Jillian Wright

Mar 14th 2020

Aircraft Design in the Age of Autonomous Systems: Test Pilots Still Play Essential Role


Unmanned aircraft systems, or drones, have become a ubiquitous part of our lives. Smart, microprocessor- and software-driven flying machines now regularly perform military missions tagged as “dull, dirty or dangerous,” while local government agencies and private entrepreneurs enlist drones for missions such as aerial surveillance of fires, wedding photography and small-package deliveries.

Against this backdrop, however, human test pilots — those daring young men and women in their flying machines of movie legend — remain a central and indispensable part of aircraft design, and the teams and processes that develop, test and field new aircraft systems, both manned and unmanned.

“Developmental test pilots serve as the ‘bridge’ between engineers (who design the plane) and operational pilots (who fly the plane),” explains Bob Hood, a retired U.S. Air Force test pilot and one of 15 active test pilots employed today by Northrop Grumman. “The test pilot must be able to speak ‘engineering’ to help aircraft developers produce a plane with good flying qualities that can meet its mission requirements. He must also help developers produce a flying experience for pilots that is engaging, intuitive and easy to understand.”

Start With STEM

Many test pilots begin their careers as military pilots with a degree in engineering or another technical degree such as physics or mathematics. “To enter test pilot school, you also have to have substantial flying experience — a minimum of 750 flight hours — in military aircraft,” explains Troy Johnson, a retired Air Force test pilot and Northrop Grumman Aerospace Systems’ chief test pilot. The U.S. Navy and the Air Force both operate their own test pilot schools; commercial test pilot schools are also available in the U.S. and abroad.

Join the Dream Team

Ironically, explains Don Weiss, a retired U.S. Marine Corps test pilot and Northrop Grumman’s chief B-2 stealth bomber test pilot, “a majority of the contributions of a test pilot are not made while seated in an aircraft.” The role of a test pilot actually begins, he explains, “in the ‘dreaming’ stage of aircraft design as part of a team considering all aspects of aircraft operation and performance.”

The test pilot contributes to everything from aircraft design criteria; vendor selection for specific subsystems; and the layout of cockpit controls and displays; to helping develop simulators, flight test plans and training programs — and the earlier in the program, the better.

“The single most important job of a test pilot,” advises Wayne Staley, a retired Northrop Grumman test pilot who began his test pilot career in the Air Force, “is to collect the data that the aircraft’s designers need to evaluate the operation and performance of the aircraft.”

Bring the Right Stuff

The most important characteristic of a test pilot? “Integrity,” says Weiss. “Both engineers and pilots have to trust, intimately, the real-time findings of the test pilot. If there is an issue with the plane, the test pilot has to be very transparent so that the situation is well understood by designers and operators alike.”

Good test pilots need to be disciplined, curious, and cool under fire. According to Hood, however, “fear is not part of a test pilot’s vocabulary.” If something unusual happens during a flight, he says, “You have to operate in the present. It doesn’t matter how you got there, only how you’re going to fix it.”

And this advice has paid off. In October, both Hood and Staley were recognized by the Society of Experimental Test Pilots (SETP) for their career-long ability to meet challenging flight test requirements. Both men were honored as members of SETP’s 2017 Class of Fellows at the organization’s annual meeting, in Anaheim, Calif.

Evolve With Technology

As aircraft design technology has evolved, so too has the role of the test pilot. “In the 1950s, pilots took planes out to see what they would do. Today we take aircraft out to verify the predictions of our models,” says Staley. In an age of sophisticated wind tunnel testing, modeling and simulation tools, he adds, “we don’t get into the cockpit until our predicted performance is good.”

But a new aircraft system doesn’t need a cockpit to benefit from the skills of a test pilot.

“Increasingly, high speed computers do most of the ‘thinking’ and management of flight control surfaces for autonomous systems,” says Weiss. “But you still need someone who can evaluate the air vehicle’s flying qualities, because humans are involved in operating it from the ground.”

FAA rules require operators of certain classes of unmanned systems to be flight qualified as pilots, and instrument rated. Test pilots work closely with designers of ground control stations, therefore, to ensure that aircraft controls, displays, and methods of presenting information are consistent with how our pilots are trained. Test pilots also help autonomous system designers ensure that an aircraft’s avionics and flight control systems can respond appropriately to human air traffic control commands to the air vehicle operator.

“The goal is to design autonomous systems so that they are fail-safe and foolproof, but every once in a while, these systems fail and you end up losing an aircraft,” observes Johnson. “By including test pilots’ expertise in the development of an aircraft, there’s a much better chance that a pilot can bring it home safely.”

Manage the Risks

In the end, being a test pilot centers on risk management, whether you’re testing a manned or an autonomous system.

“The test pilot and the test team spend a lot of time discussing and mitigating risks before a plane ever takes off,” explains Staley. “These discussions involve the people who understand best how the aircraft works. Our shared goal is to identify possible problems and minimize our exposure to those problems. That way we’ll always have a safe escape route if unexpected situations arise.”

Enjoy the Ride

For all the discipline, teamwork, and mission planning, however, test pilots still go to work to do what they love most — fly high performance aircraft.

“One of my most memorable experience was testing the weapons delivery capabilities of a military jet over the ocean,” recalls Weiss. “On test day, there was a marine layer of clouds. We needed to have clear conditions to complete the test properly. We spotted a hole in the clouds that was just large enough to drop in, release the weapons, document it and get out. That was fun, and it felt good to accomplish the test under challenging conditions. Most importantly, we got the data. I call that a pretty good day at the office.”