Inside the World’s Largest Engine Test Cell By Thom Patterson
AEROSPACE TESTING

Inside the World’s Largest Engine Test Cell By Thom Patterson

The new engine test facility at the Atlanta, Georgia-based Delta TechOps opened earlier this year. It is, at present, the largest engine test cell in the world. It is designed to accommodate the most powerful engines currently in service, as well as future engines not yet designed or operating.

The moment you step inside the world’s largest engine test cell at Delta TechOps in Atlanta, it’s clear you’ve entered a room specifically designed to handle the next generation of turbofans. Opening for business last February, this $100-million facility is every bit as big, complex and sophisticated as the engines that pass through it.

How big?

To enter the main test chamber, we venture somewhat awestruck through a pair of automated, four-story-tall, 26-foot-wide concrete doors — each weighing more than 300,000 pounds, or 136,000 kilograms. The chamber itself measures about 14.6 meters high by 14.6 meters wide — or 48-by-48 feet. Its bright white walls are dotted with LED lights, reflecting off a pristine concrete floor. One wall consists of a huge filtering screen. During tests, air flows through the screen from an adjacent intake chamber that channels air from outside into the building.

The main chamber of the test cell is rated to test engines with up to 150,000 foot-pounds of thrust.
The main chamber of the test cell is rated to test engines with up to 150,000 foot-pounds of thrust.
A technician monitors mulitple display screens during tests.
A technician monitors mulitple display screens during tests.

Appropriately, everything inside the main chamber is dominated by the engine. An over 16,000-pound Rolls-Royce Trent XWB hangs 40 feet overhead, mounted to a steel thrust frame, which itself is bolted directly to the building’s I-beams.

If that sounds a bit extreme, keep in mind this facility routinely runs engines that approach 100,000 foot-pounds of thrust. You want to be double sure the engines don’t get away from you. Think of it like wearing a belt and suspenders to keep your pants up.

Next-gen engines are key to providing fuel-efficient and cleaner-burning power for new and developing airliners. Airlines will rely on these improvements to help maintain profitability into the future. Delta’s new test cell was born from a need for new MRO facilities specifically designed for these new engines.

Designed and built by Aero Systems Engineering (ASE), the cell is built to handle engines that haven’t even been built yet ­­— with more thrust than current engines can produce.

In fact, it’s rated to withstand up to 150,000 foot-pounds of thrust. That’s 35,000 foot-pounds more than the world’s most powerful turbofan currently in service: GE Aviation’s GE90 — which powers Delta’s Boeing 777-200LRs.

Typically, when an engine comes through Delta TechOps, technicians disassemble it, inspect it, repair it and reassemble it. Finally, it goes into the cell for testing. If it doesn’t pass muster in the test chamber, the engine goes back to Delta’s engine shop for additional scrutiny.

All four of Delta’s engine cells together test an average of about 1-4 engines daily – with the 2019 annual total expected to be around 725.

Control Room

Much of the testing work is performed inside the cell’s Control Room, located up a metal stairway and through a heavy door just a few feet from where the engine is mounted.

Inside, a lead technician sits at a Yanos Aerospace control board, keeping a constant eye on multiple display screens, including live video, showing multiple angles of the engine as well as real-time performance data.

The technician brings the engine to life, allowing air to flow from outside the building into the main cell chamber through a 66-feet-tall adjacent intake room.

As the controlled air moves through and around the engine, a team of three or four technicians begins monitoring and recording multiple data metrics, including air pressure, oil pressure, oil temperature, vibration, fuel consumption, fan revolutions and thrust.

The tech initiates a so-called “snap accel” – a quick acceleration test aimed at finding potential anomalies and signs of possible mechanical problems. He pushes forward on a bright silver thrust handle located on the right side of the control board. The mighty machine gains thrust and moves the needles on the display, indicating rising oil and fuel pressure inside the engine and increasing internal rotation speeds.

Delta’s cell is focused on efficiency. They’re basically in and out of that test environment as fast as possible so they can get those engines back on wings.

Knowing that a concrete wall is all that stands between us and a raging machine blowing 84,000 foot-pounds of thrust is – well – kind of a thrill.

Each engine undergoes a battery of tests before it leaves the cell and returns to service, including weather simulation programs that analyze engine performance during heavy winds and other situations.

Exhaust Stack

The engine exhaust along with the jet blast are funneled out the main chamber through a long tunnel located behind the engine, called an augmentor tube.

The tube then shepherds the exhaust to a metal “blast basket” suspended inside the cell’s 78-foot-high, 23.7-meter exhaust stack.

As we stand inside the bottom of the exhaust stack, we realize that here, the engine’s super-heated exhaust often reaches temperatures approaching 800 degrees Celsius, nearly 1,500 Fahrenheit.

Obviously, you don’t want to be standing here during a test.

The blast basket above us quickly cools the violently turbulent exhaust air as it begins to rise toward the top of the room.

Hanging high above the basket are multiple six-feet-tall, two-feet-wide devices called exhaust bar silencers. They’re made of special acoustic materials that absorb sound from the engine — which helps to limit aerodynamic noise pollution outside the building.

Global Customers

The location of Delta TechOps’ massive headquarters, adjacent to a taxiway at Hartsfield Jackson Atlanta International Airport, dates back to 1960, when the company broke ground on a facility to maintain its first fleet of jets – McDonnell Douglas DC-8s and Convair CV-880s.

According to the annual Oliver Wyman MRO Market Forecast 2019, the pace of growth for engine MRO will have some ups and downs over the next decade. “In the first five years, new engines are expected to lengthen the interval between shop visits with less need to replace life-limited parts and to conduct other scheduled maintenance,” that forecast predicts. They go on to say that the newest generation engines are more fuel-efficient but are using more expensive materials and more complex technologies that “can be quite expensive to replace or repair when the time comes.” Regardless, most engine shops are full right now and seeing unprecedentedly good times.
According to the annual Oliver Wyman MRO Market Forecast 2019, the pace of growth for engine MRO will have some ups and downs over the next decade. “In the first five years, new engines are expected to lengthen the interval between shop visits with less need to replace life-limited parts and to conduct other scheduled maintenance,” that forecast predicts. They go on to say that the newest generation engines are more fuel-efficient but are using more expensive materials and more complex technologies that “can be quite expensive to replace or repair when the time comes.” Regardless, most engine shops are full right now and seeing unprecedentedly good times.

Nearly 60 years later, Delta TechOps maintains its own fleet of more than 900 airliners along with aircraft owned by more than 150 customers, including Hawaiian Airlines, Virgin Australia and UPS, as well as military and government planes. It has committed its new test cell and engine shop to maintain more than 7,000 engines through the next 30 years.

The airline has grown its MRO business so that it ranks among the world’s biggest, boasting 11,000 technicians, engineers and inspectors spread out across 58 maintenance stations.

Delta’s new test cell is the first to be built by a U.S. airline in more than 20 years, according to the airline. The idea began when executives recognized the market was calling for additional MRO capacity in the next-gen engine space.

Back in 2015, a ground-breaking deal between Delta and Rolls-Royce provided the trigger to move the idea forward. Under the agreement, Rolls-Royce designated Delta TechOps as an Authorized Maintenance Center. In 2018, the relationship expanded to include on-wing services.

Mike Moore, Delta TechOps senior vice president of operations, inventory and logistics, says the facility is the result of years of contract negotiations.

“If it wasn’t for deals that we signed with Rolls-Royce and we subsequently signed with Pratt & Whitney, we wouldn’t have been able to build this facility,” Moore says.

Now, nearly a year after opening its doors, Delta’s new test cell is actively servicing Rolls-Royce Trent 1000 models, following completion of production tests.

In the coming months, production tests and servicing will follow for other types, including Rolls-Royce BR715s and Trent XWBs, as well as Trent 7000s, which power the new fuel-efficient Airbus A330neo widebodies.

The facility also plans to handle Pratt & Whitney’s PW1100 and PW1500 Geared Turbofan engines, which power two new Airbus single-aisle jets: the A321neo and the A220-100.

Rising MRO Earnings

The future for Delta TechOps looks bright. The new test cell and engine shop are expected to result in $1 billion in MRO growth over the next five years.

“We’re expecting growth around the engine space over the next two decades,” says Moore. “And this facility allows us capture part of it. It will be a key part of our growth, going forward.”

Delta wouldn’t share breakout earning figures for the test cell separately, but during a quarterly earnings conference call on October 10, Senior Executive Vice President and Chief Operating Officer Gil West revealed that Delta’s MRO business so far in 2019 was up about $120 million ­— about 23% more than 2018.

West said he expected the next few years would yield benefits from “the investments that we’ve made in terms of capacity from new generation engines, in particular the Rolls Royce Trent engine and the Pratt & Whitney Geared Turbofan.”

In addition, test cells like Delta’s stand to gain from the mountains of performance data generated by next-gen engines.

“By having more of this information, it will allow them to have better visibility into which airline engines are likely to come off in the next 3, 6 or 12 months and in what conditions those are, so they can better plan their capacity and better plan their supply chain in support of that,” says Dan Leblanc, Principal at Oliver Wyman, and a former Pratt & Whitney structural analyst.

Bigger Test Cell

MDS Aero Support, a Canada-based, privately-held corporation is currently building a larger turbofan engine test cell facility for Rolls-Royce in Derby, England.

When completed in 2020, not only will the facility be fully equipped with the latest testing technology, at 7,500m² (80,730ft²) it will be the biggest of its type in the world.

The new test cell, designed and built by MDS, will serve as a laboratory for Rolls-Royce to develop their next generation turbofans, including the company’s UltraFan engine.

“Delta’s cell is focused on efficiency,” says Joe Hajjar, MDS vice president of business development. “They’re basically in and out of that test environment as fast as possible so they can get those engines back on wings, but the new Rolls-Royce facility will be focused on research and development, where test engineers will push the engines to their limits while collecting as much data as possible.”

“Typically, we’ll measure 3,000 – 5,000 measurements, some at over 100 times a second, with less mature engines, whereas a service facility may measure 150-300 measurements with certified engines,” says Hajjar. “So you can see the objectives and challenges are quite different between an experimental test cell and a cell for MRO operations.”

We believe we’re changing the game in terms of giving the OEMs the ability to measure a lot of data very, very accurately and very quickly.

As part of a wider company investment of £150 million, or about $194 million in UK aerospace facilities ­— Hajjar says the new Rolls-Royce test cell will be outfitted with the most advanced technologies, including the ability to inspect internal engine components via X-ray imaging. The facility’s walls will measure 5.5 feet or 1.7 meters thick.

Based in Ottawa, MDS Aero Support boasts over 500 people across its various subsidiaries and support offices — helping to make it among the world’s largest firms that both operates and designs and builds multi-million-dollar testing facilities across the aviation and industrial sectors.

“With both test operators and designers under one corporation, we have a unique perspective of our customers’ needs and we continue to invest in testing technologies that help our clients produce better products,” Hajjar says. “We also recognize the investments our customers make are mission critical, and they require the most advanced solutions to ensure they have accurate and reliable data.”

“At MDS, we believe we’re changing the game in terms of giving the OEMs the ability to measure a lot of data very, very accurately and very quickly,” says Hajjar. “We’re talking about a new IT-based technology that we developed to measure an aggregate of a million channels every second with zero loss, and absolute certainty.”

Growth Drivers

Although there currently are only a handful of comparable large turbofan test cells like Delta’s, industry experts predict more will be built — especially in Asia — where more aircraft are on order than are currently in service, according to IATA and Flight Global.

Although ASE built China Airlines a new test cell a decade ago in Taiwan, its thrust rating is 120,000 foot-pounds – 30,000 foot-pounds less than Delta’s.

Korean Air opened its large test cell in 2016 in Incheon, South Korea. The cell, also built by ASE, measures 14 meters by 14 meters – slightly smaller than Delta’s, but rated the same: 150,000 foot-pounds.

Ultimately, overall growth in the number of test cells will be determined by engine manufacturers.

“They want to maintain a proper balance of test capacity, MRO services and parts supply in order to service the airlines at optimum efficiency,” says David Marcontell, senior vice president at consulting firm Oliver Wyman CAVOK. “As more large engines are delivered and on wing, there will be a need for more capacity.”

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