Mohammad Ehteshami has helped build the world’s largest and most powerful jet engines during his 31-year career at GE. But as a boy in a tiny desert village in Iran, odds were he would grow up farming pistachios. That is, until his mother intervened. I caught up with Ehteshami at the Paris Air Show, to talk about the latest jet engine technology.
Tomas Kellner: How did you end up running jet engine engineering at GE, arguably the world’s largest jet engine maker?
Mohammad Ehteshami: I grew up in a very small desert village in southeastern Iran. Even now it has only 98 people and 27 families. My mother was the only woman there who could read and write. She told me early on that by no means I would be farming pistachios like everyone else. She said: You go make planes.
TK: How did you respond to it?
ME: Well, you cannot argue with your mother. I started learning English, went to the U.S. consulate in the city of Shiraz and applied for a student visa. Back then we still had one. The visa came through and I went on to study mechanical engineering at University of Massachusetts, Boston in 1978.
TK: It was your mother’s dream coming true.
ME: Well, not so fast. You have to understand that I had no money and Boston even then was very expensive. I had to find jobs to support myself. I was driving a taxi, and working in construction. But it was still hard to make ends meet. So I left the university and enrolled at Old Dominion University in Norfolk, Va., which had a good engineering program and it was affordable. I liked engineering so much that after I got my degree, I went to the University of Cincinnati in Ohio to get my masters degree.
TK: Cincinnati is the home of GE Aviation. So now your mom’s dream was surely fulfilled.
ME: Not even. I actually held three jobs before I joined GE. That’s because I wasn’t looking for a job. I was looking for satisfaction. A few weeks after I joined GE, I told my wife that I found my place and that I’d either retire, get fired or die in this job, but I wasn’t quitting. Today I still tell her that I haven’t worked one day in my life. I’ve been having too much fun.
TK: What engines have you helped design?
ME: I’ve worked on big engines as well as small ones, like the one for the HondaJet. But nothing compares to the GE90 for Boeing’s 777 plane, which turned out to be the largest and most powerful jet engine in history. It was also the most demanding. This project made me a better man.
TK: How so?
ME: We were competing with Rolls Royce and Pratt & Whitney for the contract and at the same time introducing technologies that have never been tried in jet engines before, like fan blades made from carbon fiber composites. We also wanted to build an engine with architecture that could grow with the plane – which turned out to be a smart choice since our engines still power them.
We started in 1989 and were on a very tight deadline and there were many humbling moments. When you think that a test is going to go one way but the engine performed differently, I would feel it both technically and emotionally. I had to report the results the next day.
TK: Tell me about those tests.
ME: Take the composite blade. There are 22 of them in the large fan of the engine. Normally, they are made from metal, but composites, which are made from layers of carbon fiber and resin, are lighter. They allowed us to make the world’s largest jet engine fan, 128 inches in diameter. But these blades, for example, also have to take a large bird inside the engine and keep it operating safely. When we introduced the blade, people thought we were crazy. In their minds the technology wasn’t ready. But we pushed on, lost many nights of sleep, and got it done. The engine was certified in 1995 and today the GE90 engine is the only engine that powers new 777 planes.
TK: The GE90 was designed 20 years ago. What has happened to the technology since?
ME: We keep perfecting it. Where the GE90 has 22 blades, the GEnx, which we built for Dreamliner, has 18, and our latest engine in development, the GE9X, will have 16 blades, even though it will have the world’s largest fan with 11 feet in diameter. From bottom to top, that’s higher than a basketball hoop.
TK: What plane will the GE9X go on?
ME: That engine will power Boeing’s next-generation 777X plane, the successor to the 777. But this time we are the sole engine supplier for the plane. This engine will be the most advanced engine in our portfolio. It will have parts made from ceramic matrix composites, 3D-printed components, and, of course, carbon fiber composite fan blades. No other manufacturer has carbon fiber composites blades in service and we are already on the fourth generation.
TK: A few years ago 3D printing was a futuristic technology and now it’s already inside flying engines. What will future engines look like?
ME: If you look out to 2025, it could be anything: from engines with open rotors to parts and materials that are hidden – like coatings – that will make engines more efficient. We will be building more efficient and more durable engines that will allow airlines to keep them on wing and keep flying.
TK: What about speed?
ME: Speed is a factor, but it has to make business sense. After all, we already had a supersonic plane, but it was expensive to operate.
TK: You are now effectively running all engineering at GE Aviation. Your mother must be proud.
ME: Well, I did bring her to Cincinnati and showed her the engines I worked on. But she said that they looked too heavy and that they weren’t a plane. In her mind, I am still not building planes.