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

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: UAS aircraft do not carry a human operator on board, but instead operate on pre-programmed routes or by following commands from pilot-operated ground stations. An aircraft is considered to be a small UAS if it is 55 pounds or less, while a large UAS is anything greater. Current domestic uses of UAS are limited and include law enforcement, monitoring or fighting forest fires, border security, weather research, and scientific data collection by the federal government. FAA authorizes military and non-military UAS operations on a limited basis after conducting a case-by-case safety review. Several other federal agencies also have a role or interest in UAS, including DHS. In 2008, GAO reported that safe and routine access to the national airspace system poses several obstacles.
This testimony discusses 1) obstacles identified in GAOs previous report on the safe and routine integration of UAS into the national airspace, 2) DHSs role in the domestic use of these systems, and 3) preliminary observations on emerging issues from GAOs ongoing work.
This testimony is based on a 2008 GAO report and ongoing work, and is focused on issues related to non-military UAS. In ongoing work, GAO analyzed FAAs efforts to integrate UAS into the national airspace, the role of other federal agencies in achieving safe and routine integration, and other emerging issues; reviewed FAA and other federal agency efforts and documents; and conducted selected interviews with officials from FAA and other federal, industry, and academic stakeholders.
section_title: What GAO Found
paragraphs: GAO earlier reported that unmanned aircraft systems (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. These include 1) the inability for UAS to detect, sense, and avoid other aircraft and airborne objects in a manner similar to see and avoid by a pilot in a manned aircraft; 2) vulnerabilities in the command and control of UAS operations; 3) the lack of technological and operational standards needed to guide the safe and consistent performance of UAS; and 4) the lack of final regulations to accelerate the safe integration of UAS into the national airspace. GAO stated in 2008 that Congress should consider creating an overarching body within the Federal Aviation Administration (FAA) to address obstacles for routine access. FAAs Joint Planning and Development Office (JPDO) has taken on a similar role. FAA has implemented GAOs two recommendations related to its planning and data analysis efforts to facilitate integration.
The Department of Homeland Security (DHS) is one of several partner agencies of JPDO working to safely integrate UAS into the national airspace. Since 2005, FAA has granted DHS authority to operate UAS to support its national security mission in areas such as the U.S. northern and southern land borders. DHSs Transportation Security Administration (TSA) has the authority to regulate security of all modes of transportation, 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. Security considerations could be exacerbated with routine UAS access. TSA has not taken any actions to implement GAOs 2008 recommendation that it examine the security implications of future, non-military UAS.
GAOs ongoing work has identified several UAS issues that, although not new, are emerging as areas of further consideration in light of greater access to the national airspace. These include concerns about privacy relating to the collection and use of surveillance data. Currently, no federal agency has specific statutory responsibility to regulate privacy matters relating to UAS. Another emerging issue is the use of model aircraft (aircraft flown for hobby or recreation) in the national airspace. FAA is generally prohibited from developing any rule or regulation for model aircraft. The Federal Bureau of Investigation report of a plot to use a 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 unintended purposes. An additional emerging issue is interruption of the command and control of UAS operations through the jamming and spoofing of the Global Positioning System between the UAS and ground control station. GAO plans to report more fully this fall on these issues, including the status of efforts to address obstacles to the safe and routine integration of UAS into the national airspace.

section_title: Letter
paragraphs: I appreciate the opportunity to testify before you today on obstacles to  unmanned aircraft systems (UAS) safe and routine operations in the  national airspace, the role that the Department of Homeland Security  (DHS) has in UAS operations, and emerging UAS issues. Many  stakeholders have exhibited increased interest in UAS for border security  and disaster assistance, among other uses. Additionally, as combat  operations in Afghanistan decrease, all of the United States military  services expect to conduct more UAS training flights across the  contiguous United States.
UAS aircraft do not carry a human operator on board, but instead operate  on pre-programmed routes or by following commands from pilot-operated  ground stations. These aircraft are also referred to as “unmanned aerial  vehicles,” “remotely piloted aircraft,” “unmanned aircraft,” or “drones.” The  term “unmanned aircraft system” is used to recognize that a UAS includes  not only the airframe, but also associated elements such as a ground  station and the communications links. UAS are typically described in  terms of weight, endurance, purpose of use, and altitude of operation.  Most UAS are considered small, weighing less than 55 pounds; some of  which fly less than 400 feet above the ground. According to an industry  association, small UAS are expected to comprise the majority of UAS that  will operate in the national airspace.
The Federal Aviation Administration (FAA) authorizes military and non- military (academic institutions; federal, state, and local governments  including law enforcement entities; and private sector entities) UAS  operations on a limited basis after conducting a case-by-case safety  review. Only federal, state, and local government agencies can apply for  a Certificate of Waiver or Authorization (COA); private sector entities must  apply for special airworthiness certificates in the experimental category.
Between January 1, 2012 and July 17, 2012, FAA had issued 201 COAs  to 106 federal, state, and local government entities across the United  States, including law enforcement entities as well as academic  institutions. Additionally, FAA had issued 8 special airworthiness  certifications for experimental use to four UAS manufacturers. Presently,  under COA or special airworthiness certification, UAS operations are  permitted for specific times, locations, and operations. Thus it is not  uncommon for an entity to receive multiple COAs for various missions.  Over the years, concerns have been expressed by the Congress and  other stakeholders that sufficient progress has not been made to integrate  UAS into the national airspace system. In 2008, GAO reported that safe  and routine access to the national airspace system poses several  obstacles. We also stated 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. 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. We also recommended that DHS assess the security  implications of routine access. FAA is working toward implementing the  requirements set forth by its February 2012 reauthorization to accelerate  UAS integration.
Senior executives from these four federal agencies represent the UAS ExCom, whose  mission is to enable increased and ultimately routine access of federal UAS engaged in  non-military aircraft operations into the national airspace to support these agencies’  operational, training, development, and research requirements. intelligence, surveillance, reconnaissance, and combat missions.many of DOD’s UAS operations currently take place outside of the United  States, the military services require access to the national airspace to  conduct UAS training. DOD has also assisted DHS in border security  missions, including two missions since 2006 where the National Guard  provided support in four southwestern border states. NASA uses UAS  primarily for research purposes, such as the Predator B for wildfire  mapping and investigations as well as an expected arctic mission next  year on surface sea ice.
GAO, Unmanned Aircraft Systems: Federal Actions Needed to Ensure Safety and  Expand Their Potential Uses within the National Airspace System, GAO-08-511  (Washington, D.C.: May 15, 2008). provides a reasonable basis for our findings and conclusions based on  our audit objectives.
subsections: section_title: Background
paragraphs: 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.
section_title: Obstacles to Safe and Routine Integration of UAS
paragraphs: 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).
section_title: Role of the Department of Homeland Security in Domestic UAS Use
paragraphs: 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.
section_title: Preliminary Observations on Emerging UAS Issues
paragraphs: 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.
section_title: GAO Contact and Staff Acknowledgements
paragraphs: 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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