It is a measure of the engine manufacturers’ troubled times that their recent appearance on a panel at a major industry conference was rocked by calls from delegates to apologise for failing to deliver on their promises.
The event was the European round of ISTAT in Berlin, which brought together some of the airframe and engine OEMs’ most important clients – the leasing and financing community. And although Emirates Airline president Tim Clark was absent, his recent criticism of engine manufacturers – and to a lesser extent airframers – echoed around the auditorium on several occasions.
“I’m a little bit irritated that over the years we as an airline, and the industry, have been subjected to the requirements of the propulsion manufacturers, and to an extent the airframe manufacturers, where we are expected to deal with quality-control issues, design issues etc, and operate these aircraft and engines and take whatever consequences there are when they don’t work,” he said in September.
Airlines are unwilling to get out of bed for anything less than “99.5%” dispatch reliability, says Clark: “We are not in a business to deal with aircraft that don’t function properly.”
The main recipients of Clark’s criticism were the GE Aviation GE9X and the Rolls-Royce Trent 1000. The former should already be powering the Boeing 777-9 on its flight-test programme but has instead caused a major delay amid a redesign of its high-pressure compressor. The latter’s ongoing turbine blade issues have severely disrupted operations of R-R’s 787 customers.
Speaking at ISTAT, senior marketing director Chris Nye said GE “hopes to get the [revised] engines tested and certified this year”. This will be crucial to enable the 777-9 to fly as early as possible in 2020.
The stark reality for the airframe manufacturers is that, for all the new materials and electronic wizardry they pack into their next airliner programme, it is the moving parts hanging off each wing that always deliver the big step in efficiency – and therefore performance.
So when the airlines exert their pressure on the likes of Airbus and Boeing to deliver more range with lower operating costs and a competitive price tag, it is the likes of GE, Pratt & Whitney and R-R that shoulder the major burden of delivering that performance.
It should be no surprise then that all of the big three powerplant manufacturers have been struggling to deliver the sort of service readiness that Clark insists their customers should deserve. And they are often trying to achieve this at eye-watering production rates that were unheard of until recent times.
CFM International chief executive Gael Meheust points out that the engine maker is producing “40-45” Leap engines a week. P&W marketing director Paul Finklestein says the ramp-up on the geared turbofan (GTF) has been “five times as fast” as its previous single-aisle powerplant, the V2500.
“Does that mean that things we found on the V2500 in 10 years we’re finding out on the GTF in two years? [Possibly]… but the maturity rate is much, much faster,” says Finklestein. “If we had delivered the GTF on the same production path as the V2500-A1, then only about 10% of the problems that we’ve found and fixed today would have emerged.”
But the consequences of these high rates are double-edged. As the volumes of in-service engines balloon quickly, the risk of major disruption when a problem is identified can be much larger. That is a dilemma facing all the stakeholders – as many have discovered to their cost in recent years.
-Max Kingsley-Jones, London
CFM International, the Safran-GE Aviation joint venture, is powering ahead with production of its new Leap-series engines – which span the 23,000-35,000lb (102-155kN)-thrust range – as the transition away from the legacy CFM56 gathers pace.
In the first half of 2019, CFM delivered 861 Leap powerplants and 258 CFM56s, compared with respective figures of 438 and 591 for the same period a year earlier. The joint venture is on target to ship 1,800 Leap engines this year, as narrowbody production continues at record levels.
Lower 737 Max production rate has allowed engine maker to tackle supply-chain issues
That output rate has been maintained, relatively speaking, despite the problems with Boeing’s 737 Max, which is exclusively powered by the Leap-1B. Although the re-engined single-aisle has been grounded since March, production has continued, albeit at a lower rate of 42 aircraft per month – requiring the weekly delivery of around 20 engines – rather than the previous rate of 52 per month.
In fact, the propulsion specialist had been preparing to support production of 57 aircraft per month when flights with the 737 Max were suspended. “Of course, the ramp-up is not as high as we were expecting at the beginning of the year, but it is temporary,” says Safran chief executive Philippe Petitcolin. “The day the airplane is back in the air Boeing will be pushing us back into production ramp-up.”
However, the gentler ramp-up has enabled CFM to get on top of supply-chain issues, notably with forgings and castings, which slowed production of both in-service Leap variants at the end of 2018. “Production which is not growing at the level we were expecting means we have less pressure coming from our supply chain to meet our demand,” says Petitcolin.
Although minor “issues” continue to crop up, he says, over the “last two to three months” there has not been “huge pressure coming from deliveries of forgings and castings that could be late”.
As of 30 June, 44 airlines were operating 454 Leap-1A-powered Airbus A320neo-family jets and had accumulated 3.3 million flight hours; the Leap has a 61% market share on the re-engined narrowbody, says Safran.
Meanwhile, at the point the type was grounded, 54 airlines were flying 389 737 Max jets, which had amassed 1.7 million flight hours. Petitcolin describes the Leap family as “the most reliable engine of its generation”.
-Dominic Perry, London
GE Aviation is under continued pressure to fix an issue with the GE9X’s high-pressure compressor, which Boeing says has further delayed the first 777X flight. However, the Evendale, Ohio-based engine maker insists it has fixed the issue and is preparing to conduct additional tests, while Boeing has shifted the 777X’s first flight into early 2020.
GE9X development apparently progressed relatively smoothly through much of the programme, although during earlier testing the company did redesign a “stator vane lever arm” to address faster-than-expected wear. The company says the huge turbofan broke a thrust record for commercial aircraft engines several years ago when its engineers measured 134,300lb (597kN)-thrust. The engine has accumulated some 400h of flight testing, GE says.
But a major issue became apparent at the Paris air show in June when GE Aviation chief executive David Joyce revealed his team was redesigning a stator in the GE9X high-pressure compressor. The issue caused hotter-than-expected exhaust gas temperature and premature deterioration, he said. “The component has been redesigned and GE is preparing for engine testing”, GE tells FlightGlobal. “GE Aviation remains aligned with Boeing on this effort.”
Boeing has announced that the 777X will first fly in the first quarter of 2020, not in 2019 as originally planned, because of the issue. The airframer says it still expects to begin deliveries in 2020, but some analysts doubt the 777X will enter service until 2021. Boeing could release more information when issuing its third-quarter financial results on 23 October.
GEnx turbofans, which power 747-8, have continued to demonstrate sales success
Public Address/Action Press/Shutterstock
Leaving these issues aside, GE has a healthy backlog, with more than 700 GE9X engines on order with eight future 777X operators, it says. The 777X has not been a massive seller – Boeing holds 344 firm orders – but the airframer and industry analysts expect commitments to materialise next decade as airlines begin their next phase of fleet renewals.
GE continues to see sales success elsewhere, having sold some 2,500 GEnx turbofans, which power 787s and 747-8s. More than 1,700 of those powerplants are now flying, GE says. GE also co-owns CFM International, which makes the Leap line of turbofans for 737 Max and Airbus A320neo-family aircraft.
Meanwhile, GE is eyeing future engine development, studying means to improve engine efficiency through advanced materials, while looking further afield at electric-based propulsion systems. Its next project remains unclear, and the company says it is studying a variety of engine architectures. But executives have hinted that GE will primarily focus on improving engine thermal efficiency – how well an engine converts chemical energy in fuel to mechanical energy. CFM’s prime competitor, Pratt & Whitney, has taken a different tack, targeting better propulsive efficiency through the use of a fan gear in its PW1000G engines.GE hints that its next engine will include more components made through additive manufacturing (also called 3D printing) and from advanced materials like ceramic matrix composites (CMCs), which can enable engines to run hotter. GE operates the Additive Technology Center in Ohio and has some 1,000 engineers and scientists working on the technology. The company has also invested $1.5 billion in the past decade on CMCs and has two US CMC production facilities.
GE says it is also “aggressively researching hybrid-electric and electric propulsion” systems for aircraft. The company is evaluating such technology at its Electrical Power Integration Centre in the UK and the Electrical Power Integrated Systems Center in Ohio.
-Jon Hemmerdinger, Boston
PRATT & WHITNEY
Nearly four years have passed since Pratt & Whitney’s first geared turbofan (GTF) entered service. Although those years brought several high-profile engine issues, P&W says it has addressed the problems and that GTFs are proving their mettle by achieving fuel-saving expectations.
Meanwhile, the engine maker continues working to reduce GTF manufacturing costs while boosting production – no easy task as the industry struggles with supply-chain shortages. “It’s delivering all of the fuel-burn savings, noise improvements [and] emission improvements that we’ve committed to,” P&W vice-president of commercial aircraft engineering Amy Comer says of the GTF. “A lot of the reliability improvements we have put into the product are really taking hold.”
PW1100G-powered A320 deliveries were paused in early 2018 after in-flight shutdowns
The GTF entered service in early 2016 when Lufthansa began operating a PW1100G-powered Airbus A320neo. P&W makes GTF variants for A220s, the Embraer E-Jet E2 family and in-development Mitsubishi Aircraft SpaceJet range and Irkut MC-21s.
As of August, 527 GTF-powered aircraft were flying globally with 38 operators. P&W’s GTF backlog stands at more than 10,000 engine orders and commitments, the company says. P&W insists it remains on track to meet 2019 delivery commitments – even though production has not hit the originally expected levels.
Just a few years ago, the chief executive of P&W parent United Technologies predicted that GTF deliveries would hit 1,200 a year by 2020. In the first half of 2019, P&W shipped 362 “large commercial” aircraft engines, a category that includes GTFs and several older-technology powerplants.
Engine issues and supply-chain shortages have challenged production. “Casting and forgings, from an industry perspective, are going to be one of the bottlenecks for a long time,” Comer says.
P&W has brought another forging press online, which is manufacturing turbine disks and compressor rotors, and expects to have forging capacity to meet demand until 2021, Comer says. Problems with accessory gearboxes, low-pressure turbines and knife-edge seals in high-pressure compressors have affected in-service GTFs. Airbus halted deliveries of PW1100G-powered A320neo-family aircraft in early 2018 after several in-flight shutdowns.
Just weeks ago, US regulators required operators to address potential oil leaks affecting the A220’s PW1500Gs and the E-Jet E2s’ PW1900G. But Comer insists: “All of the significant service interruptions have been addressed from a design solution perspective.” She says new GTFs have fixes, although some 1,000 in-service engines must be updated.
Despite hiccups, Comer says the engines are performing well, with the PW1100G’s dispatch reliability hitting 99.96%. “The engine is getting pretty close to world class in terms of dispatch reliability,”
she says.P&W’s future engines will likely include more advanced materials such as ceramic matrix composites and the company is developing hybrid-electric engines. But Comer says the GTF architecture is here to stay because it can be scaled to create new engines for narrowbodies or widebodies, including Boeing’s proposed New Mid-market Airplane.
“The geared turbofan is not going anywhere,” Comer says. “It’s going to be the core of any future product development that we do.”
-Jon Hemmerdinger, Boston
At Rolls-Royce, the big three programmes are the Trent 1000, 7000 and XWB, which are performing with varying degrees of success. On the positive side of the ledger is the Trent XWB that powers the Airbus A350. Production is matching the airframer’s requirements and the in-service performance of the powerplant is where it should be. The engine is “operating very reliably with 27 airlines around the world”, says R-R chief executive Warren East.
Available in three variants – the derated 78,900lb (351kN)-thrust XWB-75, the 84,200lb-thrust XWB-84 and the 97,000lb-thrust XWB-97 – the powerplant is a “driver” for engine flying hour growth and unit cost reduction, East says. As of 30 June, XWB engines accounted for 11% of the fleet, with this only set to grow as the “largest-volume engine coming out of Rolls-Royce over the next several years”. Breakeven is forecast by end-2020.
Trent 1000-related groundings should largely be resolved by end of second quarter 2020
With the A330neo-powering Trent 7000 – the exclusive powerplant for the re-engined widebody – things are also looking up after an initial slow start. Service entry for the long-haul twinjet was delayed by hold-ups to the programme in late 2018, but during the first half of 2019, R-R shipped 54 of the engines to Airbus, a performance East describes as a “big turnaround” for the programme. R-R is now “comfortable” with its status, he says.
With only 26 A330neos in service, operational feedback and reliability data is limited, however.
But causing the most sleepless nights in Derby at the moment is the Trent 1000 for the Boeing 787. While R-R now appears to have a better handle on the premature deterioration issues that have plagued the engine, disruption for operators is continuing. This was illustrated by an August incident in which parts from a Trent 1000 were scattered over Rome when two intermediate-pressure turbine blades fractured.
Although R-R had promised that the number of aircraft grounded as a result of the issues with turbine and compressor blades would be in single figures by year-end, it has since revised that to the second quarter of 2020. Package B and C engines are affected, as well as the Trent 1000 TEN, the newest variant of the powerplant.
For R-R and its customers, the fear had always been that the problems on the Trent 1000 would also manifest on the XWB and 7000 models. But speaking in late May, R-R chief customer officer Dominic Horwood said that the blade-deterioration issue had not been seen on other engines. “We are confident that what we are dealing with on the Trent 1000 are design issues which are unique to that product and they are related to the specific configuration, the specific design of that engine at a component level,” he says.
Horwood says that lessons learned from the experience are being incorporated into the manufacturer’s design and testing processes for the future, including a better understanding of the corrosive sulphidation process at the root of the blade cracking.
-Dominic Perry, London
When Chinese airframer Comac’s C919 was still being developed as a competitor to Boeing’s 737 and the Airbus A320, much was said about a “home-made engine” for a home-grown aircraft. But more than two years later, the fanfare has died down, even as the C919 continues test flights and looks poised to enter service with Chinese carriers – minus the Chinese engines, for the time being.
The prototype of the CJ-1000AX, the alternative powerplant manufactured by Chinese engine maker AVIC Commercial Aircraft Engine (ACAE), was first publicised in December 2017, after 18 months of assembly. ACAE had signed a deal with Comac a year earlier to supply engines to the narrowbody programme.
The CJ-1000AX was touted as the “home-made engine” by the state-owned Global Times newspaper that would “replace imported foreign engines in future”. The C919 will initially be powered by CFM International Leap-1C engines.
Last May, the CJ-1000AX hit a milestone in its development when it achieved power-on. The high-bypass-ratio turbofan engine’s core reached a maximum speed of 6,600rpm, according to Chinese officials.
Early versions of C919 will be powered by Leap-1C
FlightGlobal has previously reported that China plans to build 24 more CJ-1000 prototype engines to support an airworthiness campaign, with entry into service targeted after 2021.
Citing an Aero Engine Corporation of China (AECC) researcher, Global Times painted a bright future for the turbofan: “The CJ-1000 is designed for the C919, but is expected to power the Boeing 737 or Airbus A320 or a similar newly built aircraft in the world market by 2025.”
Meanwhile, the AEF3500 – formerly known as the CJ-2000 – was first unveiled at the 2018 Airshow China in Zhuhai. The turbofan was pitched as a Chinese engine alternative for the Sino-Russian CRAIC CR929 widebody programme. Little is known about the status of the AEF3500, but media reports suggest it could be put into service on the CR929 by around 2030. Similarly to the C919, the CR929 could enter service in 2025 powered by western engines, before a Chinese-made option is offered a few years later.
It could, however, face competition from Russia in the form of Aviadvigatel’s PD-35-1. In January last year, United Engine and Aviadvigatel were picked by Moscow to develop the demonstrator powerplant.
While AECC continues with work on the two engine types, the aircraft they were supposed to power are moving on with development. It remains to be seen if China can strike a double win with domestically manufactured engines on a home-grown aircraft.
-Alfred Chua, Singapore
Russia’s most significant civil aircraft engine programme centres on the Aviadvigatel PD-14, which is set to be fitted for the first time to the Irkut MC-21 twinjet. Three flight-test examples of the MC-21-300 have been produced while a fourth has been assembled, says Irkut, and is now undergoing systems fitting. All four are powered by Pratt & Whitney PW1400Gs.
But Irkut is intending to offer the PD-14 as an option for the aircraft. It disclosed earlier this year that it would modify the first serial-production MC-21 for flight tests with the PD-14. The powerplant obtained Russian certification from regulator Rosaviatsia in mid-October 2018, after airborne tests on an Ilyushin Il-76, and efforts are under way to secure validation from the European Union Aviation Safety Agency.
Named for its 30,800lb (137kN)-thrust capability, the PD-14 features a three-stage low-pressure compressor and an eight-stage high-pressure compressor, linked to a two-stage high-pressure turbine and six-stage low-pressure turbine. Mock-ups of the powerplant shown during the MAKS Moscow air show in August featured composite nacelle assemblies, hollow titanium blades and other technologies. Twenty new materials,
such as monocrystalline alloys were developed for the PD-14, according to state materials research institute VIAM.
No first flight date has been fixed for the PD-14-powered MC-21. But domestic engine production for the type – as well as production of the aircraft itself – has become an important issue in the wake of US materials sanctions. Russian deputy prime minister Yury Borisov pointed out earlier this year that, if necessary, the manufacturers would be “ready to switch only to domestic engines”.The PD-14 is intended to be part of a family that would extend to the high-thrust PD-35, potentially for the CRAIC CR929, and projects including a possible Il-96 modernisation. Proposed lower-thrust versions include the PD-10, aimed at powering a “Russified” version of the Sukhoi Superjet 100, which is currently equipped exclusively with the Franco-Russian PowerJet SaM146.
The 15-year-old joint venture recently reached 400 engine deliveries for the Superjet programme since the first in August 2010. Total operating time for the powerplant exceeds 1.3 million hours, says the manufacturer, with one “flagship” example on a Yakutia Superjet reaching over 9,600h.
PowerJet has worked to expand customer support for the engine, with creation of special pools of spare engines and components and the extension of repair capacity in Russia and France. “More than 20 engines can be [accommodated for] repair simultaneously,” it says.
Sukhoi Civil Aircraft says the total number of Superjets delivered by the end of June this year reached 162 aircraft.
-David Kaminski-Morrow, London
‘Russified’ version of SSJ100 could be powered by a proposed PD-10 unit