Unmanned Aircraft Systems: Use in the National Airspace System and the Role of the Department of Homeland Security
Released: 2012-07-19T00:00:00

Letter

Background

Current domestic uses of UAS are limited and include law enforcement, monitoring or fighting forest fires, border security, weather research, and scientific data collection. UAS have a wide-range of potential uses, including commercial uses such as pipeline, utility, and farm fence inspections; vehicular traffic monitoring; real estate and construction site photography; relaying telecommunication signals; and crop dusting. FAA’s long-range goal is to permit, to the greatest extent possible, routine UAS operations in the national airspace system while ensuring safety. Using UAS for commercial purposes is not currently allowed in the national airspace. As the list of potential uses for UAS grows, so do the concerns about how they will affect existing military and non-military aviation as well as concerns about how they might be used.

Domestically, state and local law enforcement entities represent the greatest potential use of small UAS in the near term because small UAS can offer a simple and cost effective solution for airborne law enforcement activities for agencies that cannot afford a helicopter or other larger aircraft. For example, federal officials and one airborne law enforcement official said that a small UAS costing between $30,000 and $50,000 is more likely to be purchased by state and local law enforcement entities because the cost is nearly equivalent to that of a patrol car. According to recent FAA data, 12 state and local law enforcement entities have a Certificate of Waiver or Authorization (COA) while an official at the Department of Justice said that approximately 100 law enforcement entities have expressed interest in using a UAS for some of their missions. According to law enforcement officials with whom we spoke, small UAS are ideal for certain types of law enforcement activities. Officials anticipate that small UAS could provide support for tactical teams, post-event crime scene analysis and critical infrastructure photography. Officials said that they do not anticipate using small UAS for routine patrols or missions that would require flights over extended distances or time periods.

FAA has been working with the Department of Justice’s National Institute of Justice to develop a COA process through a memorandum of understanding to better meet the operational requirements of law enforcement entities. While the memorandum of understanding establishing this COA process has not been finalized, there are two law enforcement entities that are using small UAS on a consistent basis for their missions and operations. The proposed process would allow law enforcement entities to receive a COA for training and performance evaluation. When the entity has shown proficiency in operating its UAS, it would then receive an operational COA allowing it to operate small UAS for a range of missions. In May 2012, FAA stated that it met its first requirement to expedite the COA process for public safety entities. FAA’s reauthorization also required the agency to enter into agreements with appropriate government agencies to simplify the COA process and allow a government public safety agency to operate unmanned aircraft weighing 4.4 pounds or less if flown within the line of sight of the operator, less than 400 feet above the ground, and during daylight conditions, among others stipulations.

Obstacles to Safe and Routine Integration of UAS

In 2008, we reported that UAS could not meet the aviation safety requirements developed for manned aircraft and posed several obstacles to operating safely and routinely in the national airspace system.

Sense and avoid technologies. To date, no suitable technology has been identified that would provide UAS with the capability to meet the detect, sense, and avoid requirements of the national airspace system. Our ongoing work indicates that research has been carried out to mitigate this, but the inability for UAS to sense and avoid other aircraft or objects remains an obstacle. With no pilot to scan the sky, UAS do not have an on-board capability to directly “see” other aircraft. Consequently, the UAS must possess the capability to sense and avoid an object using on-board equipment, or with the assistance of a human on the ground or in a chase aircraft, or by other means, such as radar. Many UAS, particularly smaller models, will likely operate at altitudes below 18,000 feet, sharing airspace with other vehicles or objects. Sensing and avoiding other vehicles or objects represents a particular challenge for UAS, because other vehicles or objects at this altitude often do not transmit an electronic signal to identify themselves and, even if they did, many small UAS, do not have equipment to detect such signals if they are used and may be too small to carry such equipment.

Command and control communications. Similar to what we previously reported, ensuring uninterrupted command and control for UAS remains a key obstacle for safe and routine integration into the national airspace. Without such control, the UAS could collide with another aircraft or crash, causing injury or property damage. The lack of dedicated radiofrequency spectrum for UAS operations heightens the possibility that an operator could lose command and control of the UAS. Unlike manned aircraft that use dedicated radio frequencies, non-military UAS currently use undedicated frequencies and remain vulnerable to unintentional or intentional interference. To address the potential interruption of command and control, UAS generally have pre-programmed maneuvers to follow if the command and control link becomes interrupted (called a “lost-link scenario”). However, these procedures are not standardized across all types of UAS and, therefore, remain unpredictable to air traffic controllers who have responsibility for ensuring safe separation of aircraft in their airspace.

Standards. A rigorous certification process with established performance thresholds is needed to ensure that UAS and pilots meet safety, reliability, and performance standards. Minimum aviation system standards are needed in three areas: performance; command and control communications; and sense and avoid. In 2004, RTCA, a standards-making body sponsored by FAA, established a federal advisory committee called the Special Committee 203 (or SC 203), to establish minimum performance standards for FAA to use in developing UAS regulations. Individuals from academia and the private sector serve on the committee, along with FAA, NASA, and DOD officials. ASTM International Committee F38 on UAS, an international voluntary consensus standards-making body, is working with FAA to develop standards to support the integration of small UAS into the national airspace.

Regulations. FAA regulations govern the routine operation of most aircraft in the national airspace system. do not contain provisions to address issues relating to unmanned aircraft. As we highlighted in our previous report, existing regulations may need to be modified to address the unique characteristics of UAS. Today, UAS continue to operate as exceptions to the regulatory framework rather than being governed by it. This has limited the number of UAS operations in the national airspace, and that limitation has, in turn, contributed to the lack of operational data on UAS in domestic operations previously discussed. One industry forecast noted that growth in the non-military UAS market is unlikely until regulations allow for the routine operation of UAS. Without specific and permanent regulations for safe operation of UAS, federal stakeholders, including DOD, continue to face challenges. The lack of final regulations could hinder the acceleration of safe and routine integration of UAS into the national airspace.

Given the remaining obstacles to UAS integration, we stated in 2008 that Congress should consider creating an overarching body within FAA to coordinate federal, academic, and private-sector efforts in meeting the safety challenges of allowing routine access to the national airspace system. While it has not created this overarching body, FAA’s Joint Planning and Development Office has taken on a similar role. In addition, Congress set forth requirements for FAA in its February 2012 reauthorization to facilitate UAS integration. Additionally, we made two recommendations to FAA related to its planning and data analysis efforts to facilitate the process of allowing UAS routine access to the national airspace, which FAA has implemented.

Title 14, Code of Federal Regulations (14 CFR).

Role of the Department of Homeland Security in Domestic UAS Use

DHS is one of several partner agencies of FAA’s Joint Planning and Development Office (JPDO) working to safely integrate UAS into the national airspace. TSA has the authority to regulate the security of all transportation modes, including non-military UAS, and according to TSA officials, its aviation security efforts include monitoring reports on potential security threats regarding the use of UAS. While UAS operations in the national airspace are limited and take place under closely controlled conditions, this could change if UAS have routine access to the national airspace system. Further, DHS owns and uses UAS.

Security is a significant issue that could be exacerbated with an increase in the number of UAS, and could impede UAS use even after all other obstacles have been addressed. In 2004, TSA issued an advisory in which it stated that there was no credible evidence to suggest that terrorist organizations plan to use remote controlled aircraft or UAS in the United States. However, the TSA advisory also provided that the federal government remains concerned that UAS could be modified and used to attack key assets and infrastructure in the United States. TSA advised individuals to report any suspicious activities to local law enforcement and the TSA General Aviation Hotline. Security requirements have yet to be developed for UAS ground control stations—the UAS equivalent of the cockpit. Legislation introduced in the 112th Congress would prohibit the use of UAS as weapons while operating in the national airspace.

In our 2008 report, we recommended that the Secretary of Homeland Security direct the Administrator of TSA to examine the security implications of future, non-military UAS operations in the national airspace and take any actions deemed appropriate. TSA agreed that consideration and examination of new aviation technologies and operations is critical to ensuring the continued security of the national airspace. According to TSA officials, TSA continues to work with the FAA and other federal agencies concerning airspace security by implementing security procedures in an attempt to protect the National Airspace System. Examples of this collaboration include the coordinated efforts to allow access to temporary flight restricted airspace such as those put in place for Presidential travel and DHS Security Events. However, to date, neither DHS nor TSA has taken any actions to implement our 2008 recommendation. According to TSA officials, TSA believes its current practices are sufficient and no additional actions have been needed since we issued our recommendation.

DHS is also an owner and user of UAS. Since 2005, CBP has flown UAS for border security missions. FAA granted DHS authority to operate UAS to support its national security mission along the United States northern and southern land borders, among other areas. Recently, DHS officials told us that DHS has also flown UAS over the Caribbean to search for narcotics-carrying submarines and speedboats. According to DHS officials, CBP owns ten UAS that it operates in conjunction with other agencies for various missions. As of May 2012, CBP has flown missions to support six federal and state agencies along with several DHS agencies. These missions have included providing the National Oceanic and Atmospheric Administration with videos of damaged dams and bridges where flooding occurred or was threatened, and providing surveillance for DHS’s Immigration and Customs Enforcement over a suspected smuggler’s tunnel. DHS, DOD, and NASA, are working with FAA to identify and evaluate options to increase UAS access in the national airspace. DHS officials reported that if funding was available, they plan to expand their fleet to 24 total UAS that would be operational by fiscal year 2016, including 11 on the southwest border.

The DHS Inspector General reviewed CBP’s actions to establish its UAS program, the purpose of which is to provide reconnaissance, surveillance, targeting, and acquisition capabilities across all CBP areas of responsibility. The Inspector General assessed whether CBP has established an adequate operation plan to define, prioritize, and execute its unmanned aircraft mission. The Inspector General’s May 2012 report found that CBP had not achieved its scheduled or desired level of flight hours for its UAS. It estimated that CBP used its UAS less than 40 percent of the time it would have expected.

Preliminary Observations on Emerging UAS Issues

Our ongoing work has identified several UAS issues that, although not new, are emerging as areas of further consideration in light of the efforts towards safe and routine access to the national airspace. These include concerns about 1) privacy as it relates to the collection and use of surveillance data, 2) the use of model aircraft, which are aircraft flown for hobby or recreation, and 3) the jamming and spoofing of the Global Positioning System (GPS).

Privacy concerns over collection and use of surveillance data.

Following the enactment of the UAS provisions of the 2012 FAA reauthorization act, members of Congress, a civil liberties organization, and others have expressed concern that the increased use of UAS for surveillance and other purposes in the national airspace has potential privacy implications. Concerns include the potential for increased amounts of government surveillance using technologies placed on UAS as well as the collection and use of such data. Surveillance by federal agencies using UAS must take into account associated constitutional Fourth Amendment protections against unreasonable searches and seizures. In addition, at the individual agency level, there are multiple federal laws designed to provide protections for personal information used by federal agencies. While the 2012 FAA reauthorization act contains provisions designed to accelerate the safe integration of UAS into the national airspace, proposed legislation in the 112th session of Congress, seeks to limit or serve as a check on uses of UAS by, for example, limiting the ability of the federal government to use UAS to gather information pertaining to criminal conduct without a warrant.

Currently, no federal agency has specific statutory responsibility to regulate privacy matters relating to UAS. UAS stakeholders disagreed as to whether the regulation of UAS privacy related issues should be centralized within one federal agency, or if centralized, which agency would be best positioned to handle such a responsibility. Some stakeholders have suggested that FAA or another federal agency should develop regulations for the types of allowable uses of UAS to specifically protect the privacy of individuals as well as rules for the conditions and types of data that small UAS can collect. Furthermore, stakeholders with whom we spoke said that developing guidelines for technology use on UAS ahead of widespread adoption by law enforcement entities may preclude abuses of the technology and a negative public perception of UAS. Representatives from one civil liberties organization told us that since FAA has responsibility to regulate the national airspace, it could be positioned to handle responsibility for incorporating rules that govern UAS use and data collection. Some stakeholders have suggested that the FAA has the opportunity and responsibility to incorporate such privacy issues into the small UAS rule that is currently underway and in future rulemaking procedures. However, FAA officials have said that regulating these sensors is outside the FAA’s mission, which is primarily focused on aviation safety, and has proposed language in its small UAS Notice of Proposed Rulemaking to clarify this.

Model aircraft. According to an FAA official with whom we spoke and other stakeholders, another concern related to UAS is the oversight of the operation of model aircraft—aircraft flown for hobby or recreation—capable of sustained flight in the atmosphere and a number of other characteristics. Owners of model aircraft do not require a COA to operate their aircraft. Furthermore, as part of its 2012 reauthorization act, FAA is prohibited from developing any rule or regulation for model aircraft under a specified set of conditions.

However, the 2012 reauthorization act also specifies that nothing in the act’s model aircraft provisions shall be construed to limit FAA’s authority to take enforcement action against the operator of a model aircraft who endangers the safety of the national airspace system.

The Federal Bureau of Investigation report of the arrest and criminal prosecution of a man plotting to use a large remote-controlled model aircraft filled with plastic explosives to attack the Pentagon and U.S. Capitol in September 2011 has highlighted the potential for model aircraft to be used for non-approved or unintended purposes.

The Academy of Model Aeronautics, which promotes the development of model aviation as a recognized sport and represents a membership of over 150,000, published several documents to guide model aircraft users on safety, model aircraft size and speed, and use. For example, the Academy’s National Model Aircraft Safety Code specifies that model aircraft will not be flown in a careless or reckless manner and will not carry pyrotechnic devices that explode or burn, or any device that propels a projectile or drops any object that creates a hazard to persons or property (with some exceptions). Aeronautics also provides guidance on “sense and avoid” to its members, such as a ceiling of 400 feet above ground of aircraft weighing 55 pounds or less. However, apart from FAA’s voluntary safety standards for model aircraft operators, FAA has no regulations relating to model aircraft. Currently, FAA does not require a license for any model aircraft operators, but according to FAA, the small UAS Notice of Proposed Rule Making, under development and expected to be published late 2012, may contain a provision that requires certain model aircraft to be registered.

GPS jamming and spoofing.

The Academy of Model Aeronautics National Model Aircraft Safety Code allows members to fly devices that burn producing smoke and are securely attached to the model aircraft and use rocket motors if they remain attached to the model during flight. Model rockets may be flown but not launched from a model aircraft.

GPS spoofing is when counterfeit GPS signals are generated for the purpose of manipulating a target receiver’s reported position and time. Todd E. Humphreys, Detection Strategy for Cryptographic GNSS Anti-Spoofing, IEEE Transactions on Aerospace and Electronics Systems (August 2011). cost devices that jam GPS signals are prevalent. According to one industry expert, GPS jamming would become a larger problem if GPS is the only method for navigating a UAS. This problem can be mitigated by having a second or redundant navigation system onboard the UAS that is not reliant on GPS. In addition, a number of federal UAS stakeholders we interviewed stated that GPS jamming is not an issue for the larger, military-type UAS, as they have an encrypted communications link on the aircraft. A stakeholder noted that GPS jamming can be mitigated for small UAS by encrypting its communications, but the costs associated with encryption may make it infeasible. Recently, researchers at the University of Texas demonstrated that the GPS signal controlling a small UAS could be spoofed using a portable software radio. The research team found that it was straightforward to mount an intermediate-level spoofing attack but difficult and expensive to mount a more sophisticated attack.

The emerging issues we identified not only may exist as part of efforts to safely and routinely integrate UAS into the national airspace, but may also persist once integration has occurred. Thus, these issues may warrant further examination both presently and in the future.

Chairman McCaul, Ranking Member Keating, and Members of the Subcommittee, this concludes my prepared statement. We plan to report more fully this fall on these same issues, including the status of efforts to address obstacles to the safe and routine integration of UAS into the national airspace. I would be pleased to answer any questions at this time.

GAO Contact and Staff Acknowledgements

For further information on this testimony, please contact Gerald L. Dillingham, Ph.D., at (202) 512-2834 or dillinghamg@gao.gov. In addition, contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this statement. Individuals making key contributions to this testimony include Maria Edelstein, Assistant Director; Amy Abramowitz; Erin Cohen; John de Ferrari; Colin Fallon; Rebecca Gambler; Geoffrey Hamilton; David Hooper; Daniel Hoy; Joe Kirschbaum; Brian Lepore; SaraAnn Moessbauer; Faye Morrison; Sharon Pickup; Tina Won Sherman; and Matthew Ullengren.

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