“I ended up staying in the group for 15 years,” said Multhopp. “I think, like a lot of people, my first job was my best job. That was the group that produced DATCOM, which is a collection of aerodynamic methods that is used throughout the aerospace industry. We did stability and control on nearly every project that the Air force was interested in.”
From there, Multhopp went to the FDL’s Aeroconfiguration Branch, where he worked as the branch chief and later, as the branch technical advisor. Here, he contributed expertise in a broad range of research topics, including aircraft energy efficiency, hypersonics, launch concepts, and fighter aircraft.
Although the branch has been reorganized and renamed several times since, it is where he remained until retirement.
What prompted him to stay with one organization for his entire career? Multhopp simply said, “I liked the work. It matched up with my field of study, and I liked the people.”
Within the Aerospace Systems Directorate, it is hard to find someone who doesn’t know Multhopp, or who hasn’t worked with him in some fashion.
Multhopp recalls that the first program he worked on was the X-29 forward swept wing concept vehicle, which advanced to wind tunnel testing. Since then, he says he has played some type of role in more than half the X-series planes developed within and in conjunction with in the Air Force, culminating with the recent X-61 Gremlins project.
For Multhopp, it is difficult to pick one project that stood out as a favorite over his career.
“I liked working on the National Aerospace Plane,” he said, explaining that although the program, also known as the X-30, was ultimately canceled, it was a project that produced a lot of useful design work and research that benefited future projects. Other favorite projects included various airship programs including Walrus and Blue Devil, as well as Vulture, a solar-powered high-altitude, long-endurance aircraft.
Multhopp’s enthusiasm for aircraft research and design is not surprising considering his family legacy in aerospace. His father, Hans Multhopp Sr., was a renowned aeronautical engineer who developed groundbreaking concepts that continue to influence modern aircraft design.
Already a highly respected designer in his native Germany for his work on lifting body surfaces and single engine swept-wing aircraft, the elder Multhopp worked for a short time in Great Britain before moving with his family to the United States in 1949 to work for the Glenn L. Martin Co. in Baltimore. He continued his aircraft design work but also began to work on space programs and eventually was named chief scientist.
It was through his work at Glenn L. Martin that Multhopp Sr. became involved with the Flight Dynamics Laboratory, which was interested in lifting body designs. Through a contract with the laboratory to develop a full-scale model of the lifting body aircraft, he put his design to work. This effort ultimately resulted in the X-24, a predecessor of the space shuttle.
Eventually, Multhopp Sr. moved on to work for General Electric Aviation, which landed the family in the Cincinnati area and, over time, influenced his son Dieter’s decision to continue the family legacy in aerospace research at Wright-Patterson Air Force Base.
Although the elder Multhopp passed away in 1972, he left a rich heritage for his son to build upon.
“I inherited a basement full of his papers, and I learned a lot from reading them as I was an undergraduate at University of Cincinnati,” Multhopp said. “Early in my career here, I started meeting guys who had worked with my father.”
Reflecting upon the family’s work in aerospace, Multhopp said, “My father really started in the industry post-grad as a working researcher in 1934. I’ve worked here since 1979, so that covers 85 years. That’s most of aviation history.”
Throughout his career, Multhopp has worked on a number of projects that have made big impacts in the aircraft industry, including the aforementioned X-29, the X-31 high angle of attack fighter, early Joint Strike Fighter concept vehicles, and the Hypersonic Technology Vehicle 2, a reusable prompt global strike concept vehicle. He helped investigate an anomaly on the HTV-2, which merited him the Perkins Award for engineering excellence, one of the Aerospace Systems Directorate’s highest awards.
“I’ve had a lot of fun, and I think I’ve made some contributions while I was here for 40 years,” he said.
As he looks back on his own distinguished career, Multhopp said it’s working with the people that stands out most in his mind. “What I was most proud of was that when I was a group leader, a first-level supervisor, I helped make sure six of my employees finished up their Ph.D. programs.”
He added that many of the people who worked under him went on to have accomplished careers of their own.
And to Multhopp, at the twilight of a career full of challenges and fulfillment, that is what it is all about: building a bright future in aerospace research.