Extreme Engineer of the Month

Profile: Shawn Warren, Aerospace Engineer, GE Aviation

GE — Aviation
Lead Engineer — DFSS BB
Commercial Rotating Parts Engineering — CF34/CFM56 Design

Education:

• B.S. Mechanical Engineering, Penn State University
• Currently working toward Master's in Engineering at the University of Cincinnati. Among the courses Shawn will take in his masters program are advanced propulsion 1 and 2, elasticity, vibration, and a combustion course focused on aircraft.

Favorite Classes: Shawn's favorite classes were those that pushed him the most and were the most challenging:

• Thermodynamics
• Heat Transfer
• Fluid Dynamics

Best Skills: Shawn lists his best skill as his unwillingness to accept failure. He is very goal driven. In school if he said he was going to get an A in a class, he'd do it no matter what it took. He applies that same work ethic and approach to his career.

Hobbies: Spending time with his children, golf, playing in a basketball league, and coaching his son's football team.

Role Model: Shawn particularly admires his mother—her strength, determination, and leadership.

Advice: Don't be scared of engineering. The classes are hard for everyone—even the smartest people. Don't be afraid to ask for help. The smart people are those who get that extra help. Make sure you get off to a good start; it's easier to maintain a good GPA than fix a bad one. Go after different experiences. Variety of experiences will make you a better engineer and give you a broader perspective.

Shawn’s interest in engineering dates back to middle school when his mother signed him up for a week-long engineering program for minorities at Clarkson University in Pottsdam, NY. It was one of those great programs where you build bridges and participate in team building exercises. That did it for Shawn. His focus became engineering, and as a result he attended Brooklyn Technical High School, which gave him a solid foundation to pursue engineering in college.

From Bridges to Mechanical Engineering

Because of all the great bridges in New York State, Shawn had decided to choose civil engineering as his focus and selected Penn State and Rensselaer Polytechnic Institute as his top choices for college. Due to a paperwork snafu, his acceptance at Rensselaer was delayed coming in, so he accepted admission to Penn State. There he was encouraged to choose mechanical engineering for his scholarship, having been told that you can do just about anything with a mechanical engineering degree. He had a passion for learning how things work, so it seemed like a good fit.

The Most Rewarding Classes….the Most Challenging

The classes he liked the best were those with professors who pushed him to do his best. They weren't always the easiest courses, but for Shawn, they were the most rewarding. Most importantly, they helped him to focus in developing his problem solving skills, the main engineering skill he learned.

Internships… and Co-Ops—Gaining the Broad Perspective

From DOT to Merck to 3M

Shawn peppered his collegiate curriculum generously with co-op work and internships. His first internship was as the U.S. Department of Transportation (USDOT) on assignment with the Federal Railroad Administration. Here he worked on the merger of two major railroads, assessing the environmental and traffic impact.

Next, he worked for Merck, the pharmaceutical giant, for two summers on their Y2K Compliance Program. With the turn of the millennium—the year 2000—all computer programs with date fields had to be reviewed and updated. This included programs that oversee and operate equipment in the plants as well as those used on PCs and mainframes in corporate offices. At that time most programs were written with only two digits for the year. Getting a 00 in the year code would create logic errors and crash many programs.

Shawn worked at Merck to check equipment in plants for programmable logic control fields. In addition to the problem solving skills of an engineer, he got an opportunity to apply management skills. Much of the internship was spent making presentations to program managers, which gave him a broader feel for what engineers do.

During his third summer, Shawn was a facility manager at Merck, where he was responsible for union workers and had to learn to balance cordial relationships with his crew with management responsibilities. In addition, he learned about the strict limitations of a union shop. As a non-union member he couldn't even pick up a tool.

Shawn’s next three co-op assignments were with 3M in Minnesota. Here he worked in research and development on developing new technologies for generating nonwoven materials.  His next assignment was process improvement for one of the production lines. This gave him experience with Six Sigma and quality process improvement. His third assignment there was in the automation group for Post It tabs. This robotics-based assignment ended up being his favorite, as it catered to his curious nature.

The Accidental Aerospace Engineer

Looking at Shawn's co-op and internship experiences, it's hard to connect the dots and get an aerospace engineer. However, Shawn dropped off some left over resumes at the GE table during a career fair he attended. At the time, he didn't realize GE made anything other than refrigerators and light bulbs. To his surprise he was called for an interview with the GE Aviation division, which makes aircraft engines. He was amazed at what they had to offer. At GE he would participate in their Edison Engineering Development Program, which rotates young engineers through a variety of field assignments to see where they fit best. It also incorporates getting a master's degree with time off work for classes. He was impressed with the program, but the clincher for Shawn was the model of an aircraft engine in the lobby. He was amazed at its complexity and how its parts work together with control systems and other elements of the aircraft. He couldn't imagine how engineers designed such a complex piece of equipment in the 1950s and 1960s without the high-powered computer programs engineers have today.

Owning Hardware

As a lead design engineer, Shawn “owns” the design of the rotating hardware on the CFM56 engine, the most popular aircraft engine in the world with more than 15,000 engines sold globally. Every 3 seconds, every single day, an aircraft takes off with a CFM56 engine on it. He’s responsible for every aspect from manufacturing issues, to process improvement, finding way to reduce production costs, enhance performance, and repairs. He can draw upon the support of a team of materials and field service engineers, among others, but it’s his responsibility. 

Lives, Certification, and Redesign

GE collects data from the airlines to determine how they fly their airplanes. Shawn uses analytical tools to determine how much stress each part of his engine undergoes. He then uses engineering principles to determine how much low cycle fatigue (LCF) damage occurs due to the stress the part experiences. This damage is then translated into a life for the part in the unit of cycles. A cycle is defined as one takeoff and landing or one flight. The part is then certified to fly for a certain number of cycles before it must be removed from an engine.

Low cycle fatigue is similar to breaking a paper clip. If you unfold and fold a paper clip one time, you impart a certain amount of damage to the clip. That would be the equivalent of one cycle. If you repeatedly unfold and fold the paper clip, eventually the clip breaks after a certain number of folds due to the accumulation of damage that occurred due to the repeated unfolding and folding of the paper clip. Shawn’s job is to predict how long it would take to “crack” the hardware.

Shawn is always looking for ways to extend the life of his engine, make repairs easier and less costly, and improve performance. Recently, his work to improve the performance of the engine included an upgrade program for all of the rotating parts in the entire core of the engine. Shawn led the certification program to redesign all the hardware.

The Challenge of New Analytical Tools

The CFM56 was originally designed in the early 80’s. Both technology and analytical tools have improved since then. Shawn’s challenge was to upgrade the engine using the updated analytical tools while still meeting the ultimate life requirement for all rotating hardware with minimal additional weight and cost.

Keep Your Wings On

The changes Shawn and his team made to the engine not only recertified it to meet the ultimate life expectancy, but also allowed the airlines to no longer have to take the engine off wing to replace parts until the ultimate life expectancy—a great money and time savings.

If you pull an engine off to replace a life limiting part of 12,000 cycles, without changing other parts rated for 20,000 cycles, for example, you will have to pull the engine off wing again at an additional 8,000 cycles. With the new process all parts are brought up to the new ultimate life when an engine is pulled off wing—generating substantial savings in time and cost over the life of the engine. Since most engines are under service contract to GE, the new approach generates cost savings for GE as well as the airline customer. For passengers, this new approach also increases reliability of the engine.

The Sky's the Limit

For Shawn his career as an aerospace engineer has been most rewarding. The challenge and complexity of his product along with mentoring responsibilities, educational program, and the ability to balance his career with family life have been very satisfying. “There is no better feeling than achieving life goals while having fun doing it. My engineering career has allowed me to have many great experiences and I can’t wait to see what lies ahead for me in the future.”

Click here for the Extreme Engineer profile of Heather Paul.