 - FADEC 247 194 8 449 898 0-30

A340-200/-300 CFM56-5C 98 6 104 10-25

A300B2/B4 CF6-50 4 10 14 34-38

DC-10-30 CF6-50 16 5 21 30-45

747 CLASSIC CF6-50 1 5 6 27-31

A300B2/B4 JT9D 0

A300-600/A310 JT9D/CF6-80A 0

747 CLASSIC JT9D 3 10 11 24 30-49

747 CLASSIC RB211 1 3 4

747-400 RB211-524G/H 39 17 0 56

Total 1,699 1,329 127 3,155 7,418

52 IMAINTENANCE & ENGINEERING 53 IMAINTENANCE & ENGINEERING

ISSUE NO. 118 • JUNE/JULY 2018 AIRCRAFT COMMERCE

independent and airline-affiliated engineshops. Similar to the qualities of PMAparts, DER repairs are regarded as havingsimilar or equal qualities to OEM repairs.As DER repairs are cheaper, they can alsocontribute to reducing the cost of SVs. Amix of DER and OEM repairs is offeredon airfoils by specialist providers such asChromalloy.

MTU Maintenance is a provider ofDER repairs. While it also offers OEMrepairs, MTU Maintenance has developedits in-house DER repairs which it marketsas MTU Plus. MTU Maintenance statesthat the use of DER repairs greatlyincreases the cost-effectiveness of an SVworkscope when compared to replacingparts with new parts or using OEMrepairs. DER repairs contribute tolowering the scrap rate of parts,improving durability of hardware, andreducing the engine’s specific fuelconsumption (sfc). Overall, MTUMaintenance states that DER repairs helpcombat high parts and material costs andconsiderably increase engine removalintervals. The repairs can givecomponents up to three more lives. Mostcustomers will consider DER repairs toreduce maintenance costs for olderengines in their last years of operation.

Some shops report that customers nolonger want PMA parts, but want to useDER repairs. A main factor in this choice

is that airlines know they are still able toacquire time-continued and green-timeengines and modules with sufficientremaining time on-wing to avoid full SVworkscopes. Also, the use of USMmaterial and use of surgical strikes andrelatively cheap repairs is often the mosteconomic option for most airlines.

“Some of our customers do ask to usePMA parts in SVs, when one is required,and we allow this if requested,” saysGordon Humphreys, director of sales andbusiness development at LMES, a smallprovider of CFM56-3 maintenance. “Wedo not actually market the use of PMAparts, but PMA airfoils and exteriorcomponents are available and can beused.

“We do a lot of part repairs in-house,and these include some for vanes andstators, honeycomb seals, combustionchambers, fan blades, and engine cases,”continues Humphreys. “We do not dorepairs for rotating airfoils. The repairswe offer are OEM-approved repairs, andwe sub-contract the repair of rotatingairfoils to providers, such as Chromalloy,for DER repairs to help reduce the cost ofthe SV.”

GEM has a similar policy to LMES,and does what its customers want withrespect to PMA parts and DER repairs.“We will recommend the use of bothPMA parts and DER repairs, but only if

it makes economic sense,” saysHumphreys. “This will usually be thecase when an airline needs an engine for alonger removal interval, and so needs acomprehensive workscope. We are veryopen to cheaper alternatives for enginemaintenance. The savings from the use ofPMAs and DERs can be substantial.”

JT8D-200 The JT8D-200 exclusively powers the

MD-80 family. More than 2,500 JT8D-200s and 1,191 MD-80s were built from1980 to 1999, and 312 MD-80s areactive (see table, page xx). These are 19-37 years old. Of these, 289 are inpassenger configuration, while 10 areoperating as converted freighters. Thereare, therefore, more than 620 installedengines on the active fleet.

There are few engine shops left withJT8D capability, the type having twomain series of the ‘Baby’ and -200. TheBaby JT8Ds power a small number ofDC-9s, 737-300s and 727s left in service.

Two main shops with JT8D capabilityare Aerothrust and Global EngineMaintenance (GEM), both in Miami,Florida. GEM is located west of MiamiInternational Airport in a new 100,000square feet facility. The company startedengine maintenance in 2012. “We havethe capability to do about 100 SVs per



year, and are ramping this up to 150,”says Faryt Kalhil, president and chiefexecutive officer at Global EngineMaintenance. “We are building a test cellthat will have a 50,000-75,000lbs thrustcapability.

“We have extensive capability forengines that includes module swap, smallSVs that we call ‘hospital visits’, on-wingor field support, engine disassembly andre-assembly, piece-part inspections, andpiece-part and module repairs. This lastelement includes third-party work,”continues Kalhil. “We perform all typesof parts and airfoil repairs that includewelding, and grinding and blendingrepairs. The only ones we do not performare environmental and high-tech repairs,such as laser drilling or those that requireplasma spray, or application of coatings.”

GEM’s annual activity for the JT8D-200 is only a small number of SVs. “Wedo see quite a lot of activity each year, butdo not expect to have a long-term futurein this engine. We only performmaintenance on the JT8D-200 for knownor established customers,” says Kalhil.“Each year we perform full SVs andperformance restorations, and total SVsper year on the type reach about 15. Ourmain customers are Latin Americanairlines and those with VIP aircraft. Wewill keep capability for the JT8D whilethere is demand. We do, however, haveplans to expand lines for other enginetypes, so we have to make room forthose. We no longer actively market theJT8D.”

As well as SV maintenance, GEMacquires modules and engines for sale andleasing. “We use these to sell to airlines orexchange full engines and modules. Wealso do a lot of engine trades,” says

Kalhil. “We also acquire used materials,and are always active in acquiring time-continued parts and engines. We have alot of time-continued and overhauledparts in engines. We provide airlines witha host of options so that they can keepthe maintenance cost for these engines toa minimum. We no longer lease JT8Dengines, however.”

CFM56-3 Of all the old engine types listed, the

CFM56-3 is the most numerous (seetable, page xx). Out of 1,940 737Classics built, about 780 aircraft are stillin active service, and which are 19-33years old. The 737-300 and -400 haveproven to be popular freighters, withpassenger-to-freighter conversionprogrammes offered by AEI, IAI BedekAviation, and Pemco. There are 273aircraft in active service as freighters, andmore aircraft will continue to beconverted. There are also more than 460aircraft in service in passenger-configuration, despite the large-scaleretirement of these types by first-tieroperators and major airlines.

The fleet of active aircraft means thatthere will be a mix of almost 1,560installed CFM56-3B and -3C engines onoperating aircraft, and up to 250 moreengines will be required as effectivespares. These could be sourced as green-time engines from the large number ofretired aircraft. To date, about 900 737-300s/-400s/-500s have been retired orwritten off, so these aircraft have releasedabout 1,800 -3B and -3C engines. Thesealso provide a supply of USM for use byengine shops.

With almost 800 active 737 Classics,

there are still several shops that offerCFM56-3 capability. Estimates are thatthe global CFM56-3 market equals 130SVs per year.

The remaining shops with CFM56-3capability include Aero Norway inStavanger, Norway; MTU Maintenance,with shops in Canada and Zuhai, China;GEM in Miami; Lockheed Martin EngineServices in Montreal, Canada; and IsraelAircraft Industries (IAI) in Tel Aviv,Israel.

Aero Norway has become one ofEurope’s largest providers of CFM56-3maintenance. “There has been aresurgence in CFM56-3 activity becauseof the low market values of 737 Classicsand the demand for freighters,” saysGlenford Marston, chief executive officerat Aero Norway. “There is also theunexpected continued operation ofpassenger-configured aircraft. The highdemand for 737NGs, with values at $12-14 million, has kept values of 737Classics at $2-3 million. The aircraft haveremained profitable to operate for longerthan many expected.”

Although there are still large numbersoperating, the aircraft left are 19-33 yearsold. “Most 737 Classic operators try toavoid performing SVs, and mostmaintenance inputs are full corerestorations. We do not see completeoverhauls, and airlines try to avoidperforming maintenance on the LPmodules to save costs. The LLPs in the LPmodules have lives of 25,000-30,000EFC,while those in the HP modules have livesof 15,000-20,000EFC. This helps airlinesavoid workscopes on the LP modules.There are a large number of engines fromretired aircraft with time-continuedmodules to help with this.

“We also have CFM56-5B and -7Bengines, which now account for about35% of our SV activity. The CFM56-3accounts for about 65% of ourmaintenance activity. This is equal toabout 38 SVs per year,” adds Marston.“We could actually get more -3 work, butwe are limited by capacity.

“Most maintenance visits are moduleswaps and small visits that we callsurgical strikes,” continues Marston.“This is a workscope to provide enoughEGT margin to match the remaining EFClives of the LLPs in the HP modules.”

GEM actively markets its CFM56-3capability, and its main customers are

The remaining fleet of in-service MD-80s stillgenerate demand for engine shop visits for theJT8D-200. Active engine shops include GlobalEngine Maintenance and Aerothrust in Miami.

passenger operators, as well as enginelessors and traders, and freight carriers.“The -3 is a good workhorse, and we aredoing 50-60 engines per year. We alsoown 20 or more engines, and offer themfor sale or do exchanges with ourcustomers,” says Kalhil. “These enginesmean we can give an operator aserviceable engine at any time, which ispart of the method of managing olderengines to keep maintenance costs as lowas possible. Moreover, there is a strongsupply of good quality engines availablebecause of the large number of aircraftthat have been retired.” This includesabout 450 -3C-powered aircraft.

As with Aero Norway, GEM’scustomers do not want full managementservice for their -3s. “The customers sendus the engine condition and data, and werecommend a workscope and the likelycost,” says Kalhil. “We give ourcustomers a warranty of on-wing time of18-24 months. Sometimes we can advisethe customer that the engine can have asmaller workscope than thought.”

MTU Maintenance is one of thelargest remaining providers of CFM56-3maintenance, performing about 20CFM56-3 SVs per year, plus another fivesmaller maintenance events for theengine. Smaller events include engineteardown, end-of-lease repetitiveinspections, single module repairs, andlight repairs that may also be referred to

as surgical strikes or hospital visits. LMES is an engine maintenance

facility that was previously operated byAir Canada and then Aveos. “We onlyperform about 10 SVs per year for the -3,and no longer actively market ourcapability for the engine,” saysHumphreys. “Our customers are mainlysmall niche operators from Canada andthe US. We find, as may be expected, thatmany of our customers avoid full-level SVworkscopes because they can keepoperational by using green-time engines.We are looking to the -5B and -7B in thefuture for full maintenance activity, butwe can still support the -3.

“We expect the market to last foranother three to five years. We provide alllevels of engine SV workscope, includingsimple module swap, module disassemblyand re-assembly, full detailed module andpiece-part inspections, componentrepairs, and airfoil parts and repairs,”continues Humphreys. “We mainly offertwo types of support contracts. These areusually fixed-price contracts or moduleswaps if the customer requires.”

IAI in Tel Aviv is one of the fewproviders of -3 maintenance and supportin the Mediterranean, Middle East andAfrica. “We perform about 100 SVs peryear for all engine types, and the CFM56-3 accounted for about 15 of these in2017,” says Jacob Rozman, vicepresident and general manager of IAI

Engine Division. “The interesting issueabout the -3 market is that there areseveral facilities in China that haveremoved or reduced their -3 capabilities.This is generating extra -3 business for us.We also offer module swaps as a way ofreducing a customer’s costs. We offertime-and-material, NTE and fixed-pricecontacts. We can also offer power-by-the-hour (PBH) contracts for airlines that areinterested.”

IAI also owns a small portfolio ofengines available for lease. In addition tothe CFM56-3, the portfolio includes theV2500-A5/-A7, and a single PW4000-94.

MTU Maintenance’s range ofcapabilities is among the largest. Thisincludes the more basic items of incominginspection, disassembly of engines andmodules into piece parts, repair andupgrade of components and accessories,gapping and grinding processes forcompressor and turbine airfoils, andmodule and engine re-assembly.

Most shops have some level ofcomponent repair capability, but high-tech repairs are left to specialists. “We dohave capability for variable bleed valve(VBV) systems and plasma spray, but noton airfoils,” says Marston. “We only domanual repairs on airfoils, which are allin the original equipment manufacturer(OEM) manuals. These are described inthe engine shop manual (ESM). We donot do any source-approved airfoil






repairs. It is actually cheaper to sub-contract some of the specialist and hi-techparts repairs because of the volumeexperienced.”

Like many other providers, IAI is notauthorised to perform hi-tech andspecialist part repairs, such as for theHPT blades. “We do repairs on mostairfoils and the combustion chambers,however, and also the nozzle guide vanes(NGVs),” says Rozman.

PW2000 The 757 fleet has about 680 active

aircraft out of the 966 aircraft that werebuilt. The fleet is sub-divided between thePW2000- and RB211-535-poweredaircraft. The RB211- equipped fleet wasthe larger of the two, with 541 aircraftbuilt, of which about 419 still in activeservice. The PW2000-equipped fleettotalled 425 aircraft, and 266 are stillactive (see table, page xx). These are 14-34 years old, the last aircraft being builtin 2004. There are about 160 aircraft stillin operation as passenger-configuredaircraft. Most of these are in service withDelta Air Lines, and a small number arein operation with United Airlines.

There are 102 PW2000-powered 757freighters in operation. Many of these arefactory-built freighters operated by UPSand FedEx, but there are also someconverted aircraft. The 757 is also in aclass of its own, and it is expected tocontinue in operation for another 20years. Moreover, there are large numbersof the PW2000’s military variant, theF117, in operation powering the C-17fleet.

There are a few choices for enginemaintenance capability. These include PWColumbus, CTS Engines in Miami and

MTU Maintenance Hannover and Dallas,and Dela TechOps in Atlanta.

With about 266 aircraft in service,there will be at least 532 activecommercial engines in operation.Estimates are that this generates 100 SVsper year. “This increases to about 200SVs per year when the military variantF117 is included,” says Vesa Paukkeri,president and chief operating officer atCTS Engines. “We will start to offerPW2000 capability from late 2018. Wehave already begun to tear down engines,which will provide us with modules andUSM. So far we do not have anycustomers secured, but there are about300 C-17s, each with four engines. Weexpect freight operators and lessors to useus. We see the PW2000 as a nichemarket, and expect to keep operationalfor the next 20 years. We expect a waveof 757 retirements, but there will still bebig operators.”

MTU Maintenance performs about20 PW2000 SVs per year, and so hasabout 10% of the total estimated market,but about 20% of the civil PW2000market. It also performs another fivesmaller SV events for the PW2000 eachyear. The smaller events are small or lightrepairs, end-of-lease returns andteardown.

As with other engine types, MTUMaintenance has developed extensivemaintenance capability for the engine. Itsmain aim with older engines, like thePW2000, is to repair as much material aspossible, rather than replace with newparts. It aims to repair as many parts aspossible in-house within the MTUnetwork. MTU Maintenance can,therefore, maintain better cost control. Aswith other engine types, MTUMaintenance actively promotes and uses

its in-house DER repairs as acontribution to keeping enginemaintenance costs to a minimum.

CFM56-5C The CFM56-5C is the sole engine on

the A340-200/-300 fleet. There are 104active aircraft out of 236 built. The activefleet has 416 installed engines. Theretirement of more than 130 aircraft andof complete fleets by several airlinesmeans there will be more than 550 retiredand time-continued engines on themarket.

The remaining 104 aircraft areoperated by a mix of original operatorsand airlines that have acquired usedaircraft. Original operators includeAerolineas Argentinas, Air France, AirMauritius, Lufthansa, South AfricanAirways, TAP Air Portugal, and TurkishAirlines. Many of these fleets are due forretirement over the next few years, andwill be replaced by several types thatinclude the 787 and A350. This willrelease further CFM56-5Cs onto themarket. Airlines operating used fleetsinclude Air Belgium, Edelweiss, SWISS,Hi Fly, Joon, Kam Air and Plus Ultra.

There were several engine shops inEurope that had -5C capability, but manyhave now left the market. Remainingengine shops Iberia Maintenance, TAPMaintenance & Engineering, TurkishTechnic and Lufthansa Technik.Lufthansa Technik has retained itscapability for use on the Lufthansa fleet,and it also supports SWISS andAerolineas Argentinas. Lufthansa will bephasing its fleet out over the next fewyears, although the exact timing willdepend on fuel prices. “The rate ofretirement by Lufthansa, therefore, affectsits engine maintenance strategy,” saysMarc Wilken, product sales seniordirector at Lufthansa Technik. “Over thelast few years we have completed 20-30SVs per year for the CFM56-5C. The -5Cis maintained on the same product line asthe -5A at our Hamburg engine shop.

“We offer customised enginemaintenance, and have a product calledSmartLife,” continues Wilken. “We offerthis for older engines in the latter part oftheir life, and we provide bespokesolutions for airlines operating olderengines. We examine the LLP status ofeach engine, and what maintenance is

The CFM56-3 MRO market is equal to about 130shop visits per year. The large number of greentime engines available on the market meansthat most operators seek minimal workscopes,such as surgical strikes, to avoid the cost of fullworkscopes. In the case of most shop visits, LPmodules do require minimal work.



required to achieve a particular removalinterval, taking the operator’s fleet plansinto consideration. We also offer mobileengine services, where we can performsome engine repair work on-site as analternative to performing a full SV at ourHamburg shop. We have several repairstations, located in: China; Tulsa,Oklahoma; Frankfurt, Germany; andMontreal. Engine repair work on-site issimilar to hospital visits offered byGeneral Electric.”

Lufthansa Technik has extensiveengine shop capability that includes alllevels, from incoming inspection anddisassembly into modules, to parts andcomponent repairs. Lufthansa Technikhas its own hi-tech and specialist engineparts repairs called EPAR. It also has aspecialist repair facility in Shannon, and ajoint venture with MTU Maintenance inrelation to a component repair facility inChina. “We find that mid-life engines,such as the CFM56-5C, have the highestlevel of mid-life parts repairs,” saysWilken. “The number of repairsperformed depends mainly on theavailability of USM from retired engines.Mature engines tend to repair fewer partsrepairs, and module swaps become morecommon. We may have to eventuallydrop our CFM56-5C capability ifdemand for these specialist repairs fallsbelow an economic level.”

CF6-50/-80C2 The General Electric CF6 has been

one of the most successful widebodyengines. Two of the four distinct variantswere the CF6-6, powering the DC-10-10,and the CF6-80A, powering the earlyvariants of the 767-200 and the A310.Only a small number of these engines

remains in service. The other two variants still in

operation in larger numbers are the CF6-50, powering the A300B2/B4, DC-10-30and 747 Classics, and the CF6-80C2,powering 1980s generation widebodiesthat are the A300-600, A310-300, MD-11, 747-400, and 767 family.

There are still 41 A300B2/B4, DC-10-30 and 747 Classics in operation that arepowered by CF6-50s (see table, page xx).This amounts to 115 active installedengines.

The 14 A300B2/B4s are mainlyfreighters, and are operated byAeroUnion, Global Charter and DHL. Afew passenger-configured aircraft areoperated by Iran Air. The 21 DC-10-30sare operated by FedEx, plus a few aircraftconfigured as firefighting aircraft. Thereare five freighter-configured 747-200sthat are mainly Iranian and Belarussian.

There are 396 A300-600s, A310-300s, MD-11s and 747-400s in service,which equates to about 1,262 activeinstalled CF6-80C2 engines (see table,page xx). To date, 138 A300-600/A310-300s, 41 MD-11s and 134 747-400sequipped with CF6-80C2 engines havebeen retired. This is equal to more than900 engines coming onto the usedmarket.

There are, however, another 531 CF6-80C2-powered 767-300ERs and -400ERsstill in service, while 69 CF6-80C2-equipped 767s have been retired.Therefore, more than 1,000 CF6-80C2engines have released onto the usedmarket due to retirements.

The remaining in-service CF6-80C2fleet comprises about 2,300 engines, andso is the largest of older widebody enginetypes on the market, second to thePW4000-94 which has a larger installed

base. There are also additional CF6-80C2s in service with military aircraft,while the CF6-80C2 is also still inproduction with remaining 767PFs to bebuilt over the next six years.

The number of retired and in-serviceengines has to be treated with caution.The CF6-80C2 fleet is sub-dividedbetween two fleets of power managementcontrol (PMC) and full authority digitalengine control (FADEC) units. There aredifferent thrust-rated variants within eachsub-family, but it is not possible to swapvariants between each family.

The A300-600 and A310 wereequipped with a mix of PMC and FADECengines, while the MD-11 and 747-400were equipped exclusively with FADECengines. The majority of CF6-80C2-powered 767-300s/-400s were equippedwith FADEC engines, although 124 olderaircraft were equipped with PMCengines.

In total, there were 986 aircraft of allfour main types built with FADECengines, of which 212 have been retired,written off or parked. Most of the retiredaircraft are 747s, and so this released atleast 660 FADEC-equipped engines ontothe aftermarket. There are 774 aircraftwith more than 2,000 FADEC-equippedengines installed.

While the 767-300ER fleet is largelystable and remains popular, largenumbers of A300-600s, A310-300s and747-400s have been retired, withadditional aircraft to be retired over thenext few years, releasing additionalengines onto the market.

The A300-600s/A310-300s in serviceare operated by a mix of small fleets thatinclude Air Transat, Ariana AfghanAirlines, Iran Air, Mahan Air, MNG, andTurkish Airlines. The remaining MD-11sare freighters operated by FedEx, WesternGlobal, Lufthansa Cargo, Sky Lease andUPS. The smaller fleets among these arelikely to retire over the next few years ifhigh fuel prices are sustained.

Large numbers of mainline 747-400fleets have been retired. The 66 passengeraircraft that remain in operation includeAsiana, KLM, Qantas, Lufthansa, ThaiAirways International and VirginAtlantic. Many of these are due forretirement, and so will release moreengines on to the market. There are also126 freighters and Combi aircraft inoperation, but most of these more arelikely to remain in service.

The PW2000 is a select market, although thefleet of active 757s plus about 300 C-17sgenerates a market estimated at about 200shop visits per year.

The CF6-50 maintenance market isestimated at 25 events and SVs per year,with another 40 maintenance events forthe USAF KC-10 tanker fleet.

The extensive use and popularity ofthe CF6-80C2 resulted in a large numberof shops with capability. These are nowdeclining. Estimates are that the annualmaintenance market is equal to 500 SVsper year, excluding military engines usedon types such as the 767 refuelling tanker.

There are now few providers of CF6-50 engine maintenance. Shops that stillhave the capability are CTS Engines inMiami, and LMES at its facility inMontreal. CTS Engines’ main customerfor the CF6-50 is the US Air Force(USAF), for the KC-10 fleet.

The other main supplier for the USAFis LMES. “We perform maintenance forthe CF6-50 on military contracts formore than 40 KC-10s that are operatedby the USAF,” says Humphreys. “Unlikecivil engines, these USAF engines havefull maintenance management, since theywill probably continue to be operated foranother 10-12 years.

“We do not do a lot of marketing tocommercial customers for the CF6-50,because there are very few operatorsleft,” continues Humphreys. “We do,however, have the capability for theengine. We can perform about 75% ofparts repairs in-house, and subcontractthe rest. The repairs we perform in-houseinclude those for vanes and stators,honeycomb seals, combustors and fanblades. Sub-contracted repairs tend to bethe specialist repairs for rotating airfoils,and we can use DER repairs fromproviders such as Chromalloy for these.”

Providers of CF6-80C2 capabilityinclude Air France Industries KLMEngineering & Maintenance, LufthansaTechnik, MTU Maintenance and CTSEngines.

“The advantage of our having thecapability for the CF6-80C2 is that themarket has been going up over the pastfew years, despite the large number ofretirements,” says Paukkeri at CTSEngines. “This is explained by many largeoperators retiring fleets and changing toother engine types in their shops.Independents like GE Caledonian havealso left the market, and some shops likeLufthansa Technik have less CF6-80C2activity. The past few years has also seenmany airlines using time-continuedengines and modules to minimisemaintenance costs, but these have now

been used. Airlines are now having toperform full workscopes, at least on somemodules because of the supply being usedup. The economy is also picking up, andthis is driving demand for cargo. Ashortage of freighter capacity hasmaterialised, and types like the 747 are indemand again.”

Lufthansa Technik has maintainedsubstantial CF6-80C2 activity for severaltypes operated by Lufthansa, but its fleethas declined. “We perform 25-30 SVs peryear,” says Wilken. “Lufthansa stilloperates about 13 747-400s and it alsooperates MD-11Fs. Despite this, werarely see big tenders from airlines formaintenance contracts for the engine typebecause airlines have been takingadvantage of the supply of used and time-continued engines and modules on themarket, as well as competition amongsuppliers.”

MTU Maintenance performs about12 SVs and events per year for the CF6-80C2. MTU Maintenance experiencesmainly lighter workscopes for the CF6-80C2. Like CTS Engines, MTUmaintenance has experienced a revival inthe CF6-80C2 maintenance market. Itclaims this is due to the rise in freightercapacity and a lower rate of retirementand the fewer older CF6-80C2-poweredaircraft being parked. This latter factor isdue to delays in new widebodyprogrammes, and older aircraft havebecome attractive again. All of theseissues have diminished the availability ofsurplus material and engines.

CTS Engines’ customers include theUSAF for the E-4B fleet, Asiana, DHLand Lufthansa. “Despite Lufthansa stilloperating the 747-400 and LufthansaCargo operating the MD-11, not a lot ofits engines go through Lufthansa

Technik,” says Paukkeri. “We have alsobeen buying engines, although we are notgetting into trading. We are filling everyslot with overhauls and are getting thebest value from full SVs.”

Wilken at Lufthansa Technik saysthat most CF6-80C2 operators areinterested in keeping the engineoperational at minimal cost. “Thecustomers leave management ofdetermining the best workscope, whatmodules to swap and which LLPs toreplace to Lufthansa Technik,” saysWilken. “This includes the use of USM,which is up to 90% in the case of theCF6-80C2.

“In addition to this, we do permit theuse of PMAs when parts need to bereplaced in the CF6 if the customerrequests it,” continues Wilken.“Lufthansa Technik had developed PMAparts, but their use has mainly beeninfluenced by external parties, especiallylessors. We use PMA parts in the CF6-80C2s operated by Lufthansa andLufthansa Cargo. We also use the DERrepairs that were developed by our EPARdivision. PMAs and DERs may notalways be used that much if there is asupply of suitable USM.”

Despite the remaining fleet of CF6-80C2s exceeding 2,000 engines, Wilkensays he expects Lufthansa Technik toremain in the maintenance market foranother three to five years, once the lastaircraft operated by Lufthansa andLufthansa Cargo retire. “The main factorwill be the extent of our activity for thenew engine types.”

MTU Maintenance says it will keepcapability for the CF6-80C2 for as longas there is sufficient customer demand,and adds that it has seen renewed interestin the engine for the past two years.



Lufthansa Technik has maintained its CFM56-5Ccapability. The fleet of A340-200s/-300s is nowabout 100 active aircraft, and generates demandfor 20-30 engine shop visits per year for theprovider.


Because many of its customers are freightoperators, it does not expect to exit themarket any time soon.

Reducing and then resurgentmaintenance activity is typical of adeclining fleet of active engines. Activitywill naturally decline as the supply oftime-continued engines increases, andthen will rise again as that supply is usedup. The continual retirement of CF6-80C2-powered aircraft will result inreductions in engine maintenance activity,followed by the inevitable resurgence ofmaintenance activity.

PW4000-94 & JT9D The PW4000-94 is the second most

numerous of older generation widebodyengines. There are 117 active A300-600s/A310-300s, 43 MD-11s and 93747-400s that are equipped with severalthrust-rated variants of the PW4000-94(see table, page xx). These aircraft willhave about 735 installed engines. Thiscompares to 276 retired aircraft of thesame three types, and these will havereleased 874 installed engines plus spares.

As with the CF6-80C2, the PW4000-94-powered aircraft still in operation inlarge numbers are 767-300ERs. Theaircraft in operation are virtually allfreight operators in the case of the A300-600/A310-300, while all but two MD-11Fs are operated by courier servicesFedEx and UPS. The PW4000-powered747-400s in operation are split between58 freighters and 30 passenger aircraft.Freighter operators include a variety ofsmall cargo carriers and larger airlines,such as Cathay Pacific, Cargo Air Lines,Kalitta Air and Singapore Airlines.

Passenger-configured aircraft are stilloperated by Air China, Air India, Corsair,El Al, Korean Air, Saudia and Wamos Air.Many of these fleets are due to be phasedout over the next several years.

The relatively small fleet of 156passenger-configured 767-300ERs isoperated by a mix of large and first-tierairlines, and smaller carriers that includeused fleets. First-tier fleets include AirCanada Rouge (12 aircraft), Delta AirLines (32), United Airlines (35),Hawaiian Airlines, Condor and EthiopianAirlines. Smaller fleets include AirAstana, Azur Air, Ukraine InternationalAirlines and Uzbekistan Airways.

About 62 767-300s have been retired,meaning about 1,000 engines have beenreleased from retired and written-offaircraft.

The number of engines from retiredaircraft is, therefore, almost equal tothose in operation with active aircraft.The number of retired engines is alsolikely to increase in relatively largenumbers over the next few years asairlines such as Delta and United phaseout their 767-300ERs replacing themwith 787s and A350s. The maintenancestatus of these engines coming onto themarket may not be too high, since Delta’spolicy is to use up most availablemaintenance time on its engines, andswap engines and modules as it graduallyphases out aircraft.

There are several shops that havemaintained some level of PW4000-84capability. These include LufthansaTechnik, Hamburg; IAI, Tel Aviv; PWEagle Services, Singapore; Air IndiaEngineering Services, New Delhi; andDelta Tech Ops, Atlanta. PAS

Technologies and Standard Aero areproviders of a selection of parts andcomponent repairs.

Estimates are that the globalmaintenance market for the PW4000-94engines is equal to 230 SVs plus smallerevents, and up to 400 SVs in some years.The PW4000-94 market will experiencedeclines and resurgences in themaintenance market as retired time-continued engines are first used byairlines to avoid expensive SVs, and thenhave to be sent for extensive shop eventsas the supply of green-time modules andengines dries up. The supply of green-time engines will not necessarily increasesignificantly.

“We have seen a reduction inPW4000-94 activity, as well as the JT9Dwhich we also have capability for. Weonly perform about 100 SVs per year forall the types we have capability for,” saysRozman at IAI. “We think it will be a fewmore years before the JT9D is totallygone from the market. There is still alarge number of 767s operating. Thereare alternative shops, however, and it hasbecome difficult to obtain USM.Moreover, PW no longer manufactures allof the parts for the engine.

“Besides the main levels of enginemaintenance capability, we offer repairsthat are authorised by the OEM,”continues Rozman. “We are now findingthat no customers are asking for PMAparts, but they did in the past. They alsodon’t want DER repairs. This is mainlybecause they can still acquire time-continued engines and modules.”

In the case of the JT9D, there are nowonly 24 active aircraft with the enginetype in operation. These are all 747Classics. They include 11 aircraft that arein government, research and VIP roles;three passenger aircraft operated by MaxAir of Nigeria; and 10 freighters, most ofwhich are operated in Iran.

“We will continue with JT9Dcapability until the market is dead,” saysRozman. “Most aircraft are freightersand VIP, and we are now assigned as aservice provider for the JT9D by PW.There seems to be little or no green-timeJT9D material available.



The CF6-80C2 is an active fleet of about 2,000installed engines. The full utilisation of largenumbers of green time engines from previouslyretired aircraft has led to a resurgence indemand for shop visit maintenance of the type.

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