When Orville and Wilbur Wright first took flight at Kill Devil Hill in 1903, that event could be interpreted as the first “flight test” of a new aircraft. But by that time the Wrights had conducted numerous other experiments to validate their design—paper studies, wind tunnel tests, even small-scale unpiloted gliders. This was not the first time that a Wright aircraft had sailed into the air. The Wright brothers had performed flight research for years, at a time when the term “flight test” even lacked a definition.
Certainly by modern standards “flight test” does not require a pilot aboard an aircraft. But more importantly, flight testing is not simply the culmination of numerous other tests on the ground—the final death-defying act—rather it is part of a continuum of efforts and experiments necessary to prove a new theory, technology, or aircraft.1 Today flight testing is usually followed by further modeling and simulation and even wind tunnel testing. Often the process of preparing and conducting flight research leads to important unplanned discoveries that can be of great significance, affecting other current and future aircraft designs. For example, in the 1950s the discovery of inertial coupling during flight test of the X-3 experimental aircraft led to changes to the F-104 aircraft already in development.
Flight testing can come in the middle, or even at the beginning, of a research program. In some cases, such as hypersonics research, it is difficult to obtain test data in any other way. In other instances, flight testing is required to validate predictive models. Flight research is a tool, not a conclusion. Failure to conduct flight research can act as a major impediment to the progress of research programs.
There are many methods of conducting aeronautical research. For instance, testing sub-scale models in wind tunnels is a common method. (See Figure 1.1.) Compared to other forms of experimentation, flight research can sometimes be expensive because of the operational and maintenance cost associated with the research airplane. Although some flight testing of small-scale models can be relatively inexpensive, much flight testing will cost at least millions of dollars—for example, putting a new wing or control surface on an existing aircraft or building a small radio-controlled vehicle—and can cost tens of millions of dollars or more for entirely new experimental aircraft.
NASA and its predecessor organization, the National Advisory Committee on Aeronautics (NACA), were responsible for many of the major developments in fundamental aeronautics during the first century of flight.
1 The terms flight test and flight research are used interchangeably throughout this report, but the difference between them is discussed later in this chapter.
This period was marked by U.S. aerospace industry predominance. The agency and its predecessor conducted research across all areas of aeronautics research and development—from computer simulation and modeling to wind tunnel testing to flight testing.
During the past two decades, and particularly in the past decade, NASA’s aeronautics budget has shrunk substantially, from more than $1 billion in 2000 to approximately $570 million in 2010. As a percentage of the NASA budget, aeronautics research has declined from ~7 percent in 2000 to ~3 percent in 2010. (See Table 1.1 and Figures 1.2 and 1.3.)
As Table 1.1 demonstrates, the NASA aeronautics budget has shrunk by approximately 40 percent from 2006 to 2011.2 However, during this same period, the NASA aeronautics civil servant workforce dropped from 1,449 employees in 2006 to 1,371.5 in 2011, or approximately 4 percent (Table 1.2). Thus, a major decrease in funding occurred, but civil servant staffing remained essentially unchanged. At the same time, until 2010, the civil service workforce also received regular wage increases. As a result, the civil service salaries now represent a much greater proportion of NASA’s aeronautics budget than they did in 2006.
The “fixed portion” of the NASA aeronautics research budget related to government personnel and support contractors is 56 percent. Facility maintenance now represents 14 percent of the NASA aeronautics budget by
2 NASA has used different accounting procedures over the years, and the budget figures over that time period have not always included the same categories of expenses. However, there has been a clear decline in both absolute dollars and as a percentage of the overall NASA budget.
TABLE 1.1 Budgets for NASA and NASA Aeronautics for 2000-2011 (in $ millions)
(in $ millions)
(in $ millions)
NOTE: The FY2000 through FY2010 budgets were taken from the enacted columns of the following congressional budget justification documents, but later adjustments may have been implemented. The FY2011 entries reflect the enacted budget from the annual appropriations bill. The years 2000 through 2002 include aerospace technology content, and 2003 through 2011 include only NASA aeronautics. No adjustments have been made to reflect accounting changes or inflation. Thus, it is not possible to make an accurate year-to-year comparison with this data, but overall trends are apparent.
expense category. (See Figure 1.4.) The fixed cost for salaries and facilities severely limits the resources that can be effectively committed to flight research programs for building the aircraft and hiring the contractors to work on them. One of the results of the overall aeronautics budget decrease has been the elimination of much flight research from NASA’s aeronautics portfolio. Although NASA does continue some flight research, it lacks sufficient funding and focus to conduct flight research in more than a few relatively low-level efforts. (See Box 1.1.)
NASA’s aeronautics research program funding has declined to the point that the agency is unable to advance many projects from the simulation/modeling and/or wind tunnel stage to the flight research stage, and the flight research projects it currently undertakes are not ambitious. Numerous aeronautics projects at NASA cannot advance to become demonstrated or usable technologies unless they are demonstrated in flight research. And because flight research is required to validate models and other research tools, the lack of flight research as an option can cause
research projects to collapse or continue at a nonproductive or inefficient level. The end result has been an aeronautics research program that can no longer make substantial progress in many areas, not simply flight research alone.
There has been an additional effect caused by the decreased funding that is measured by what officials at Dryden Flight Research Center refer to as the “X-factor.” A program’s overall X-factor is calculated by multiplying the program’s ranking in three categories: discovery, complexity/risk, and national benefit. As the NASA aeronautics budget has decreased, so too has the X-factor of the programs in flight test. (See Table 1.3 and Figure 1.5.)
The X-factor rating refers only to aircraft programs. But aeronautics encompasses more than flying vehicles, and NASA’s Integrated Systems Research Program reflects the fact that increasingly highly complex systems (for instance, unpiloted aircraft and the National Airspace System) are being combined. But although the committee did not evaluate the specific calculations used in each X-factor assessment, it agreed with this general characterization of NASA flight research. It was clear from the committee’s review of current and past flight research projects that their technological difficulty and ambition have decreased substantially. For example, most NASA flight research projects that the committee saw firsthand at Dryden Flight Research Center or heard about during briefings are component-level tests, not tests of entire systems.
The committee concluded that this lack of a set of ambitious flight research activities is not simply due to a scarcity of resources but is also the result of a risk-averse culture within the NASA aeronautics program, a reality conceded by several NASA officials in their presentations to the committee. NASA aeronautics no longer seeks to do bold projects that could fail. Because tight budgets lead managers to become averse to risks that could destroy their smaller projects, the aeronautics program has focused on small and uncontroversial projects.
Risk-aversion is hard to quantify, but it manifests itself in various ways. For example, Dryden Flight Research Center helped to create a small unmanned aerial vehicle (UAV) range at Edwards Air Force Base to make it easier to fly small and low-energy vehicles without all of the cost and weight of all the redundant tracking and termination systems. The small UAV airspace is an area over the lake bed near the Edwards North base runway, which is well away from populated areas. This is the area in which NASA’s X-48B has been conducting its flights, and this is the area to take risk in. But increasingly NASA has been imposing greater restrictions on the operation of small UAVs in this dedicated area. The X-48B has two GPS units and a Mode C transponder as well as a dual flight
|Actmaulica Pall Time Equivalentsa||2006||2007||2008||2009||2010||2011|
a Essentilly full time: employees, i.e. civil service employees.
The Aeronautics Research Mission Directorate (ARMD) research plans for fiscal year (FY) 2012 include the following flight research activities. NASA has defined the content the agency considers to be related to flight research.
Aeronautics Test Program (ATP)—approximately $26 million
The flight operations and test infrastructure consists of an integrated set of elements, including the Western Aeronautical Test Range, which support aircraft maintenance and operations and the testbed aircraft that provide the resources required for research flight and mission support projects. ATP provides up to 100 percent of the facility fixed costs for these flight facilities to ensure facility and staff availability. The activity also includes the simulation and flight loads laboratories, a suite of ground-based laboratories that support research flight and mission operations. ATP provides up to 20 percent of the fixed costs for laboratories, ensuring facility and staff availability.
Fundamental Aeronautics Program—approximately $10 million
The Fundamental Aeronautics Program’s planned investment in flight research includes expenses related to flights occurring in FY2012 and expenses for long-lead preparations for flights expected to occur in FY2013. The investment includes flight testing of critical advanced technologies for future air vehicles as well as important fundamental scientific data necessary for code development and prediction validation. Research will be conducted on advanced technologies related to low-boom supersonic aircraft design, and preparations for the fixed wing alternative fuels in-flight emissions tests and rotorcraft acoustic flight tests will continue.
Aviation Safety Program (AvSP)—approximately $10 million
AvSP’s flight research estimate includes everything surrounding the High Ice Water Content (HIWC) Flight Campaign, the operation of AiRSTAR (Airborne Subscale Transport Aircraft Research) for the program’s research efforts, and smaller health management and prognostics experiments on real flying assets in order to learn what happens in relevant environments.
Integrated Systems Research Program (ISRP)—approximately $16 million
The ISRP investment in flight research will include flight research with the X-48C and the GIII, both operated out of Dryden Flight Research Center. The ISRP will also prepare for, conduct, and analyze flight tests on the Ikhana aircraft, also at Dryden, for the uninhabited aerial system project.
termination system. This is a significant amount of backup equipment simply to allow the vehicle to fly within a restricted area inside a restricted area.
Risk is also a major factor in considering the use of UAVs in the National Airspace System. However, if NASA already demonstrates aversion to risk within the Edwards small UAV range, the agency may find it difficult to make the larger leaps required to develop UAVs that can operate outside highly restricted airspace.
Certainly safety is of high importance for any research program, but the problem at NASA—which is apparently not unique to the agency and can be seen in other research organizations as well—is fear of suffering the setbacks or problems that are the normal result of tackling complex challenges and seeking bold goals.
Formal study of aeronautics as the science behind the design, manufacturing, and operations of flight-capable machines is generally attributed to Sir George Cayley in the 18th century. His thoughtful studies on the physics
= fn (modification and modeling)
= fn( integration)
= fn(mission/industry benefit)
Unique, new aircraft
New analysis and models necessary for performance predictions
Innovative, unique approach to complex cyber-human-systems interactions, never done before
Significant risk, outcome uncertain until demonsrralcd in flight
|Enables new industry
Enables new mission
High national visibility
Add a new system to existing aircraft
Moderate reliance on modified Existing analysis it performance models
New approaches with multiple exisiting aircraft needed
|Improves existing mission
Additional industry capability
Makes mission safer or more efficient
Add a sensor to existing aircraft
|Improving research capability|
No analysis or aircraft model changes required
Well-known flight test approach
|Single interdisciplinary interest|
NOTE: An X-faclor of 3 is the most difficult level and also the most expensive.
of flight developed an organized approach to aeronautical research. He introduced the terms “lift” and “drag,” considered the concept of center of gravity, introduced using a tail surface for control, and imagined various forms of propulsion.
Whereas much of Cayley’s research was theoretical, the Wright brothers, on their own, developed a systematic approach to decomposing the mechanics of flight into various parts of their machine. They discussed theories about each part’s contribution to lift, drag, or control. They designed a course of parametric research to understand the strength or weakness of those theories. First they used sub-scale components tested in a wind tunnel and then took the best designs and integrated them into the “Flyer” for flight test. Discoveries in this flight test led to additional research and improvements in the design of the Flyer.
This is, in essence, the aeronautical research process used today. Flight research, however, has always been a necessary component, and there is no substitute for flying. Wilbur Wright wrote to his family in 1899, “If you are looking for perfect safety you will do well to sit on a fence and watch the birds; but if you really wish to learn, you must mount a machine and become acquainted with its tricks by actual trial.”3 Today, such things are feasible in the course of planning and conducting aeronautics research. The process has become more complex with the advent of computers and sophisticated software modeling of the physics of aerodynamics, thermodynamics, and a multitude of other branches of the physical sciences. Finally, as the introduction of unpiloted air vehicles grows, we are facing the complexity of research to understand, model, and test the interactions of autonomous systems into a world of human-operated and human-managed systems.
As new technology comes along, new discoveries and innovation in their use in aeronautics can bring significant vitality to an industry that provides aircraft for commercial, military, and civil uses, powering the economies and security of nations. For example, NASA sponsored application of Apollo digital flight computers into aircraft that revolutionized both military and commercial cockpits and aircraft capabilities. Many examples exist in materials research, with chemistry and biology recently providing alternative energy sources for aviation. This well-rehearsed method of individual creativity, government sponsorship, and industrial partnership continues to be an effective course for bringing discovery and innovation in aircraft to the marketplace, both commercial and military. The U.S. aviation industry and the Department of Defense (DOD) still see an important role for NASA to play in advancing U.S. aeronautics capabilities. (See Chapter 3 for further details.)
There are examples from other areas of aeronautics research that demonstrate the interactive and co-dependent aspects of the research effort. For example, recent studies have demonstrated that computational fluid dynamics conducted on powerful computers still cannot entirely replace wind tunnels.4 Similarly, wind tunnels have been unable to entirely replace flight testing. Simulation and modeling, wind tunnels, and flight test are the three legs that support effective aeronautics research—remove one and the research effort collapses.
Today it is critical to understand systems operations and systems safety of the complex orchestration of humans and machines. Can we completely rely on laboratories, supercomputers (for computational fluid dynamics), and ground-based test facilities for the results on which to base future decisions in policy, economics, safety, and security? Or are flight research and flight testing still an essential part of aeronautics research? When and how much flight research is needed are important elements to address.
Flight Research and Flight Test
Throughout this report the terms “flight research” and “flight test” are used. However, they are not strictly synonymous, although they share similar characteristics. For example, in each of the flight research and flight test sub-elements, a common methodology is used, for the most part. That is, pilots and engineers prepare a test matrix, data acquisition systems collect data from instruments, on-board processing and telemetry of flight and test data to ground stations allow for more rigorous data processing, and control rooms are filled with engineers reviewing and managing the test processes and overseeing both aircraft and range safety. (See Figure 1.6.)
3 H. Combs, Kill Devil Hill, Houghton Mifflin Company, Boston, Mass., 1979, p. 74.
4 NASA, Role of Computational Fluid Dynamics and Wind Tunnels in Aeronautics R&D, NASA/TP-2010-000000, NASA, July 2010.
Where flight research and flight test differ is not necessarily in how they are conducted, but in their purpose. The principal purpose of flight test is to prove that an aircraft performs within predicted, nominal ranges of performance; if it does not, then one seeks to understand why not. In commercial and military practice, flight test is used to determine if the flight vehicle, as delivered, meets the expectations of customer-defined requirements. An excellent example is the F-35 series of fighter aircraft currently undergoing flight testing by the branches of DOD. The F-35 is developed and in low-rate production. Flight testing under way at Edwards Air Force Base and elsewhere is intended to evaluate the performance characteristics of the aircraft and to expand its capabilities.
Flight research on the other hand has a multitude of purposes, such as advancing fundamental understanding of vortical flows of aircraft flying at high angles of attack (such as NASA’s High Alpha Program); validating wind tunnel flow quality (for example, the USAF/NASA 15° Cone Probe Experiments); proving the viability of new technologies (such as the USAF F-15 STOL and Maneuver-thrust vectoring nozzles and X-53 Active Aeroelastic Wing) and new aircraft concepts (X-29 Forward Swept Wing); understanding and improving multi-aircraft interoperations (for example, Autonomous Formation Flight or Unmanned Air Vehicle Sense and Avoid); and evaluating and validating complex interactive systems and intelligent/adaptive systems and instrumentation and autonomy. In addition to pushing the research envelope, flight research plays a major role in reducing risk. Putting a research aircraft in the air allows the exploration of technologies and principles that would be far more costly to work out in an operational program. In the committee’s view, in recent years DOD has devoted a far greater percentage of its resources to flight testing already developed vehicles than to conducting flight research. This has occurred at the same time that NASA’s aeronautics budget has decreased substantially. The result is that the United States as a whole conducts less flight research today than it has in the past.
Flight research can be conducted using new purpose-built vehicles or by the modification of existing aircraft (see Figure 1.7). To this end, NASA has a large stable of aircraft. Although the NASA aircraft fleet is large, many
of these aircraft are used to support NASA’s Science Mission Directorate or human spaceflight missions, such as the ER-2 and WB-57 high-altitude research aircraft and the T-38N trainers, not flight research programs. Part of the committee’s statement of task asks if the fleet of NASA aircraft has the capability to meet the requirements of NASA’s current and future research. The list of flight assets in Appendix A is extensive, and some of the aircraft used to support other missions could also be adapted to conduct aeronautics research. However, few of NASA’s flight research aircraft were purpose-built to conduct flight research. NASA currently lacks new, purpose-built aircraft or aircraft that can be modified for specific testing such as testing of un-ducted fan propulsion systems that may lead to future highly efficient air vehicles. NASA’s current flight research programs are limited to relatively low-cost flight experiments and demonstrations that have to deal with the limitations of the available aircraft, and today these flight research programs represent less than 12 percent of the current NASA aeronautics research budget.
In a budget-constrained environment it is often necessary to fit the size of the experiment to the budget and not the budget to the size of the experiment. This is called “cost as an independent variable design.” A historic cost trend of some research and development aircraft programs is shown in Figure 1.8. The almost linear relationship when presented on logarithmic scales demonstrates that cost can be exponentially decreased by reducing the empty weight of the aircraft. Cost as an independent variable can be used when the phenomenon under investigation is not size dependent, or if the relationship to size is well understood and can therefore be compensated for in the results. The lowering of the cost of the development and manufacturing of a research vehicle can allow the investigator to perform higher-risk testing. Often testing at the edge of a flight limit can provide much greater insight than can safely working away from the edge of the flight envelope. This is an argument for reducing the size of a research vehicle to the smallest size that still allows the research to be of a valid scale. However, it does not automatically lead to the choice of a UAV over a piloted vehicle, and some small experimental aircraft have still been piloted (for instance, Boeing’s Bird of Prey). However, making a vehicle unpiloted allows taking a vehicle closer to the ultimate limits of its flight envelope.
NASA’s Aeronautics Research Mission Directorate
ARMD is NASA’s aeronautics research arm. It is guided by five core principles:5
• Valuing innovation and technical excellence;
• Aligning research to ensure a strong relevance to national needs;
• Transferring technology in a timely and robust manner;
• Maintaining strong partnerships with other government agencies, industry, and academia; and
• Inspiring the next generation of engineers and researchers.
However, these five principles guide but do not fully align ARMD with the goals of the nation. A number of documents and policies have been put in place to establish the goals. These documents include the NASA charter documents, the National Research Council’s Decadal Survey of Civil Aeronautics,6 the “National Aeronautics Research and Development Policy,” 7 the “National Plan for Aeronautics Research and Development,” 8 and “Vision 100—Century of Aviation Reauthorization Act and the Integrated Work Plan,” 9 to name just a partial list. From these external documents and within the confines of the yearly congressional budget authorization NASA, as a whole, and specifically ARMD, must develop internal goals.
The committee concluded early in its deliberations that NASA’s current aeronautics research budget is not adequate to properly address the 51 highest-priority research and technology (R&T) challenges from the 2006 decadal survey of civil aeronautics. That list is simply too large to be meaningful. It is apparent that NASA has achieved limited progress relative to many of these goals, and NASA aeronautics is not well positioned to successfully execute these challenges within the existing resource constraints. The decadal survey examined the U.S. air transportation system for research and technologies that would advance four objectives: increase capacity, improve safety and reliability, increase efficiency and performance, and reduce energy consumption and environmental impact. The survey also stated the need to account for other strategic objectives, including national and homeland security and the support of the space program.
The decadal survey presented its findings of 51 highest-priority challenges in five areas: aerodynamics and aeroacoustics (11 challenges); propulsion and power (10 challenges); materials and structures (10 challenges); dynamics, navigation, and control and avionics (10 challenges); and intelligent and autonomous systems, operations, and decision making, human integrated systems, and networking and communications (10 challenges).
The decadal survey listed eight recommendations (see Box 1.2). Recommendation 7 states that “NASA should consult with non-NASA researchers to identify the most effective facilities and tools applicable to key aeronautics R&T projects and should facilitate collaborative research to ensure that each project has access to the most appropriate research capabilities, including test facilities; computational models and facilities; and intellectual capital, available from NASA, the Federal Aviation Administration, the Department of Defense, and other interested research organizations in the government, industry, and academia” (p. 3). Often the most appropriate test facility is one in flight.
The executive summary of the decadal survey also includes four points of encouragement. The fourth of these points asks NASA to “invest in research associated with improved ground and flight test facilities and diagnostics, in coordination with the DOD and industry.”
5 J. Shin, “NASA Aeronautic Research,” briefing to the National Research Council Committee to Assess NASA’s Aeronautics Flight Research Capabilities, April 18, 2011, Edwards, Calif., slide 16.
6 National Research Council, Decadal Survey of Civil Aeronautics: Foundation for the Future, The National Academies Press, Washington, D.C., 2006.
7 National Science and Technology Council, “National Aeronautics Research and Development Policy,” Office of Science and Technology Policy Washington, D.C., December 2006, available at http://www.aeronautics.nasa.gov/releases/national_aeronautics_rd_policy_dec_2006.pdf.
8 National Science and Technology Council, “National Plan for Aeronautics Research and Development,” Office of Science and Technology Policy, Washington, D.C., December 2007, available at http://www.aeronautics.nasa.gov/releases/aero_rd_plan_final_21_dec_2007.pdf.
9 108th Congress, Public Law 108-176, December 12, 2003.
Recommendations to Achieve Strategic Objectives for Civil Aeronautics Research and Technology
1. NASA should use the 51 Challenges listed in Table ES-1 as the foundation for the future of NASA’s civil aeronautics research program during the next decade.
2. The U.S. government should place a high priority on establishing a stable aeronautics R&T plan, with the expectation that the plan will receive sustained funding for a decade or more, as necessary, for activities that are demonstrating satisfactory progress.
3. NASA should use five Common Themes to make the most efficient use of civil aeronautics R&T resources:
• Physics-based analysis tools
• Multidisciplinary design tools
• Advanced configurations
• Intelligent and adaptive systems
• Complex interactive systems
4. NASA should support fundamental research to create the foundations for practical certification standards for new technologies.
5. The U.S. government should align organizational responsibilities as well as develop and implement techniques to improve change management for federal agencies and to assure a safe and cost-effective transition to the air transportation system of the future.
6. NASA should ensure that its civil aeronautics R&T plan features the substantive involvement of universities and industry, including a more balanced allocation of funding between in-house and external organizations than currently exists.
7. NASA should consult with non-NASA researchers to identify the most effective facilities and tools applicable to key aeronautics R&T projects and should facilitate collaborative research to ensure that each project has access to the most appropriate research capabilities, including test facilities; computational models and facilities; and intellectual capital, available from NASA, the Federal Aviation Administration, the Department of Defense, and other interested research organizations in government, industry, and academia.
8. The U.S. government should conduct a high-level review of organizational options for ensuring U.S. leadership in civil aeronautics.
SOURCE: National Research Council, Decadal Survey of Civil Aeronautics: Foundation for the Future, The National Academies Press, Washington, D.C., 2006, p. 3.
There are five common threads from the 51 highest-priority research and technology challenges. These are (1) physics-based analysis tools to enable analytical capabilities that go far beyond existing modeling and simulation capabilities and reduce the use of empirical approaches; (2) multidisciplinary design tools to integrate high-fidelity analyses with efficient design methods and to accommodate uncertainty, multiple objectives, and large-scale systems; (3) advanced configurations to go beyond the ability of conventional technologies and aircraft to achieve strategic objectives; (4) intelligent and adaptive systems to significantly improve the performance and robustness of aircraft and the air transportation system as a whole; and (5) complex interactive systems that include system-wide information management for all airspace users, and intelligent systems for unpiloted systems that can be used for information collection.
While the specific single-discipline technology development as described in the 2006 decadal survey is important, the full promise of these developments cannot be realized until they have been integrated into the complete multidisciplinary system in a representative environment that only flight research can provide. The true measure of success in overcoming the technological challenges is not strictly the technology itself but the ability to integrate
it and to achieve Federal Aviatin Administration certification and to manage the ramifications of the changes to both the internal and external systems.
ARMD has created an organizational structure to work toward the accomplishment of these goals. Figure 1.9 depicts ARMD, which is organized into 5 major programs and 12 major projects within them. The projects themselves are also made up of many sub-projects and studies. Cross-cutting the programs are the engineering disciplines grouped into branches. These programs are worked by engineers and technicians across four major NASA centers. These centers and their roles within ARMD are described later in this chapter.
NASA ARMD Programs
The five major programs that make up the ARMD organization are the Aviation Safety Program, the Airspace Systems Program, the Fundamental Aeronautics Program, the Integrated Systems Research Program, and the Aeronautics Test Program. A brief description of the programs is presented below, and a more detailed description of each of the programs within ARMD and the projects within each program is presented in Appendix B. For each of the programs described in Appendix B, a short discussion of flight research being conducted within the program is presented along with past and projected budget information.
Aviation Safety Program
The Aviation Safety Program is tasked with ensuring system-wide safety, maintaining and improving vehicle safety in key areas, and dealing with the presence of atmospheric risk.
Airspace Systems Program
The Airspace Systems Program is charged with the development of core concepts and technologies to improve the throughput of the National Airspace System, and the integration, evaluation, systems analysis, and transition of these core concepts and technologies into the Next Generation air traffic management system (NextGen).
Fundamental Aeronautics Program
The Fundamental Aeronautics Program is divided into flight regimes: subsonic fixed wing, subsonic rotary wing, supersonics, and hypersonics. The program’s purpose is to conduct fundamental research to improve aircraft performance and minimize environmental impacts; radically improve the civil effectiveness of rotary wing vehicles by increasing speed, range, and payload while decreasing noise and emissions; explore advanced capabilities and configurations for low-boom supersonic aircraft; and conduct foundational hypersonic research to enable new capabilities.
Integrated Systems Research Program
The Integrated Systems Research Program is the parent organization for large multidisciplinary projects. The two current projects are the Environmentally Responsible Aviation (ERA) project to reduce the environmental impact of aviation by reducing fuel burn, noise, and emissions and the Uninhabited Aerial System (UAS) integration in the National Airspace System (often abbreviated as “UAS in the NAS”). ERA is discussed in detail in Chapter 2. The UAS has the goal of demonstrating an integrated system in a relevant environment that will allow for safe operations of unpiloted vehicles. This demonstration and other experiments will be the basis for updating regulations to allow for routine operation of unpiloted vehicles in the national airspace. This is another area where there are potentially great gains to be made, but where questions of risk—such as operating unpiloted aircraft in heavy air traffic corridors—will pose significant challenges.
Aeronautics Test Program
The purpose of the Aeronautics Test Program is to strategically manage NASA’s ground and flight assets to meet national aerospace testing requirements.
Role of the NASA Field Centers
Although ARMD is divided into programs and projects, ARMD’s work is also spread among four major centers located throughout the country (see Box 1.3). These centers are Ames Research Center, located in Moffett Field, California; Dryden Flight Research Center, located in Edwards, California; Glenn Research Center, located in Cleveland, Ohio; and Langley Research Center, located in Hampton, Virginia. These centers perform significant amounts of non-aeronautics research, although Dryden is primarily focused on aeronautics research. Each of the centers has specific key aeronautics capabilities, but there is no specific alignment of programs and projects and centers. For instance, the ERA project is hosted at Langley Research Center, and its chief engineer is located at Dryden Flight Research Center.
What this ARMD overview demonstrates is that even though aeronautics represents only 3 percent of NASA’s overall budget, aeronautics research at NASA is part of a complex structure of five major programs spread over four geographically diverse field centers. It is further divided into numerous individual projects. Collectively, they are pursuing the long list of challenges outlined in the 2006 decadal survey of civil aeronautics.10 (These programs are further described in Appendix B.)
The committee concluded that this complexity was part of the problem. NASA’s aeronautics budget dropped substantially in the past decade, and yet there was no consequent reduction in field centers and facilities or personnel, therefore resulting in a consequent substantial increase in the percentage of fixed costs. The percentage of the aeronautics budget going to fixed costs is substantial, as is the number of individual research projects that aeronautics is undertaking. The end result is that the aeronautics program overall appears to be spread very thin, and flight research is one of the areas to suffer.
The solution to this situation is not automatically to increase funding for the aeronautics budget, although the committee notes that even a modest shift of only 1 percent of NASA’s budget to aeronautics could allow
10 NRC, Decadal Survey of Civil Aeronautics, 2006.
Ames Research Center
Ames Research Center was established on December 20, 1939, in Moffett Field, California. In general, its research concentrates on technology development for NASA missions as well as supercomputing, networking, intelligent systems, and air traffic management. Ames produces advances in nanotechnology, space biology, biotechnology, and aerospace and thermal protection systems. It also researches astrobiology and the influence of gravity on living systems.
Dryden Flight Research Center
Dryden Flight Research Center has been located in Edwards, California, since 1949. The remote location and clear weather are ideal for the year-round testing of new aerospace vehicles. Most of Dryden’s research is focused on aeronautics. Today it employs 550 research personnel and has a yearly budget of about $60 million. Dryden operates a number of aircraft in support of ARMD programs, including F-15s and F-18s in support of the subsonic fixed wing and supersonic projects within the Fundamental Aeronautics Program. Dryden, because of its experience in modifying aircraft for aeronautics research and its location, also supports many aircraft for other mission directorates within NASA. In addition to its flight research in support of NASA’s safety program, Dryden operates the Stratospheric Observatory for Infrared Astronomy as well as other airborne science aircraft. Dryden has long been the location where much of NASA’s flight research has been conducted because of the controlled airspace and good weather associated with the Mojave Desert. (See Figure 1.3.1.)
Glenn Research Center
Originally instituted in 1941 in Cleveland, Ohio, Lewis Research Center was later renamed for John H. Glenn. The Glenn Research Center focuses on the development of various aeronautic technologies, including air-breathing propulsion and cryogenic fluid management. The center makes advances in communications technology, in-space propulsion, and power and energy storage and conversion, while also investigating materials, structures, and biomedical technologies to be implemented in the harsh space environment.
Langley Research Center
In 1921 Langley Research Center was opened in Hampton, Virginia, as the nation’s first aeronautics laboratory. Langley’s modern contributions include designing supersonic and hypersonic aircraft and advancing the atmospheric sciences. In addition, the center works to improve the safety and efficiency of both civilian and military aircraft.
for several flight research projects to begin to make progress rather than stagnate. However, the committee determined that even a refocusing of efforts, from numerous small projects that are too small to have sufficient resources to progress to flight research to fewer larger ones that do receive resources for flight research, would enable them to move into their next stages. This refocusing will, by necessity, require stopping lower-priority work and moving personnel and funds to concentrate resources. The committee is not advocating that NASA pursue research projects that equal the cost or ambition of the X-15 program. However, at the moment, the aeronautics program is spread over many projects that never actually result in flyable hardware, or that are small and unambitious.
It was not possible for the committee to address all of the different aspects of NASA’s aeronautics research effort because of time and resource constraints. Such a comprehensive overview is more appropriate to a broad-based survey of the entire NASA aeronautics program. NASA conducts flight research in other areas such as air traffic control, aviation safety, and vertical flight (i.e., rotorcraft), and the committee did receive briefings about
them. For example, several committee members visited the Ames Research Center, where they witnessed an air traffic control simulation in progress and also met with Ames personnel working with the U.S. Army on issues such as carrying external slung loads on Army helicopters and simulations of future large civil rotorcraft.
For this study the committee selected three projects—the Supersonics and Hypersonics projects from the Fundamental Aeronautics Program and the ERA project from the Integrated Systems Research Program—to serve as case studies demonstrating NASA’s activities and the role that flight research takes, or could take, in these research programs. ERA is a relatively new project addressing the integration of technologies and should map to the challenges outlined in the 2006 decadal survey. This project offered the committee the chance to examine how NASA matures and integrates systems. The examination of the ERA project also enabled the committee to look for commonality with the subsonic fixed wing project within the Fundamental Aeronautics Program. Both the Supersonics and the Hypersonics projects were chosen to examine how these fundamental research projects actually used flight research. In the case of the Hypersonics project, there was a desire by the committee to examine the use of flight versus ground-based testing.
Aeronautics research is important to the United States and its national security, both militarily and economically. Flight research is a critical part of this aeronautics research, not only to validate predictive tools, but also for the knowledge gained in the process of integrating systems and the possibility of discovery. ARMD is charged with advancing the aeronautical sciences in support of the military and industry. Despite these goals, NASA does not currently include economic development of the aerospace industry as one of its primary objectives.
NASA’s aeronautical research priorities are derived from multiple documents, reports, and policy statements, and constrained by budget and congressional authorizations. The numbers of “priorities” are numerous, including 51 research and technology challenges from the 2006 NRC decadal survey of civil aeronautics11 alone. The reductions in the ARMD budget over the past decade and the increase in the number of these priorities have led to a reduction in the amount of budget available for each individual technology to the point that very few projects can advance enough to begin even the most modest flight research.
In many cases flight research is the only way to advance certain technologies. This is because of the lack of ground facilities capable of replicating the environment or the physical laws that govern the phenomenon under study. ARMD is conducting aeronautics flight research throughout its organization; however, in most cases the technical difficulty of this flight research is of very low X-factor. NASA no longer conducts the same kind of technologically challenging flight research that the agency performed only a decade ago and no longer produces the kinds of aeronautical advances that have made the United States a world leader in aviation.
NASA’s guiding principles charge the agency with aligning its goals with the nation’s critical needs. DOD for instance, to meet its military operational requirements, must perform portions of its missions in the supersonic flight regime and, to a limited extent, in the hypersonic regime. Commercial crew development vehicles currently being built to reach the International Space Station and NASA’s exploration beyond Earth require exiting and reentering Earth and planetary atmospheres. Such vehicles will need to fly across all speed regimes (subsonic, supersonic, and hypersonic). Therefore, in order for NASA to address these critical national needs, it must maintain strong leadership capabilities in all speed regimes of flight.
ARMD is organized into a series of programs and projects within the programs that are meant to provide structure to address specific priorities. ARMD also provides branch organizations to support engineering disciples and other support functions. The shear number of these programs, projects, sub-projects, branches, and centers leads to organizational inefficiencies. With reduced budgets, a constant number of civil service employees and contract employees, fixed facilities and other costs, an increased proportion of funds is not available for spending on flight research efforts. The result is an aeronautics research effort that is diluted and diminished and unable to advance any research agendas.
Finding: The Aeronautics Research Mission Directorate is charged with performing aeronautics research, including flight research in support of the nation’s needs. The United States currently needs aeronautics research for the national defense both militarily and economically. The 2006 NRC report Decadal Survey of Civil Aeronautics: Foundation for the Future identified 51 high-priority civil challenges that NASA is pursuing. This number is too high to achieve meaningful progress given existing resources. With the large number of “high-priority” projects, ARMD appears to be avoiding flight research because of the perceived cost of flight test and what has become a risk-averse culture.
Recommendation: NASA should select and implement at any given time a small number (two to five) of focused, integrated, higher-risk, higher-payoff, and interdisciplinary programs. The committee concluded that these priority focused efforts will require flight testing to advance useful knowledge and should therefore include a path to flight. Therefore, NASA should also develop cost-effective flight research vehicles to demonstrate innovative aerospace technology in flight. A new innovative air vehicle should be launched each year. To make meaningful progress in these programs the scope
11 NRC, Decadal Survey of Civil Aeronautics, 2006.
of activity for each vehicle research program would be on the order of $30 million to $50 million total per vehicle over a 3-year period—that is, $10 million to $15 million per vehicle per year. The priority focused programs should be drawn from the research areas identified by the 2006 NRC decadal survey of civil aeronautics, in order to achieve progress for fundamental aeronautics as well as other relevant related military requirements. To implement this recommendation without additional funding for ARMD, NASA should phase out the majority of its lower-priority aeronautics activities.
The committee notes that “focused, integrated, higher-risk, higher-payoff, and interdisciplinary programs” does not mean “aircraft” or “vehicles.” Indeed, a new program, such as one to advance research in an area such as UASs in the National Air Space, could require several relatively small UAVs. Furthermore, new innovative air vehicles do not have to be piloted, nor do they have to be “flagship” class, but they could be relatively small unmanned systems. Finally, the committee concluded that additional funding for aeronautics could enable more of these programs (i.e., four to five) to be selected and implemented, but that it is possible to begin making progress by re-prioritizing and phasing out lower-priority aeronautics activities.
The purpose of introducing new and innovative vehicles is to enable NASA to return to its role of fostering advances in U.S. aeronautics, as established in the agency’s original charter, which is something that NASA cannot achieve without actually reviving its once active and productive flight research capabilities.
The basis for this recommendation is further illuminated in the chapters that follow, which focus on a subset of the agency’s numerous aeronautics research programs and discuss the value of focusing them on a few higher-risk and higher-payoff programs with a path to flight research.