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Working On The Production Line: GE Aviation

by Taylor

13th Novemeber, 2015

The steam rising from the test bays indicates that an engine is being run in the bay.

Before going to work at Epic I spent the entirety of my professional career (which consisted of a cumulative 21 months of internships and co-ops) in the aviation industry. I enjoyed it too. I first worked with Wright Patterson Air Force Base in Dayton, OH-famous for the top secret flight programs and its supposed involvement in the 1947 Roswell, NM incident. Many of its top secret programs have reportedly been moved west as the surrounding city gradually encroached on the base.

At Wright Patterson I worked as a part of the civilian (colloquially known as “outside the gate”) Tec^Edge student research program, designing a tool to help first responders manage disasters by pulling data from social media. We built a command center (known as “Eagle Eye“) that displayed information (largely tweets) surrounding a specific event and calculated a score predicting whether or not this event had occurred or will occur. Each data point had associated geographic coordinates and we pulled those onto a Google map displayed in the command center console. If first responders went out on the scene, these coordinates were overlaid on a HUD using augmented reality to identify where the tweets were posted from.

At the end of the summer we delivered a rough copy of our project to the program and I left to begin my Fall co-op at GE Aviation‘s headquarters in Evendale, OH. This was an extremely interesting experience.

GE Aviation is a (unsurprisingly) subsidiary of General Electric, one of the most successful companies in the history of the world. It is a Fortune 8 company, with more than $ 148.589 billion (2014)[2]in revenue. Before I get into examples of life at General Electric, let’s get a few facts straight.

General Electric

FoundedSchenectady, New York, U.S. (1892; 123 years ago)
Founder
Products
Revenue US$ 148.589 billion (2014)[2]
Total assets US$ 648.162 billion (2014)[2]
Number of employees
305,000 (2014)[2]
Subsidiaries

General Electric’s long history of innovative achievements (including direct current, a reliable light bulb, the first radio broadcast–a precursor to NBC, the refrigerator and the jet engines on the first U.S. jet fighter) and its outstanding brand recognition make it an attractive company for aspiring engineers to work for.

GE’s development programs (EEDP, OMLP, ITLP, FMP, among others) are seen as best-in-class and serve as the example of many other companies across the globe. These well-regarded programs and established brand name paint the picture of a wonderful company with a great workplace environment.

For the most part this is the case. In my first rotation as a co-op at GE Aviation I worked in Marine & Industrial Assembly Quality.

Marine & Industrial Assembly Quality

Jump to 0:25 for an explanation on “Suck, Squeeze, Bang, Blow”

That’s a lot of words, so let’s break that down a bit. GE Aviation Marine & Industrial (M&I) essentially means “jet engines that don’t fly”. Jet engines at the most fundamental level work the same way as any other kind of engine or generator–they “suck, squeeze, bang and blow”. In the suck phase, they take in an immense amount of air (the GenX has a fan diameter of 111.1 inches and can take in 2658 pounds-mass of air / second); squeeze the engine compresses the air through a series of stages–making the particles hotter and moving faster with more energy; bang–here the engine injects fuel and combusts the the compressed air; finally blowing out the air with massive energy (the GenX with an impressive 76,100 pounds of takeoff thrust).

The energy output of these engines can be used for things other than flight, and this is where M&I comes in. Marine and Industrial takes the same fundamental engine design, swaps out the expensive, lightweight yet high-tensile metals (think: titanium, nickel or aluminum alloys) and replaces them with much cheaper, still high-tech pieces of metal that are better suited for the ground (they weigh more). M&I engines like the LM2500, the LM5000 and the LMS100 can be found in naval warships and various cities throughout the world. Russia leased two LMS100‘s to generate power for the 2008 Sochi Olympics.

So you’ve got the idea, Marine & Industrial creates non-flying turbines, roughly based on their flying equivalents. On to Assembly Quality.

Assembly Quality was the title of my role on the manufacturing floor. Even though I was a computer science major, I was placed in a quality role with one other co-op student from Puerto Rico. Our responsibilities were broken up by engine program, I handled the LMS100, LM2500, and LM5000, while she handled the CFM, and CF6 programs. Because M&I was in a different building (Building 800–adjacent to mine–building B) from the CF- and other flight engine programs, we didn’t interact too much, that’s okay though because I had my hands full.

My main role entailed of parts disposition. I would take damaged manufacturing parts from the crib (a 15′ x 18′ room) pull up their specifications, and measure the damages against the parts. If the damages fell out of spec, then the part had to be scrapped. If not, then I had to find a way to get it back out onto the floor (this was not easy).

Because Evendale is a unionized shop, there are many restrictions as to what non-union employees can do. For instance, I was the only non-union employee allowed to touch shop parts. I was only allowed to touch them within the M&I crib. So if I wanted to get a part from the crib back out onto the floor…I had to do some favors.

“…I ain’t touching that shit”

I’ll never forget my first day, I had just dispositioned a part, and a shop worker came into the crib to wipe his hands. (There was always a large role of paper towel there so this was not uncommon). I had a shelf where the dispositioned parts lie, and as the worker was finishing I asked– “mind if you take this back out onto the floor?”

He paused and stared at me as if I had just insulted his family and said “…I ain’t touching that shit” and walked out. My first experience in dealing with unions could not have gone more poorly.

Going forward I was nervous enlisting the help of others, but I knew I would not succeed at my job if I did not make friends with the guys. (Plus–I wanted to be friends with them–who wants to work in a hostile workplace? The whole union, non-union divide felt to me like an uninspiring 21st century telling of Romeo & Juliet with each side taking on the role of a Montague or Capulet.)

So I eventually made it in with the guys, and several of them became the guys I most connected with in the shop. I got into a rhythm and soon was able to take on more than the simple dispositioning of parts. Each afternoon I would bug the forklift guys that stocked parts to come pickup pallets that were full of “return to stores” parts (parts that were damaged but whose dents fell within spec and could be reused). In the morning I would swing by the guys at the stator case station and chat. Kelly would tell me stories of his family and give animated accents of those that still lived in the Appalachian mountains of eastern Ohio. Glenn would tell me the dirt on any of the employees in the shop or regale me with a favorite story of his. A few of the more interesting ones (below).

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Interesting Stories

  • In the 80’s, the shop was wild and poorly managed. You could see employees driving down the aisles in forklifts with empty fifths of liquor in their hands. There were only a few women in the shop at that point. One of the women was supposedly sleeping with the floor supervisor at the time–a suspicion that could be easily confirmed by watching the two head into the supervisors office for up to an hour at a time. The floor supervisor was in charge of determining who is doing what and he would often give her poor assignments. One day she tired of this and in the morning shift switch she yelled at him in front of the rest of the employees–“you may be able to f**k me in there (pointing to his office) but you won’t f**k me out here!” and walked out.
  • In the early 2000’s GE shut down building D, which was at the edge of the Evendale campus. Rumor has it there was a radiation problem due to the experimental nuclear engines GE was developing in the 70’s. The point behind these was to allow for longer flight for planes like Air Force One and other mobile command units. The reality is that this piece of land was likely affected from Radon (a naturally occurring element in Ohio soil), as the nuclear engines never got past the conceptual stage (aerial refueling became standard and fuel prices plummeted in the 80’s). As part of the teardown process they were moving the containers we ship engines in (stored near building D) and in the moving process they saw one much older, rusted looking container. Upon opening it they were surprised to find an engine in the container! The next day Glenn showed up to work and saw a number of security and engineers posted outside the engine container. Turns out GE had developed a top secret engine for the military a few years prior, and then lost it.
  • In the 80’s, GE developed a new type of engine which it called the “unducted fan” or UDF. Essentially this was a high tech prop fan. It was so high tech in fact that it is 20% more efficient than conventional jet engines, even those of today. In 1988, GE fashioned its UDF to a regional jet and flew it across the Atlantic ocean to the Paris Air Show to reveal the increased fuel efficiency of the UDF. Customers considered the exposed blades a safety hazard (although unfounded) and fuel prices plummeted shortly after the demonstration, making the UDF unmarketable. It’s pretty amazing how something is out there today that could shave 20% of airline fuel costs and yet they choose not to utilize it.

A prototype unducted fan. The UDFs are substantially more efficient than conventional jet engines. The propeller blades are exposed rather than contained in a nacelle. Designed in the 80’s, this engine was added to a regional jet which was subsequently flown to the Paris Air Show as a testament to its fuel efficiency. Its announcement coincided with a plummeting of fuel prices, causing airlines not to purchase them. Customers prefer the contained blades and as such jet engines run 20% less efficient than they need to.

Interesting Work

The coolest thing about working on a jet engine assembly line is simply that–you’re working on a jet engine assembly line. Jet engines are very cool machines and they’re something every boy (and perhaps girl) wants to grow up flying. So even mundane tasks can be interesting when they end with “[Do this] for the jet engine”.

Quality Investigations

The J79 engine was the first Jet engine to use Gerry Neumann’s variable stator vanes and an enormous commercial success for the company.

As my responsibilities grew I got to work on quality investigations with my boss–determining what was causing dilapidation of the ceramic casing on our variable stator vanes. Variable stator vanes, as a side note are an invention of Gerherdt Neumann and are the key to giving GE the competitive advantage over Pratt & Whitney and Rolls Royce. The patent describes the problem VSVs solve,

In order to obtain more efficient performance from an engine, it is very desirable to have a high pressure ratio compressor for the engine. However, whenever a high pressure ratio compressor is used, stall characteristics occur during various stages of increasing speeds.

To efficiently run an engine you want to have highly pressurized air. However during takeoff you do not need to move fast, you need to move powerfully, to get off the ground. Pratt & Whitney overcome this challenge by releasing, through the use of actuators, a small portion of the compressed air at each stage, decreasing the pressure but pulling in inefficiencies as a certain amount of air and work done by the compressors is lost at each stage. The variable stator vanes change the angle at which they are positioned during axial rotation and therefore simply “do less work” while still maintaining the same RPM.

This investigation was an interesting peek into the human psyche. One thing to note–almost everyone hates quality. If a shop worker has to interact with quality, they likely are getting in trouble. That may not always be the case, but when going around the shop and asking questions about the lifecycle of the VSVs throughout the shop, everyone is irritated and doesn’t want to answer questions. Why? They’re worried you’ll find fault in their work and they’ll be blamed for damages. I found the LMs100 vanes were being held in the LM2500 container and this caused them to occasionally touch one another as the container was not built for the larger vanes. The solution was “simply” to recruit the shop carpenters to create larger containers for the blades–something that I was not able to get done before leaving as they had a long list of work to do, and an intern’s request was at the bottom, or near bottom of the totem pole.

Quality Improvement

Just as Building D was shut down, Building B too was being shut down. Slowly. Egregiously slowly. So slow in fact that we, GE Aviation, a company with unheard-of amounts of red tape, were able to change manufacturing processes to account for the building tear down. The tear down of Building B posed a number of threats to engine production, and I was tasked with quelling one of them. The engine goes through a number of stages in its build process. At some points it is built while standing vertically on its stator case (Vert), and other points it is hanging horizontally (Westmont–named after the company that built the metal support from which the engine hangs). When in Westmont, there is a short period where the mid-fan shaft is installed. During the installation of the mid-fan shaft there are exposed ball bearings. Since some of the engine stages had been moved to building 800, the engine had to be transported between the buildings. During the transportation of the engine the mid-fan shaft was covered with a trash bag (and masking tape) to protect it from dust particles. This was not deemed the safest practice, nor the greenest. (The latter was of surprising importance to the company.) I got to design a resusable mid-fan shaft cover that was made of a thick rubber tarp material and accounted for two possible production states states of the mid-fan shaft. These covers were to be used before the installation of the mid-fan shaft and before the installation of the high pressure / low pressure combustors. It was a pretty rewarding experience to leave the internship with a part number to my name!

Shop Floor Database

The stages the rotor goes through. Each white divider represents a major stage change. Engineers use the database to ensure each engine moves through the line on time and to plan to divert other engines to different stages if not.

The project with the greatest impact to the shop was a Microsoft Access database built by a few interns and me.

A major issue in Assembly is communication. Any time that an engine is sitting idle, waiting for a machine to be available is time and money wasted. Leveraging that knowledge and my understanding of the existing processes engineers & mechanics used to keep engines moving through the shop floor, I (with the help of another intern, Andrew Perkins) built a real time status board of the jet engines currently being built on the shop floor. This replaced individual sheets of paper the process engineers were using to keep track of their engines and instantly updated the other engineers of the engine progress. This enabled employees to make informed decisions based on the progress of each engine, drastically cutting down on time from build start to shipment. Unfortunately I do not have the numbers backing up the jump in productivity, but it is worth noting that GE found the project valuable enough to order over $100,000 worth of hardware placed throughout the manufacturing floor to fully support and display the status board on.

JETS

JETS is an acronym for Jet Engine Teardown School. It is an extremely competitive offering, taught by Cincinnati State community college in the basement of GE’s Building 800. JETS was taught 6 hours a day over the course of 5 days in which we learned the fundamentals of jet propulsion. This was an absolute amazing experience and I am so thankful to my manager Jack White for his willingness and support in getting me into the class. Others flew around the world coming to take the course and I was one of only a few at GE that get the opportunity. We got to rebuild old CF34 engines which are capable of up to 20,o00 pounds of thrust (pending the configuration and the model). According to the instructor, they used to build on an older model of engine (I believe earlier than the J79) and they actually let students run the engine. They would bolt the engine to a cement block in the parking lot and turn it on and run it. Unfortunately someone parked just a bit to close (or the engine was built just a bit too well) and a car’s paint was melted off. That incident coupled with the fact the CF34s have a much greater magnitude of thrust prevented my class from doing the same.

JETS – Jet Engine Teardown School is a special program that lets engineers build their own jet engines. Many employees came from around the world including a team from SNECMA to take the class. I was the only intern.

That’s a few of the more interesting stories about life on the GE Aviation assembly line.

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by Taylor