X-56A Multi-Utility Technology Testbed

Long, thin, high-aspect-ratio wings are considered crucial to the design of future longrange aircraft, including fuel-efficient airliners and cargo transports. Unlike the short, 

stiff wings found on most aircraft today, 

slender, flexible airfoils are susceptible to 

uncontrollable vibrations, known as flutter, 

and may be stressed by bending forces from 

wind gusts and atmospheric turbulence. 

In order to improve ride quality, efficiency, 

safety and the long-term health of flexible 

aircraft structures, NASA is investigating key 

technologies for active flutter suppression 

and gust-load alleviation. 

Research in these areas is being conducted at 

NASA's Armstrong Flight Research Center 

with the X-56A Multi-Utility Technology 

Testbed, a small, remotely piloted experimental aircraft developed by Lockheed Martin 

Skunk Works for the Air Force Research 

Laboratory (AFRL). In addition, NASA Armstrong will conduct follow-on testing with 

the X-56A to support research on lightweight 

structures and advanced control technologies 

for future efficient, environmentally friendly 

transport aircraft.

The subscale aircraft is 7.5 feet long, has a 

28-foot wingspan, weighs about 480 pounds, 

and is powered by two small 90-pound thrust 

JetCat P400 turbojet engines. 

The modular X-56A system includes two 

center bodies, a set of stiff wings, three sets 

of flexible wings, a ground control station 

and a transportation trailer. The X-56A has 

easily removed wings and is convertible to 

other wing configurations, such as a joinedwing planform or a wing-tail configuration. 

The aircraft is equipped with a ballistic 

parachute recovery system, which is intended 

to recover the fuselage and the majority of 

the aircraft systems in the event of an inflight 

wing failure. 

The initial flight tests of the X-56A system, 

performed by Lockheed and AFRL in the 

latter half of 2013 and extending into early 

2014, collected flight data on highly flexible structures and flutter suppression control 

technology. Initially flown with a conventional stiff wing, the aircraft was subsequently 

used to evaluate active flutter suppression 

with the flexible wings in 2014. NASA Armstrong will juse the X-56A for research into 

lightweight structures and advanced control 

technologies for future efficient, environmentally friendly transport aircraft. 

Under a five-year project supported by the 

The X-56A Multi-Utility Technology Testbed climbs after liftoff from Rogers Dry Lake at Edwards Air Force 

Base during its second test flight (NASA / Ken Ulbrich).
FS-2015-08-105 AFRC

National Aeronautics and Space Administration

Armstrong Flight Research Center

P.O. Box 273

Edwards, California 93523

NASA Facts

Fixed Wing Project of NASA's Fundamental Aeronautics Program, NASA is developing a flexible-wing flight 

control system and advanced sensors to measure wing 

shape and detect airflow separation. The project plans to 

use these to fly the X-56A with a slender, flexible wing 

with a much higher aspect ratio than currently used on 

commercial airliners. Research results from the lowspeed sub-scale X-56A will benefit future designs for 

both subsonic and supersonic aircraft.

Objectives

The goal of the X-56A project is to advance aeroservoelastic technology through flight research using a 

low-cost, modular, remotely piloted aircraft. The aircraft 

is being tested using flight profiles where flutter occurs 

in order to demonstrate that onboard instrumentation can 

not only accurately predict and sense the onset of wing 

flutter, but also be used by the control system to actively 

suppress aeroelastic instabilities. 

Applied to future designs, such technologies will enable 

construction of longer, lighter, more flexible wings for a 

variety of crewed and remotely piloted aircraft. NASA 

engineers will explore issues related to active flutter 

suppression by adjusting software programs in the X56A aircraft’s flight control computer. Researchers also 

expect to learn how to better ease gust loads, which will 

make flexible airplanes safer during encounters with inflight turbulence. Several key goals include:

•	 Maturation of flutter-suppression technologies

•	 Reduction of structural weight to improve fuel

efficiency and range

•	 Increase aspect ratio by 30 to 40 percent to reduce

aerodynamic drag

•	 Promote improved long-term structural integrity by

reducing gust loads

Designing the next generation of aerospace vehicles will 

pose serious challenges in modeling, predicting and controlling potentially destructive aeroservoelastic dynamics 

and finding ways to exploit efficiency gains from lighter, 

more flexible structures.

The wing planform of the 

X-56A shows clearly in this 

view during a low-level flyover (NASA / 

Ken Ulbrich).