Panelists: Moderator Starr Ginn, deputy aeronautics research director, NASA’s Armstrong Flight Research Center; Edward L. Burnett, senior fellow, Modeling, Simulation, and Controls, Lockheed Martin; Robert E. Curry, chief scientist, Armstrong; Bill Gray, chief pilot, U.S. Air Force Test Pilot School; Nils Larson, chief, Flight Crew Branch, Armstrong; Daniel Murri, NASA technical fellow for flight mechanics, NASA’s Langley Research Center; Dana Purifoy, director of flight operations, Armstrong; Art Tomassetti, director and F-35B U.S. Marine Corps program manager, Lockheed Martin
by Tom Risen, Aerospace America staff reporter (2017-2018)
Some aircraft engineering obstacles remain impossible to discover without building an experimental X-plane and sending a pilot to fly it, despite advances in ground testing and remote-controlled flight, a group of scientists and test pilots told the 2017 AIAA AVIATION Forumin Denver.
Flight simulators and wind tunnels have long been used to test an aircraft’s design before the final product is built, but they cannot always re-create the way planes will fly in real life, representatives from NASA, the U.S. Air Force and Lockheed Martin explained June 5 during the “X-Planes: Discovery Through Flight” forum.
The X-35, which the Defense Department tested in a joint operation as a prelude to the F-35, taught the military how to improve the jet’s hovering thrusters, said Art “Turbo” Tomassetti, who flew both planes for the Marine Corps. Tomassetti retired from the Marines in 2013 and is now the F-35B Marine Corps program manager at Lockheed Martin.
Tracking how more than 18,000 kilograms of thrust from lift fan of the X-35 caused it to stall in real life was “extremely difficult if not impossible to model” without a test plane, Tomassetti said. Pilot feedback about flight experiences like landings and cockpit controls is also important for design improvements, he added.
Bill Gray, chief test pilot at the U.S. Air Force Test Pilot School, said test pilots will always be necessary, but “autonomy is kind of where we are headed,” despite some fears from the aviation community that remote piloting will replace humans.
However, unmanned X-planes are often not less expensive or more efficient than sending a test pilot, said Dana Purifoy, director of flight operations for NASA’s Armstrong Flight Research Center.
“You have to be careful in deciding what you want to obtain and whether it is worth it to use [unmanned planes],” Purifoy said.
Situations where unmanned X-planes could be useful include long-endurance tests and high-risk flights of unproven aircraft, said Nils Larson, the chief test pilot at Armstrong.
NASA is approaching the preliminary design review process as a prelude to building an X-plane to test low-boom supersonic flight, a NASA spokesman said. There is no timeline for the design review, but NASA expects the process to be complete by the end of June.