Born: United States of America
Primarily active in: United States of America
From Leadership Profile: Vertiflite September/October 2016
Carl G. Schaefer, Jr., LightningStrike VTOL X-Plane Program Manager, Aurora Flight Sciences Corporation
Under a Defense Advanced Research Projects Agency (DARPA) contract, Carl Schaefer leads the Aurora Flight Sciences team building an X-Plane that will take off and land vertically, hover with 75% greater efficiency than today’s VTOL platforms and cruise at a speed of 300-400 kt (555-740 km/h). Schaefer observed that, “An X-Plane program comes along very few times in one’s career, so we’ve had no problem attracting really good talent on the program.” His mixed engineering team will grow from about 45 people today to 80-85 as the innovative unmanned demonstrator with its distributed electric propulsion system advances to the flight-test phase in 2018. “That’s the beauty of working at Aurora,” noted Schaefer. “You can take something here from conceptual design through detail design, manufacturing, flight test, and delivery to the customer. We really do it all.”
Despite working on a range of interesting assignments throughout his career, including the U.S. Navy’s F/A-18 Hornet strike fighter and other fixed-wing programs, rotary-wing flight remains Schaefer’s focus. “I find it much more challenging,” he explained. “You have a lot of moving parts! The unsteady aero is particularly difficult to work with, to identify, to understand. The identification of flight and ground loads is more difficult. The assessment of fatigue lives of components is more difficult. When you look at the environments that helicopters work in, whether it’s the marine environment, brownout conditions in a desert environment, or the dynamic interface issues in landing and taking off from the back of a ship, I think there are so many interesting challenges in rotary-wing aviation you don’t see with fixed-wing aircraft.”
When asked how he sees the industry evolving in coming years, Schaefer replied that he is fascinated by the possibilities of personal transport. “In the next 20 to 30 years, I firmly believe a personal VTOL transport is very likely,” he said. “I’m not sure what that will look like — an open rotor system, a ducted fan, a jet-borne powered lift aircraft … who knows?” He added, “I think LightningStrike is probably two decades ahead of its time.”
Engineering for Flight
Born in Atlantic City, New Jersey, Carl Schaefer grew up in a family without engineers and attended high school in Marion, Virginia. “I was the very first of my family, on both sides, to get a college degree,” he noted. “Having said that, my father, who was enlisted-Navy during the Vietnam War, always had a fascination with aviation and is to this day an avid, expert model aircraft builder. I probably get it from him.”
With his parents favoring an in-state college, the junior Schaefer applied successfully to Virginia Polytechnic Institute and State University (Virginia Tech) with an eye to electrical engineering. He recalled, “When I got to Tech in my freshman year, they had an open house in the Aerospace and Ocean Engineering Department. As soon as I saw what they did over there, I switched my major.” The university offered a bachelor’s degree in Aerospace and Ocean Engineering. “You had a choice to go down one path or the other. I elected to stick with aerospace.”
Even with no helicopter content in the aerospace curriculum, Virginia Tech gave Carl Schaefer vertical flight inspiration. During Schaefer’s junior year, an upperclassman founded a student chapter of AHS. “I went to the AHS student chapter meeting just to see what it was about, and that was what really turned my interest to helicopters,” he said. “I’ve always been fascinated with helicopters, both professionally and personally — I fly RC helicopters in my spare time. It all really goes back to that student chapter meeting that year.”
Virginia Tech also put Schaefer in a co-op program at the US Navy’s David Taylor Research Center — now the Carderock Division of the Naval Surface Warfare Center. “I worked in a group that did submarine hydroacoustics,” he said. “I did that for about three years with most of the work involving wind tunnel and water tunnel testing. I was offered a job to go back after graduation, but I just had an interest in aviation. I wanted to get back to airplanes and helicopters. So after I left school, I took a job at the Naval Air Test Center [at Patuxent River, Maryland] as a flight test engineer. I worked in the Rotary Wing Aircraft Test Directorate and focused most of my time on Marine Corps helicopters.” Assignments included identifying loads for the GAU-2B/A minigun on the UH-1N Huey.
The Naval Air Systems Command (NAVAIR) structures branch, then in Arlington, Virginia, provided Schaefer with new challenges. “We did a lot of work in helicopter air combat, trying to characterize the impact of air combat on helicopter dynamic component fatigue lives,” he said. “I really enjoyed trying to understand the whole helicopter air combat environment — the pilots that flew them and the engineering challenges associated with the whole fatigue-life assessment in that environment. We also did some neat work adapting neural networks for dynamic component loads prediction and helicopter low-airspeed prediction.”
NAVAIR also exposed Schaefer to fixed-wing investigations: “I worked on the F/A-18 program as a structures engineer for several years. It was interesting working on the fast-movers after having worked on helicopters up ‘til then.” While at NAVAIR, Schaefer earned the respected Senator John W. Warner Fellowship for Systems Engineering and a master’s degree in Systems Engineering from Virginia Tech. He also did work for NAVAIR on the Joint Advanced Health and Usage Monitoring System (JAHUMS).
NAVAIR’s relocation to the Patuxent River provided the impetus for Schaefer to leave government and — together with his brother — launch an engineering consultancy in 1995. “We learned a whole lot about business,” he said. “We were looking at the impact of HUMS [Health and Usage Monitoring Systems] on component replacement times and what they did for aircraft availability — whether we could count on HUMS reducing logistics costs and whether we could work on improving demand for spares worldwide.”
Joining Aurora Flight Sciences in 2003, Carl Schaefer was hired to work on the DARPA Clandestine UAV program that morphed into the OAV-II: the US Army company-sized Organic Air Vehicle for the Army’s Future Combat Systems (FCS). Since then, his company resume has grown to include work on the unmanned GoldenEye ducted-fan technology demonstrators built for DARPA, as well as the big CH-53K main rotor pylon and engine nacelles in production for the Marine Corps.
The cancelled OAV-II gave Aurora a useful foundation in ducted-fan technology applicable to the VTOL X-Plane. “We certainly refined a lot of the analytical tools,” observed Schaefer. “We have a better understanding of the relative contribution of the duct and the fan, as well as the associated acoustics environment. Certainly with LightningStrike, one of the big lessons learned from OAV-II and our GoldenEye-50 was, ‘You can’t design the fan or the duct without considering the other. You have to look at the whole package.’” With wing and canard, the LightningStrike VTOL X-Plane has no fewer than 24 ducted fans working in concert. “They have a really big impact on external aero,” explained Schaefer. “Understanding that is crucial.”
The VTOL X-Plane team at Aurora headquarters in Manassas, Virginia works with a computational aerodynamics contingent in Cambridge, Massachusetts. “It’s a truly multi-disciplinary team,” said Schaefer. “Right now, probably about a fourth of the program personnel are designers and structures analysts as we flesh out the airframe and the structure, but certainly we have a lot of electrical engineers, software engineers and flight control engineers. Our aero group is also very strong; it needs to be to support the heavy Computational Fluid Dynamics [CFD] workload. In fact, we’re not going back to the wind tunnel in this phase [detail design] because all the aero work is being done with CFD.”
In parallel with its new X-Plane, Aurora is building the physics-based models that explain how the LightningStrike will transition from hovering to forward flight and back again. “We like doing CFD, but it’s not a panacea,” said Schaefer. “We tend to lose sight of engineering first principles that provide the intuitive insight into what’s really happening.” He added, “I actually think unsteady aero is not well understood. The state of the art of those tools — the Computational Fluid Dynamics, things like that — are much, much further along than they were just 10 years ago, but unsteady aero is really difficult.”
Industry and Community
The American Helicopter Society (now AHS International) that first inspired Carl Schaefer to pursue a career in rotary-wing flight remains a source of inspiration and a tool for the rotorcraft professional. “AHS is a wonderful organization,” he said. “One of the nice things is that it’s a very small, tight community, and all of us have known each other for many, many years — going on 30 years for me. It’s a unique community. The value I get out of that are the professional contacts, the technical conferences. AHS is the premier professional organization for anyone in the VTOL industry, and it brings it all together for us.”
Another place where Schaefer finds himself surrounded by an extremely talented cohort is Aurora. Even within the company, the LightningStrike program manager competes for engineering talent. “We all want the same stars, and we negotiate with each other,” he said. “I have a lot of people who worked on OAV-II and the CH-53K program that I managed here several years ago…. I’m convinced we have some of the best engineers in the world here.”