Born: United States of America
Primarily active in: United States of America

From Vertiflite Leadership Profile: May/June 2020

Dr. Oliver Wong, Associate Director for Design, Simulation and Experimentation, CCDC Aviation and Missile Center, Technology Development Directorate — Aviation

At NASA Ames Research Center in Mountain View, California, Oliver Wong leads US Army researchers skilled in aeromechanics, flight controls and conceptual design. His Technology Development Directorate–Aviation/Design, Simulation and Experimentation (TDD-A/DSE) laboratory — what was once called the Aeroflightdynamics Directorate (AFDD) — is part of the Combat Capabilities Development Command (CCDC) Aviation and Missile Center (AvMC).

Wong explained, “We produce physics-based engineering tools to help with the successful development of new-build rotorcraft and major modifications. We advise the greater Army on design criteria, and the impact of requirements on the resulting air vehicle.” DSE experts now consider innovative Future Vertical Lift (FVL) concepts. Wong added, “We conduct basic research to improve modeling and simulation tools and knowledge to understand the underlying physics of rotorcraft. That’s so we can identify technologies that address performance barriers.”

Wong acknowledged, “We have made significant progress on conventional rotorcraft configurations. We have enough experience to know where the biggest problems are. But now we’re going to have advanced configurations, like FARA [Future Attack Reconnaissance Aircraft] and FLRAA [Future Long Range Assault Aircraft], that are not going to look like a conventional helicopter, and are likely to have new challenges or amplify some of the previous challenges.”

The FVL Joint Multi-Role Technology Demonstration (JMR-TD) science and technology effort has been evaluating advanced tiltrotor and compound helicopter configurations relevant to FVL. Wong noted, “One of our research areas is multiple independent flight effectors. These new configurations have multiple control surfaces that can control the pitch of the aircraft, for example. Which effectors do you use in which phase of flight? How do you allocate those if one is damaged in battle? Can you switch over to the other effector so that you can continue the mission?” He added, “As we move into the future with all these new configurations, we don’t have enough experience to know where the blind spots are. There is going to be a lot of carefully thought-out research to develop and validate our tools.”

The TDD-A/DSE has a mix of civil servants, contractors, visiting scholars and interns doing fundamental and applied research. Wong said, “We mature selected technologies to warfighter capabilities, but we don’t do that in a vacuum. We work with other Army organizations, other services, other agencies and industry.” Last year, Army TDD-A/DSE researchers teamed with others when the Marine Corps CH-53K suffered exhaust gas re-ingestion. “The Computational Aeromechanics Tech Area out here was part of that team, and they did the majority of the high-performance computing analysis that helped the Navy resolve that problem.”

Branching Out
Oliver Wong grew up in Livermore, California, east of San Francisco. He noted, “Livermore has two national laboratories, Lawrence Livermore National Lab and the California campus of Sandia National Labs. They had a large influence in my interest in math and science. Most of my peers had parents working there.” Wong’s own father, Winston, was a PhD mechanical engineer researching new metallurgical formulas at Kaiser Aluminum. “I recall going into his lab on Saturdays. That was a very influential piece of my upbringing.”

The future rotorcraft researcher had no early interest in aviation. He recalled, “Growing up, most of my exposure was mechanical engineering and other sciences, but nothing aerospace-related. It wasn’t until I went to grad school that I was introduced to that.” The University of California at San Diego nevertheless offered an attractive foundation. “They had a good mechanical engineering program. The in-state tuition helped as well, and it’s a beautiful place to go to school, on the bluffs overlooking the Pacific Ocean.” Wong earned his bachelor’s degree in mechanical engineering in 1996. “I didn’t know exactly what I wanted to do, but mechanical engineering is a very broad field that allows you to branch out in different directions.”

One UCSD research opportunity gave Wong pivotal direction. “I volunteered in a lab during my junior and senior years, doing a special topics study class. I was taking measurements of turbulent mixing using several laser-based diagnostic techniques. That was something that was interesting to me, non-intrusive measurement techniques and the science of those measurements.”

Georgia Institute of Technology provided graduate research opportunities and an introduction to rotorcraft. Wong explained, “I was accepted to Georgia Tech, which was one of the Vertical Lift Centers of Excellence, into their experimental aerodynamics group which does a lot of non-intrusive measurements.” Wong’s dissertation characterized tip vortices properties of a rotor in forward flight using laser Doppler velocimetry. “That’s where the hook for my aerospace interest came in.”

At Georgia Tech, graduate advisor Prof. Narayanan Komerath suggested a research opportunity back in California. Wong said, “My first quarter there, I was part of a team that came out to NASA Ames to work with Dr. Frank Caradonna in the 7- by 10-ft [2.1- by 3.0-m] wind tunnel. We tested a rotor in axial flight, examining rotor performance as a function of climb rate. It was a weird circle-of-life thing that gave me my first exposure to Ames. Twenty-four years later, I’m leading the organization that Frank was part of.”

Georgia Tech awarded Oliver Wong his master’s degree and doctorate in aerospace engineering. “I went directly out of grad school to AMRDEC [Aviation and Missile Research, Development and Engineering Center, equivalent to today’s AvMC] at the NASA Langley, Virginia location.” Dr. Wong joined a group of about 10 AMRDEC employees at Langley in 2002. “I started in the 14- by 22-ft [4.3- by 6.7-m] subsonic wind tunnel. We were just getting ready to go in with a Comanche model.” In flight test, the RAH-66 Comanche scout-attack helicopter encountered tail buffet from turbulent flow off the main rotor pylon. Wong recalled, “This was a test to examine rotor performance and alternate tail configurations. That was my first project when I got there.”

Wong served 11 years as a Langley researcher. “We worked on a series of unmanned air vehicles, looking at the aeromechanics and aerodynamics of UAV [unmanned aerial vehicle] shapes. We also looked at a Joint Heavy Lift design. The last thing that we were working on when I was a researcher was wind tunnel testing of the OH-58F.” The cockpit and sensor upgrade for the Kiowa Warrior changed the helicopter aerodynamics when new sensors replaced the familiar mast-mounted sight. “I also led a team that used pressure-sensitive paint on rotor blades — we won the American Helicopter Society [now VFS] Gessow award for that in 2012,” given for the best technical paper presented at Forum 68 (see

The AMRDEC management track made Wong the lead for the Experimental Mechanics Technical Area in 2013. “I was at Langley, but the group was split across the two locations — half were at Langley and half were at Ames.”

Tools and Tests
When West Coast retirements opened the director’s position at Ames, Wong returned to California with a temporary posting as the Deputy Director in January 2018. He assumed his permanent assignment as Associate Director (the lead position at the Ames site) last year. TDD-A/DSE now has about 70 civil servants and 36 contractors. “We’re actively building a larger team,” said Wong. “Broadly speaking, they fall into aeromechanics — both experimental and computational — flight controls and conceptual design. Within those areas, it’s a mix of aerospace, mechanical engineering, computer science and wind tunnel technicians. We also hire outside those areas if the person brings the skills we need.”

The Army started its rotorcraft research partnership with NASA in 1965 and continues to team with the civil aerospace agency. Though Army researchers have done little with electric vertical takeoff and landing (eVTOL) concepts, Wong noted, “NASA is doing a fair amount of that. We have built a close relationship through the NASA/Army partnership. It provides critical mass in the vertical flight area, so that as a rotorcraft community, we have the waterfront covered. That’s one of the reasons we’re co-located at NASA centers. Both sides are able to leverage information and expertise when needed.”

Army Ames researchers routinely develop analytical tools, control laws and new designs. “The subject matter expertise for all these areas resides in the workforce out here.” Wong noted, “Tools have gone through a revolution with coupled computational fluid dynamics and computational structural dynamics since 2004. We’ve made tremendous strides in coupling the structural response to the aerodynamic forcing function. That has improved our accuracy tremendously. That technology wasn’t accurate enough when we were going through Comanche.” According to Wong, “A lot of this is developing very high-fidelity tools to help us correct aeromechanical problems. No rotorcraft has ever made it through flight testing without some aeromechanics problems. The tools we develop enable us to study them and suggest fixes.”

Experimental techniques have also improved. Wong offered, “In general, all the standard techniques — particle image velocimetry, laser Doppler velocimetry, photogrammetry — those have all gotten better because of technological advancements. Now that our modeling and simulation are more accurate, we need to measure things that we never had to measure in the past. For example, we developed an infrared thermography technique to measure boundary layer transition on rotorcraft. That’s been done in the fixed-wing world where it’s comparatively easy because you don’t have the motion of rotor blades.” Wong added, “There have been evolutionary improvements, and there have been other areas where we’ve had to apply and develop totally new techniques to measure quantities that we didn’t need before. The JMR-TD has been very good for us from a validation standpoint, enabling us to validate our tools against realistic configurations.”

The flight controls group at Ames also conducts applied research on aircraft handling qualities and has been developing draft design standards for Army airworthiness authorities. Recent work has expanded these design standards for the new high-speed regime of FVL aircraft. New Mission Task Elements are proposed for high-speed flight.

Unique TDD-A/DSE flight test rotorcraft previously stationed at Ames — the fly-by-wire JUH-60A Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) and EH-60L Black Hawk 657 now with Degraded Visual Environment Mitigation (DVE-M) technologies — have relocated, but as Wong explained, “Those assets are now at Joint Base Langley-Eustis, but they’re part of the rotorcraft in-flight laboratories branch organizationally under me.”

The flight test assets at Langley-Eustis also include Yamaha RMAX unmanned aircraft system (UAS) helicopters for autonomy research. “I certainly believe autonomy is going to be important in the future,” acknowledged Wong. “There is a stated desire for a paradigm shift, moving from pilot to mission commander. Rather than having someone focused on flying the aircraft, we’d have someone focused on completing the mission while the aircraft flies itself. The buzz-word is ‘cognitive off-loading.’ Autonomy is a required technology to enable cognitive off-loading and successfully shift the paradigm.” Own-ship autonomy is studied by Ames researchers. Managing multiple UAS is the work of the TDD-A Systems Integration and Demonstration Area at Langley-Eustis in Virginia.

Oliver Wong joined VFS in 1996. “I was on the Test and Evaluation Committee for 10 years and served as the technical director for the Hampton Roads Chapter for 11 years. One of the greatest benefits of membership is the networking. That’s something the younger members don’t necessarily see because of recent restrictions on conference travel. They’re missing out on opportunities that I had early in my career. The ability to network and learn from others in the field is invaluable. In TDD-A/DSE, we maximize participation in VFS at the local, regional and national levels to the greatest extent possible. The networking helps you over the course of your career.”