However, a more radical concept for testing a wider range of advanced technologies is also being considered, says James Kenyon, associate director of aerospace technology in the Office of the Secretary of Defense. “We are raising the possibility of a larger modular X-plane, inspired by the X-56 idea, which could work.” Nevertheless, several fundamental questions still need to be answered, he cautions. “Is it feasible, will it be cost-effective, how useful will it be—all these are to be determined,” he says.
The X-56A, initially known as the MUTT (Multi-Use Technology Testbed), is being developed by Lockheed Martin for AFRL, which intends to employ it to evaluate technologies for mitigating aerodynamic wing flutter. Supported by NASA, which plans to use the testbed as a long-term research asset after the AFRL work is complete, the X-56A will deliberately explore dangerous parts of the envelope. As this could lead to the destruction of a wing, the X-56A is provided with a ballistic parachute recovery system. It is also uniquely designed with substitute multiple fuselages and wings to enable a rapid return to test.
The X-56A continues the recent trend to smaller, more affordable unmanned X-planes, while the AFRL vision calls for a larger, multirole testbed of the type originally envisioned to evaluate advanced concepts in NASA's Environmentally Responsible Aviation (ERA) program. There were efforts to share the cost of this testbed with other agencies, but the plan was scrapped because of budget restrictions. “We asked for an experimental flight vehicle for ERA, but the Office of Management and Budget (OMB) asked for a 50% cut in our requested funding. Now we have to show the ERA goals without the benefit of an experimental vehicle,” says NASA Aeronautics Research Mission Directorate Deputy Associate Administrator Thomas Irvine.
Because of worries over the way budget cuts were damaging flight-test capabilities, NASA approached the NRC. “We were concerned. Is that skill atrophying to the point where it won't be useful going forward? So we reached out to the [National Academy of Sciences] to help us try to figure out how to reach a healthy level,” he says.
The NRC report, which was briefed to Congress and the OMB, includes recommendations that met with a mixed reaction at NASA. Wes Harris, professor of aeronautics and astronautics at the Massachusetts Institute of Technology and the leader of the report, says the NRC fully backs the continued need for flight testing, despite the growth of simulation and other ground-based test techniques.
“This is a path to, an advocate for, and a champion for aeronautics. It advances technology, increases U.S. competitive advantage, improves the balance of trade, creates more skills and jobs [and] reduces the impact of aviation on the environment. It also improves air safety, and we're interested in being a champion for increased efficiency in flight operations,” says Harris.
Although NASA's request for a report was an unusual task for the academy, he says, a broad team of experts was brought in to “recommend how NASA might maintain a robust flight-research program within defined budget scenarios.”
The NRC recommended that the agency should select a “small number [2-5] of focused, integrated, higher-risk, higher-payoff and interdisciplinary programs.” These could be supported by a set of cost-effective flight-test vehicles, each costing $30-50 million per aircraft over three years. This, says the report, could be done “even within the existing budget” but only if the agency eliminates some smaller programs. “NASA should phase out the majority of its lower-priority aeronautic activities,” it adds, without attempting to identify targets.
The NRC found that although the aeronautics budget has shrunk drastically, to less than $600 million today compared with more than $2 billion in the 1990s, the associated workforce has remained more or less the same. The council also found that aeronautics has “become risk-averse and its projects less ambitious, which suggests a decline in our intent to stretch a bit in flight testing,” says Harris. Other criticisms included an “insufficient strategic direction from NASA headquarters.” There is also a need for more programs that “from Day One include flight research.”