Unmanned aerial vehicle An unmanned aerial vehicle ( UAV ) , also known as a drone , is an aircraft without a human pilot on board . Its flight is controlled either autonomously by computers in the vehicle or under the remote control of a pilot on the ground or in another vehicle . The typical launch and recovery method or " Pop and Stop " of an unmanned aircraft is by the function of an automatic system or an external operator on the ground . There are a wide variety of UAV shapes , sizes , configurations , and characteristics . Historically , UAVs were simple remotely piloted aircraft , but autonomous control is increasingly being employed . They are usually deployed for military and special operation applications , but also used in a small but growing number of civil applications , such as policing and firefighting , and nonmilitary security work , such as surveillance of pipelines . UAVs are often preferred for missions that are too " dull , dirty or dangerous " for manned aircraft . History . The earliest attempt at a powered unmanned aerial vehicle was A . M . Low ' s " Aerial Target " of 1916 . Nikola Tesla described a fleet of unmanned aerial combat vehicles in 1915 . A number of remote - controlled airplane advances followed during and after World War I , including the Hewitt - Sperry Automatic Airplane . The first scale RPV ( Remote Piloted Vehicle ) was developed by the film star and model airplane enthusiast Reginald Denny in 1935 . More were made in the technology rush during World War II ; these were used both to train antiaircraft gunners and to fly attack missions . Nazi Germany also produced and used various UAV aircraft during the course of WWII . Jet engines were applied after World War II in such types as the Teledyne Ryan Firebee I of 1951 , while companies like Beechcraft also got in the game with their Model 1001 for the United States Navy in 1955 . Nevertheless , they were little more than remote - controlled airplanes until the Vietnam Era . The birth of U . S . UAVs ( called RPVs at the time ) began in 1959 when United States Air Force ( USAF ) officers , concerned about losing pilots over hostile territory , began planning for the use of unmanned flights . This plan became intensified when Francis Gary Powers and his " secret " U - 2 were shot down over the Soviet Union in 1960 . Within days , the highly classified UAV program was launched under the code name of " Red Wagon " . The August 2 and August 4 , 1964 , clash in the Tonkin Gulf between naval units of the U . S . and North Vietnamese Navy initiated America ' s highly classified UAVs into their first combat missions of the Vietnam War . When the " Red Chinese " showed photographs of downed U . S . UAVs via " Wide World Photos " , the official U . S . response was " no comment . " There are two prominent UAV programs within the United States : that of the military and that of the Central Intelligence Agency ( CIA ) . The military ’ s UAV program is overt , meaning it is recognized by the public and therefore only operates where US troops are stationed . The CIA ’ s program is covert . Missions performed by the CIA ’ s UAV program do not always occur where US troops are stationed . The CIA ’ s UAV program was commissioned as a result of the September 11 terrorist attacks and the increasing emphasis on operations for intelligence gathering in 2004 . This clandestine program is primarily being used in Afghanistan , Pakistan , Yemen , and Somalia . UAVs collect intelligence in these countries by loitering around their target . The CIA ’ s first UAV program is called the Eagle Program . It was led by Duane Clarridge , the director of the Counterterrorism Center . This program constructed the CIA ’ s first using “ off the shelf technology , ” which included items such as garage door openers and model airplanes . Only on February 26 , 1973 , during testimony before the United States House Committee on Appropriations , the U . S . military officially confirmed that they had been utilizing UAVs in Southeast Asia ( Vietnam ) . Over 5 , 000 U . S . airmen had been killed and over 1 , 000 more were either missing in action ( MIA ) or captured ( prisoners of war / POW ) . The USAF 100th Strategic Reconnaissance Wing had flown approximately 3 , 435 UAV missions during the war at a cost of about 554 UAVs lost to all causes . In the words of USAF General George S . Brown , Commander , Air Force Systems Command , in 1972 , " The only reason we need ( UAVs ) is that we don ' t want to needlessly expend the man in the cockpit . " Later that same year , General John C . Meyer , Commander in Chief , Strategic Air Command , stated , " we let the drone do the high - risk flying . . . the loss rate is high , but we are willing to risk more of them . . . " they save lives ! " During the 1973 Yom Kippur War , Soviet - supplied surface - to - air missile batteries in Egypt and Syria caused heavy damage to Israeli fighter jet s . As a result , Israel developed the first modern UAV . Israel pioneered the use of UAVs for real - time surveillance , electronic warfare , and decoys . The images and radar decoying provided by these UAVs helped Israel to completely neutralize the Syrian air defense s at the start of the 1982 Lebanon War , resulting in no pilots downed . The first time UAVs were used as proof - of - concept of super - agility post - stall controlled flight in combat flight simulations was with tailless , stealth technology - based , three - dimensional thrust vectoring flight control , jet steering UAVs in Israel in 1987 . With the maturing and miniaturization of applicable technologies as seen in the 1980s and 1990s , interest in UAVs grew within the higher echelons of the U . S . military . In the 1990s , the U . S . Department of Defense gave a contract to U . S . corporation AAI Corporation of Maryland along with Israeli company Mazlat . The U . S . Navy bought the AAI Pioneer UAV that was jointly developed by American AAI Corporation and Israeli Mazlat , and this type of UAV is still in use . Many of these Pioneer and newly developed U . S . UAVs were used in the 1991 Gulf War . UAVs were seen to offer the possibility of cheaper , more capable fighting machines that could be used without risk to aircrews . Initial generations were primarily surveillance aircraft , but some were armed , such as the General Atomics MQ - 1 Predator , which utilized AGM - 114 Hellfire air - to - ground missile s . An armed UAV is known as an unmanned combat air vehicle ( UCAV ) . As a tool for search and rescue , UAVs can help find humans lost in the wilderness , trapped in collapsed buildings , or adrift at sea . In February 2013 , it was reported that UAVs were used by at least 50 countries , several of which made their own : for example , Iran , Israel and China . The first UAV created was the Pioneer , which helps to identify artillery and boats ( Carafano & Gudgel , 2007 ) . Since its performance was so exemplary , they began to be used more and more , with new models constantly being introduced . As of 2008 , the United States Air Force employed 5 , 331 UAVs , which is twice its number of manned planes . Out of these , the Predator s are the most commendable . Unlike other UAVs , the Predator was armed with Hellfire missiles so that it can terminate the target that it locates ( Carafano & Gudgel , 2007 ) . This was done after Predators sighted Osama Bin Laden multiple times but could not do anything about it other than send back images . In addition , the Predator is capable of orchestrating attacks by pointing lasers at the targets ( Singer , 2009b ) . This is important , as it puts a robot in a position to set off an attack . Their overall success is apparent because from June 2005 to June 2006 alone , Predators carried out 2 , 073 missions and participated in 242 separate raids ( Singer , 2009a ) . In contrast to the Predator , which is remotely piloted via satellites by pilots located 7 , 500 miles away , the Global Hawk operates virtually autonomously . The user merely hits the button for ‘ take off ’ and for ‘ land ’ , while the UAV gets directions via GPS and reports back with a live feed . Global Hawks have the capability to fly from San Francisco and map out the entire state of Maine before having to return . In addition , some UAVs have become so small that they can be launched from one ’ s hand and maneuvered through the street . These UAVs , known as Raven s , are especially useful in urban areas , such as Iraq , in order to discover insurgents and potential ambushes the next block up ( Carafano & Gudgel , 2007 ) . UAVs are especially useful because they can fly for days at a time . According to Carafano & Gudgel , insurgents are loathe to stay in the open for more than a few minutes at a time for fear of UAVs locating them ( 2007 ) . FAA designation . In the United States , the United States Navy and , shortly after , the Federal Aviation Administration have adopted the name " unmanned aircraft " ( UA ) to describe aircraft systems without a flight crew on board . More common names include " UAV " , " drone " , " remotely piloted vehicle " ( " RPV " ) , " remotely piloted aircraft " ( " RPA " ) , and " remotely operated aircraft " ( " ROA " ) . These " limited - size " ( as defined by the FAI ) unmanned aircraft flown in the USA ' s National Airspace System , flown solely for recreation and sport purposes , such as models , are generally flown under the voluntary safety standards of the Academy of Model Aeronautics , the United States ' national aeromodeling organization . To operate a UA for non - recreational purposes in the United States , users must obtain a " Certificate of Authorization " ( COA ) to operate in national airspace . At the moment , COAs require a public entity as a sponsor . For example , when BP needed to observe oil spills , they operated the Aeryon Scout UAVs under a COA granted to the University of Alaska Fairbanks . COAs have been granted for both land and shipborne operations . As of August 2013 , commercial unmanned aerial system ( UAS ) licenses were granted on a case - by - case basis , subject to approval by the Federal Aviation Administration ( FAA ) . A Congressional mandate to integrate UASs into U . S . airspace protocols is forecast to grant FAA licenses more broadly as early as 2015 , the agency expecting that five years after it unveils a regulatory framework for UASs weighing 55 pounds or less , there will be 7 , 500 such devices in the air . The term unmanned aircraft system ( UAS ) emphasizes the importance of other elements beyond an aircraft itself . A typical UAS consists of the following : For example , the RQ - 7 Shadow UAS consists of four UAs , two GCSs , one portable GCS , one Launcher , two Ground Data Terminals ( GDTs ) , one portable GDT , and one Remote Video Terminal . Certain military units are also fielded with a maintenance support vehicle . Because of this systemic approach , unmanned aircraft systems have not been included in the United States Munitions List Category VIII – Aircraft and Associated Equipment . Vice versa , the “ Unmanned Aerial Vehicle Systems ” are clearly mentioned at paragraph 121 - 16 Missile Technology Control Regime Annex of the United States Munitions List . More precisely , the Missile Technology Control Regime Annex levels rocket and unmanned aerial vehicle systems together . The term UAS was since adopted by the United States Department of Defense ( DOD ) and the British Civil Aviation Authority ( CAA ) . The term used previously for unmanned aircraft system was unmanned - aircraft vehicle system ( UAVS ) . Classification . UAVs typically fall into one of six functional categories ( although multi - role airframe platforms are becoming more prevalent ) : They can also be categorised in terms of range / altitude and the following has been advanced as relevant at such industry events as ParcAberporth Unmanned Systems forum : The United States military employs a tier system for categorizing its UAVs . Classifications by the United States military . The modern concept of U . S . military UAVs is to have the various aircraft systems work together in support of personnel on the ground . The integration scheme is described in terms of a " Tier " system and is used by military planners to designate the various individual aircraft elements in an overall usage plan for integrated operations . The Tiers do not refer to specific models of aircraft but rather roles for which various models and their manufacturers competed . The U . S . Air Force and the U . S . Marine Corps each has its own tier system , and the two systems are themselves not integrated . Unmanned aircraft system . An unmanned aircraft system ( UAS ) includes ground stations and other elements besides the actual aircraft . The term was first officially used by the FAA in early 2005 and subsequently adopted by DoD that same year in their Unmanned Aircraft System Roadmap 2005 – 2030 . Many people have mistakenly used the term Unmanned " Aerial " System or Unmanned " Air Vehicle " System , as these designations were in provisional use at one time or another . The inclusion of the term aircraft emphasizes that regardless of the location of the pilot and flightcrew , the operations must comply with the same regulations and procedures as do those aircraft with the pilot and flightcrew on board . The official acronym " UAS " is also used by the International Civil Aviation Organization ( ICAO ) and other government aviation regulatory organizations . The military role of unmanned aircraft systems is growing at unprecedented rates . In 2005 , tactical - and theater - level unmanned aircraft alone had flown over 100 , 000 flight hours in support of Operation Enduring Freedom and Operation Iraqi Freedom , in which they are organized under Task Force Liberty in Afghanistan and Task Force ODIN in Iraq . Rapid advances in technology are enabling more and more capability to be placed on smaller airframes , which is spurring a large increase in the number of Small Unmanned Aircraft Systems ( SUAS ) being deployed on the battlefield . The use of SUAS in combat is so new that no formal DoD wide reporting procedures have been established to track SUAS flight hours . As the capabilities grow for all types of UAS , nations continue to subsidize their research and development , leading to further advances and enabling them to perform a multitude of missions . UAS no longer only perform intelligence , surveillance , and reconnaissance missions , although this still remains their predominant type . Their roles have expanded to areas including electronic attack , strike missions , suppression and / or destruction of enemy air defense , network node or communications relay , combat search and rescue , and derivations of these themes . These UAS range in cost from a few thousand dollars to tens of millions of dollars , with aircraft ranging from less than one pound to over 40 , 000 pounds . When the Obama administration announced in December 2009 the deployment of 30 , 000 new troops in Afghanistan , there was already an increase of attacks by unmanned Predator UAVs against Taliban and al - Qaeda militants in Afghanistan and Pakistan ' s tribal areas , of which one probably killed a key member of al - Qaeda . However , neither Osama bin Laden nor Ayman al - Zawahiri was the likely target , according to reports . According to a report of the New America Foundation , armed UAV strikes had dramatically increased under President Obama – even before his deployment decision . There were 43 such attacks between January and October 2009 . The report draws on what it deems to be " " credible " " local and national media stories about the attacks . This can be compared to a total of 34 in all of 2008 , which was President Bush ' s last full year in office . Between 2006 and 2009 , UAV - launched missiles allegedly had killed between 750 and 1 , 000 people in Pakistan , according to the report . Of these , about 20 people were said to be leaders of al - Qaeda , Taliban , and associated groups . Overall , 66 % to 68 % of the people killed were militants , and 31 % to 33 % were civilians . U . S . officials disputed the percentage for civilians . The U . S . Air Force has recently begun referring at least to larger UAS like Predator , Reaper , and Global Hawk as Remotely Piloted Aircraft ( RPA ) to highlight the fact that these systems are always controlled by a human operator at some location . However , artificial intelligence is advancing to the point where the aircraft are easily capable of taking off , landing , and flying themselves . Then they simply have to be instructed as to their mission . The military distinguishes between " man " in " the loop " ( piloted ) and " man " on " the loop " ( supervised ) systems , with " fully autonomous " ( issued orders ) growing organically from the second into a third category . A . I . systems have been capable of making decisions and planning sequences of actions for decades ; as of 2013 , few fully autonomous systems have been constructed , but this is more a matter of convenience and technical implementation than of any fundamental barrier . To distinguish UAVs from " missiles " , a UAV is defined as a " powered , aerial vehicle that does not carry a human operator , uses aerodynamic forces to provide vehicle lift , can fly autonomously or be piloted remotely , can be expendable or recoverable , and can carry a lethal or nonlethal payload " . Therefore , cruise missile s are not considered UAVs because , like many other guided missiles , the vehicle itself is a weapon that is not reused , even though it is also unmanned and in some cases remotely guided . Uses . Beyond the military applications of UAVs with which " drones " became most associated , numerous civil aviation uses have been developed , including aerial surveying of crops , acrobatic aerial footage in filmmaking , search and rescue operations , inspecting power lines and pipelines , and counting wildlife , with manufacturers rebranding the technology as " unmanned aerial systems " ( UASs ) in preference over " drones . " Remote sensing . UAV remote sensing functions include electromagnetic spectrum sensors , gamma ray sensors , biological sensors , and chemical sensors . A UAV ' s electromagnetic sensor s typically include visual spectrum , infrared , or near infrared cameras as well as radar systems . Other electromagnetic wave detectors such as microwave and ultraviolet spectrum sensors may also be used but are uncommon . Biological sensors are sensors capable of detecting the airborne presence of various microorganisms and other biological factors . Chemical sensors use laser spectroscopy to analyze the concentrations of each element in the air . Commercial aerial surveillance . Aerial surveillance of large areas is made possible with low cost UAV systems . Surveillance applications include livestock monitoring , wildfire mapping , pipeline security , home security , road patrol , and anti - piracy . The trend for the use of UAV technology in commercial aerial surveillance is expanding rapidly with increased development of automated object detection approaches . Domestic policing . UAVs are increasingly used for domestic police work in Canada and the United States : a dozen US police forces had applied for UAV permits by March 2013 . Texas politician and commentator Jim Hightower has warned about potential privacy abuses from aerial surveillance . In February 2013 , Seattle Mayor Michael McGinn responded to protests by scrapping the Seattle Police Department ’ s plan to deploy UAVs . Oil , gas and mineral exploration and production . UAVs can be used to perform geophysical surveys , in particular geomagnetic surveys where the processed measurements of the Earth ' s differential magnetic field strength are used to calculate the nature of the underlying magnetic rock structure . A knowledge of the underlying rock structure helps trained geophysicists to predict the location of mineral deposits . The production side of oil and gas exploration and production entails the monitoring of the integrity of oil and gas pipelines and related installations . For above - ground pipelines , this monitoring activity could be performed using digital cameras mounted on one or more UAVs . The InView Unmanned Aircraft System is an example of a UAV developed for use in oil , gas , and mineral exploration and production activities . Transport . UAVs can transport goods using various means based on the configuration of the UAV itself . Most payloads are stored in an internal payload bay somewhere in the airframe . For many helicopter configurations , external payloads can be tethered to the bottom of the airframe . With fixed - wing UAVs , payloads can also be attached to the airframe , but aerodynamics of the aircraft with the payload must be assessed . For such situations , payloads are often enclosed in aerodynamic pods for transport . Scientific research . Unmanned aircraft are especially useful in penetrating areas that may be too dangerous for manned aircraft . The National Oceanic and Atmospheric Administration ( NOAA ) began utilizing the Aerosonde unmanned aircraft system in 2006 as a hurricane hunter . AAI Corporation subsidiary Aerosonde Pty Ltd . of Victoria , Australia , designs and manufactures the 35 - pound system , which can fly into a hurricane and communicate near - real - time data directly to the National Hurricane Center in Florida . Beyond the standard barometric pressure and temperature data typically culled from manned hurricane hunters , the Aerosonde system provides measurements far closer to the water ’ s surface than previously captured . Further applications for unmanned aircraft can be explored once solutions have been developed for their accommodation within national airspace , an issue currently under discussion by the Federal Aviation Administration . UAVSI , the UK manufacturer , also produces a variant of their Vigilant light UAS ( 20 kg ) designed specifically for scientific research in severe climates , such as the Antarctic . There have also been experiments with using UAVs as a construction and artwork tool at locations such as the ETH Zurich . Armed attacks . MQ - 1 Predator UAVs armed with Hellfire missiles are increasingly used by the U . S . as platforms for hitting ground targets . Armed Predators were first used in late 2001 from bases in Pakistan and Uzbekistan , mostly aimed at assassinating high profile individuals ( terrorist leaders , etc . ) inside Afghanistan . Since then , there have been many reported cases of such attacks taking place in Afghanistan , Pakistan , Yemen , and Somalia . The advantage of using an unmanned vehicle rather than a manned aircraft in such cases is to avoid a diplomatic embarrassment should the aircraft be shot down and the pilots captured , since the bombings take place in countries deemed friendly and without the official permission of those countries . A Predator based in a neighboring Arab country was used to kill suspected al - Qaeda terrorists in Yemen on November 3 , 2002 . This marked the first use of an armed Predator as an attack aircraft outside of a theater of war such as Afghanistan . The U . S . has claimed that the Predator strikes killed at least nine senior al - Qaeda leaders and dozens of lower - ranking operatives , depleting its operational tier in what U . S . officials described as the most serious disruption of al - Qaeda since 2001 . It was claimed that the Predator strikes took such a toll on al - Qaeda that militants began turning violently on one another out of confusion and distrust . A senior U . S . counter - terrorism official said : " They have started hunting down people who they think are responsible " for security breaches . " People are showing up dead , or disappearing . " By October 2009 , the CIA claimed to have killed more than half of the 20 most wanted al - Qaeda terrorist suspects in targeted killings using UAVs . By May 2010 , counter - terrorism officials said that UAV strikes in the Pakistani tribal areas had killed more than 500 militants since 2008 and no more than 30 ( 5 % ) nearby civilians — mainly family members who lived and traveled with the targets . UAVs linger overhead after a strike , in some cases for hours , to enable the CIA to count the bodies and attempt to determine which , if any , are civilians . A Pakistani intelligence officer gave a higher estimate of civilian casualties , saying 20 % of total deaths were civilians or non - combatants . In February 2013 , U . S . Senator Lindsey Graham stated that 4 , 756 people have been killed by U . S . UAVs . CIA officials became concerned in 2008 that targets in Pakistan were being tipped off to pending U . S . UAV strikes by Pakistani intelligence when the U . S . requested Pakistani permission prior to launching UAV - based attacks . The Bush administration therefore decided in August 2008 to abandon the practice of obtaining Pakistani government permission before launching missiles from UAVs , and in the next six months the CIA carried out at least 38 Predator strikes in northwest Pakistan , compared with 10 in 2006 and 2007 combined . In 2012 , the USAF trained more UAV pilots than ordinary jet fighter pilots for the first time . One issue with using armed drones to attack human targets is the size of the bombs being used and the relative lack of discrimination of the Hellfire , which was designed to eliminate tanks and attack bunkers . Smaller weapons such as the Raytheon Griffin and Small Tactical Munition are being developed as a less indiscriminate alternative , and development is underway on the still smaller US Navy - developed Spike missile . The payload - limited Predator A can also be armed with six Griffin missiles , as opposed to only two of the much - heavier Hellfires . Civilian casualties . Questions have been raised about the accuracy of UAV - based missile strikes . In March 2009 , " The Guardian " reported allegations that Israeli UAVs armed with missiles killed 48 Palestinian civilians in the Gaza Strip , including two small children in a field and a group of women and girls in an otherwise empty street . In June , Human Rights Watch investigated six UAV attacks that were reported to have resulted in civilian casualties and alleged that Israeli forces either failed to take all feasible precautions to verify that the targets were combatants or failed to distinguish between combatants and civilians . In July 2009 , Brookings Institution released a report stating that in the United States - led drone attacks in Pakistan , ten civilians died for every militant killed . S . Azmat Hassan , a former ambassador of Pakistan , said in July 2009 that American UAV attacks were turning Pakistani opinion against the United States and that 35 or 40 such attacks only killed 8 or 9 top al - Qaeda operatives . Although it may never be known how many civilians have died as a result of U . S . UAV strikes in Pakistan , there are estimates of hundreds or thousands of innocent bystanders who have perished in such attacks . Pakistani authorities released statistics indicating that between January 1 , 2009 and December 31 , 2009 , U . S . RQ - 1 Predator and RQ - 9 Reaper UAV strikes have killed over 700 innocent civilians . The website PakistanBodyCount . Org ( by Zeeshan - ul - hassan Usmani , a Fulbright Scholar at the Florida Institute of Technology ) shows 1 , 065 civilian deaths between June 2004 and January 30 , 2010 and tallies 103 UAV strikes carried out by the United States . With the increase of UAV strikes , January 2010 proved to be a deadly month in Pakistan with 123 innocent civilians killed , according to a story in The International News . In addition , it has been reported that 160 children have died from UAV - launched attacks in Pakistan . Further , over 1 , 000 civilians have been injured . This evidence runs counter to the Obama administration ' s claim that " nearly for the past year there hasn ' t been a single collateral death " due to UAV - based attacks . According to the February 24 , 2010 policy analysis " The Year of the Drone " released by the New America Foundation , the civilian fatality rate since 2004 is approximately 32 % . The study reports that 114 reported UAV - based missile strikes in northwest Pakistan from 2004 to present killed between 830 and 1 , 210 individuals , around 550 to 850 of whom were militants . After more than 30 UAV - based strikes hit civilian homes in Afghanistan in 2012 , President Hamid Karzai demanded that such attacks end , but the practice continues in areas of Pakistan , Yemen , and Somalia that are not in war zones . Former U . S . President Jimmy Carter has criticized such use of UAVs : " We don ' t know how many hundreds of innocent civilians have been killed in these attacks . . . This would have been unthinkable in previous times . " Aerial target practice in training of human pilots . Since 1997 , the U . S . military has used more than 80 F - 4 Phantoms converted into robotic planes for use as aerial targets for combat training of human pilots . The F - 4s were supplemented in September 2013 with F - 16s as more realistically maneuverable targets . Search and rescue . UAVs will likely play an increased role in search and rescue in the United States . This was demonstrated by the use of UAVs during the 2008 hurricanes that struck Louisiana and Texas . Micro UAVs , such as the Aeryon Scout , have been used to perform Search and Rescue activities on a smaller scale , such as the search for missing persons . For example , Predators , operating between 18 , 000 – 29 , 000 feet above sea level , performed search and rescue and damage assessment . Payloads carried were an optical sensor , which is a daytime and infrared camera in particular , and a synthetic aperture radar ( SAR ) . The Predator ' s SAR is a sophisticated all - weather sensor capable of providing photographic - like images through clouds , rain or fog , and in daytime or nighttime conditions , all in real - time . A concept of coherent change detection in SAR images allows for exceptional search and rescue ability : photos taken before and after the storm hits are compared , and a computer highlights areas of damage . Conservation . In June 2012 , WWF announced it will begin using UAVs in Nepal to aid conservation efforts following a successful trial of two aircraft in Chitwan National Park , with ambitions to expand to other countries , such as Tanzania and Malaysia . The global wildlife organization plans to train ten personnel to use the UAVs , with operational use beginning in the fall . In August 2012 , UAVs were used by members of the Sea Shepherd Conservation Society in Namibia to document the annual seal cull . In March 2013 , the Times published a controversial story that UAV conservation nonprofit ShadowView , founded by former members of Sea Shepherd Conservation Society , had been working for several months with anti - hunting charity The League Against Cruel Sports to expose illegal fox hunting in the UK ; hunt supporters have argued that using UAVs to film hunting is an invasion of privacy . Maritime patrol . Japan is studying how to deal with the UAVs the PRC is starting to use to enforce their claims on unmanned islands . Forest fire detection . Another application of UAVs is the prevention and early detection of forest fires . The chief exponent of this type is the FT - ALTEA , developed by Flightech Systems . The possibility of constant flight , both day and night , makes the methods used until now ( helicopters , watchtowers , etc . ) become obsolete . Its payload consists of numerous cameras ( HD , thermal , hyperspectral , etc . ) and multiple sensors that provide real - time emergency services , including information about the location of the outbreak of fire as well as many factors ( wind speed , temperature , humidity , etc . ) that are helpful for fire crews to conduct fire suppression . Archaeology . In Peru archaeologists use drones to speed up survey work and protect sites from squatters , builders and miners . Small drones helped researchers produce three - dimensional models of Peruvian sites instead of the usual flat maps — and in days and weeks instead of months and years . Drones have replaced expensive and clumsy small planes , kites and helium balloons . Drones costing as little as£650 have proven useful . In 2013 drones have flown over at least six Peruvian archaeological sites , including the colonial Andean town Machu Llacta above sea level . The drones continue to have altitude problems in the Andes , leading to plans to make a drone blimp , employing open source software . Jeffrey Quilter , an archaeologist with Harvard University said , " You can go up three metres and photograph a room , 300 metres and photograph a site , or you can go up 3 , 000 metres and photograph the entire valley . " Future potential . In the future , UAVs may be able to perform a variety of unique tasks apart from what they are capable of today . Engineers are currently working to produce remotely piloted UAVs that are capable of air to air combat , aerial refueling , combat search and rescue with facial recognition , and resupply to agents on the ground . Design and development considerations . UAV design and production is a global activity with manufacturers all across the world . The United States and Israel were initial pioneers in this technology , and U . S . manufacturers had a market share of over 60 % in 2006 , with U . S . market share due to increase by 5 – 10 % through 2016 . Northrop Grumman and General Atomics are the dominant manufacturers in this industry on the strength of the Global Hawk and Predator / Mariner systems . The FAA Modernization and Reform Act of 2012 required selection of six test sites from 24 applicant states , to study UAS safety and certify commercial UASs for use in U . S . airspace . Some universities offer UAS research and training programs or academic degrees . According to the Stockholm International Peace Research Institute , Israeli companies were behind 41 % of all UAVs exported in 2001 - 2011 . The European market share represented 4 % of global revenue in 2006 . Development costs for American military UAVs , as with most military programs , have tended to overrun their initial estimates . This is mostly due to changes in requirements during development and a failure to leverage UAV development programs over multiple armed services . This has caused United States Navy UAV programs to increase in cost from 0 % to 5 % , while United States Air Force UAV programs have increased from 60 % to 284 % . Degree of autonomy . Early UAVs used during the Vietnam War captured video that was recorded to film or tape on the aircraft . These aircraft often flew either in a straight line or in preset circles collecting video until they ran out of fuel and landed . After landing , the film was recovered for analysis . Because of the simple , repetitive nature of these operations , the aircraft were often called " drones " . As new radio control systems became available , UAVs were often remote controlled , and the term " remotely piloted vehicle " came into vogue . Today ' s UAVs often combine remote control and computerized automation . More sophisticated versions may have built - in control and / or guidance systems to perform low - level human pilot duties , such as speed and flight - path stabilization , and simple scripted navigation functions , such as waypoint following . In news and other discussions , the term " drone " is still often mistakenly used to refer to these more sophisticated aircraft . From this perspective , most early UAVs were not autonomous at all . In fact , the field of air - vehicle autonomy is a recently emerging field , largely driven by the military to develop battle - ready technology . Compared to the manufacturing of UAV flight hardware , the market for autonomy technology is fairly immature and undeveloped . Autonomy technology that is important to UAV development falls under the following categories : Autonomy is commonly defined as the ability to make decisions without human intervention . To that end , the goal of autonomy is to teach machines to be " smart " and act more like humans . The keen observer may associate this with the developments in the field of artificial intelligence made popular in the 1980s and 1990s , such as expert system s , neural network s , machine learning , natural language processing , and vision . However , the mode of technological development in the field of autonomy has mostly followed a bottom - up approach , such as hierarchical control system s , and recent advances have been largely driven by the practitioners in the field of control science , not computer science . Similarly , autonomy has been and probably will continue to be considered an extension of the controls field . To some extent , the ultimate goal in the development of autonomy technology is to replace the human pilot . It remains to be seen whether future developments of autonomy technology , the perception of the technology , and , most importantly , the political climate surrounding the use of such technology will limit the development and utility of autonomy for UAV applications . Also as a result of this , synthetic vision for piloting has not caught on in the UAV arena as it did with manned aircraft . NASA utilized synthetic vision for test pilots on the HiMAT program in the early 1980s ( see photo ) , but the advent of more autonomous UAV autopilots greatly reduced the need for this technology . Interoperable UAV technologies became essential as systems proved their mettle in military operations , taking on tasks too challenging or dangerous for troops . NATO addressed the need for commonality through STANAG ( Standardization Agreement ) 4586 . According to a NATO press release , the agreement began the ratification process in 1992 . Its goal was to allow allied nations to easily share information obtained from unmanned aircraft through common ground control station technology . Aircraft that adhere to the STANAG 4586 protocol are equipped to translate information into standardized message formats ; likewise , information received from other compliant aircraft can be transferred into vehicle - specific messaging formats for seamless interoperability . Amendments have since been made to the original agreement based on expert feedback from the field and an industry panel known as the Custodian Support Team . Edition Two of STANAG 4586 is currently under review . There are many systems available today that are developed in accordance with STANAG 4586 , including products by industry leaders such as AAI Corporation , CDL Systems , and Raytheon , all three of which are members of the Custodian Support Team for this protocol . Endurance . Because UAVs are not burdened with the physiological limitations of human pilots , they can be designed for maximized on - station times . The maximum flight duration of unmanned aerial vehicles varies widely . Internal combustion engine aircraft endurance depends strongly on the percentage of fuel burned as a fraction of total weight ( the Breguet endurance equation ) and so is largely independent of aircraft size . Because of the small size , weight , very low vibration and high power to weight ratio , Wankel rotary engines are increasingly being used in UAV aircraft . The engine is approximately one third of the size and weight of a piston engine of equivalent power output , which offers significant advantages for UAV aircraft . Additionally : the engine rotors cannot seize , since rotor casings expand more than rotors ; the engine is not susceptible to shock - cooling during descent ; it does not require an enriched mixture for cooling at high power and having no reciprocating parts , there is less vulnerability to damage when the engines revolves higher than the designed maximum running operation . The attributes of the Wankel engine transpire into less fuel usage in UAVs giving greater range or a higher payload . Solar - electric UAVs hold potential for unlimited flight , a concept originally championed by the AstroFlight Sunrise in 1974 and the much later Aerovironment Helios Prototype , which was destroyed in a 2003 crash . Electric UAVs kept aloft indefinitely by laser power - beaming technology represent another proposed solution to the endurance challenge . This approach is advocated by Jordin Kare and Thomas Nugent . One of the major problems with UAVs is the lack of inflight refueling capability . In 2012 , the US Air Force was promoting research that should end in an inflight UAV refueling capability . A UAV - UAV simulated refuelling flight using two Global Hawk s was achieved in 2012 . One of the uses for a high endurance UAV would be to " stare " at the battlefield for a long period of time to produce a record of events that could then be played backwards to track where improvised explosive devices ( IEDs ) came from . Air Force Chief of Staff John P . Jumper started a program to create these persistent UAVs , but this was stopped once he was replaced . In 2007 , the Defense Advanced Research Projects Agency ( DARPA ) revealed a program to develop technology for a UAV with an endurance capability of over 5 years . The program , entitled VULTURE ( Very - high altitude , Ultra - endurance , Loitering Theater Unmanned Reconnaissance Element ) , entered Phase II on September 14 , 2010 , with a contract signed with Boeing for development of the SolarEagle flight demonstrator . Detect and avoid . The U . K . ' s Civil Aviation Authority ( CAA ) has stated that it will require non - military drones larger than 20 kg to be able to automatically sense other aircraft and steer to avoid them , a technology still missing in civilian UAVs as of 2012 . Hardening of the control stations . Given the increasing military use of cyber attacks against Microsoft software , the United States Armed Forces have moved towards Linux ground control software . Buddy attacks . The USAF said in 2012 that it will focus development of UAVs to be collaboratively networked with manned aircraft in " buddy attacks , " while continuing to be able to fly as standalone systems . Existing UAV systems . UAVs have been developed and deployed by many countries around the world . For a list of models by country , see : " List of unmanned aerial vehicles " . The use of unmanned aerial systems , however , is not limited to state powers : non - state actors can also build , buy and operate these combat vehicles . The export of UAVs or technology capable of carrying a 500 kg payload at least 300 km is restricted in many countries by the Missile Technology Control Regime . At the center of the American military ' s continued UAV research is the MQ - X , which builds upon the capabilities of the Reaper and Predator UAVs . As currently conceived , the MQ - X would be a stealthier and faster fighter - plane sized UAV capable of any number of missions : high - performance surveillance ; attack options , including retractable cannons and bomb or missile payloads ; and cargo capacity . China has exhibited some UAV designs , but its ability to operate them is limited by the lack of high endurance domestic engines , satellite infrastructure , and operational experience . Domestic aerial surveillance . Although UAVs are today most commonly associated with military actions , UAVs are increasingly used by civilian government agencies , businesses , and private individuals . In the United States , for example , government agencies use UAVs such as the RQ - 9 Reaper to patrol the nation ' s borders , scout property , and locate fugitives . One of the first authorized for domestic usage was the ShadowHawk UAV in service in Montgomery County , Texas , and is being used by their SWAT and emergency management offices . UAVs over Australia . Sydney Harbour Bridge collision . On 2 October 2013 a UAV collided with Sydney Harbour Bridge . The craft , which carried a camera , was found about 10pm near a southern pylon of the bridge . Although it was found the day before the International Navy Fleet Review , police believed there was no connection with the event . The Civil Aviation Safety Authority started an investigation and anti - terrorism officers were alerted , though police said they didn ' t believe it was suspicious and was for recreational use . A CASA spokesman said that they had been contacted by the New South Wales Police Force . He added that those operating remotely piloted aircraft should keep them at least 30m away from structures , buildings and people , to check with the local council where they could be used and that the airspace around the bridge was restricted for all aircraft , including small ones . UAVs over Belgium . In 2013 , The Flemish Research Institute for Nature and Forest and the Flanders Marine Institute planned to use a UAV with a camera and a detection system that automatically recognizes different types of vegetation , trees and individual plants in order to make regular assessments of the biodiversity of the Flemish terrain . Their previous system of using 25 civil servants to map the country was unsatisfactory and time - consuming . UAVs over Democratic Republic of Congo . In August 2013 , the Italian defence company Selex ES provided an unarmed surveillance drone to be deployed in the Democratic Republic of Congo to monitor movements of armed groups in the region and to protect the civilian population more effectively . UAVs over Germany . The Deutsche Bahn ( German national railways ) said in 2013 that it would test small surveillance UAVs with thermal cameras to prosecute vandals who spray graffiti on its property at night . Graffiti incidents cost the Deutsche Bahn $ 10 million per year to clean up . UAVs over Japan . T - Hawk and Global Hawk drones were used to gather information about the damaged Fukushima Number 1 nuclear plant and disaster - stricken areas of the Tōhoku region after the March 2011 tsunami . Anti - whaling activists used an Osprey UAV ( made by Kansas - based Hangar 18 ) in 2012 to monitor Japanese whaling ships in the Antarctic . UAVs over Nepal . In 2012 , the World Wildlife Fund supplied two FPV Raptor 1 . 6 UAVs to the Nepal National Parks . These UAVs were used to monitor rhinos tigers and elephants and deter poachers . The UAVs were equipped with time lapse cameras and could fly for 18 miles at 650 feet . UAVs over the Republic of Ireland . In 2012 Loitering Theatre group flew Parrot AR . Drone s near Áras an Uachtaráin , the Magazine Fort , a prison facility and offices of Google on Barrow Street and also Facebook . Footage filmed by the group was shown at an exhibit run by the Dublin Science Gallery . The Irish Aviation Authority stated that this was prohibited as Dublin city is classed as a restricted area . A separate group , called Tomorrows Thoughts Today , who had attended the same event were detained on their return to the UK at London Southend Airport under the Terrorism Act . They were released after a couple of hours questioning . Legal status . In May 2012 the Irish Aviation Authority published a document setting out safety requirements for any Unmanned Aerial System , regardless of mass . An appendix contained an application form to apply to operate a UAS . The only previous legislation had been the ' Irish Aviation Authority ( Rockets and Small Aircraft ) Order , 2000 ' . The IAA policy is that Unmanned Aerial Systems may not be flown without the operator receiving a specific Permission from the IAA . Where such a craft is to be used for commercial work , the operator must apply to the IAA for an Aerial Work Permission from the IAA . Flying UAS outside the direct , unaided line of sight of the operator is not allowed for safety reasons . It is not permitted to use vision - enhancing systems , such as First Person View . On 15 November 2012 the Irish Aviation Authority introduced a requirement that Remotely Piloted Aircraft needed to be registered to comply with Statutory Instrument 634 or 2005 ' Nationality and Registration of Aircraft ' Order . UAVs over South Africa . In December 2012 , the Kruger National Park started using a Seeker II UAV against rhino poachers . The UAV was loaned to the South African National Parks authority by its manufacturer , Denel Dynamics of South Africa . UAVs over the United Kingdom . In 2007 Merseyside Police was reported to be conducting tests with a UAV . Merseyside Police caught a car thief with a UAV in 2010 , but about a week later had to stop UAV operations as the craft was not licenced as new legislation required . A licence was granted by the Civil Aviation Authority . The UAS was lost during a training exercise in Aigburth , Liverpool , when crashing into the River Mersey . Merseyside Police stated the UAV would not be replaced , citing performance problems and cost of staff training . In 2012 , the Ulster Society for the Prevention of Cruelty to Animals used a quadcopter UAV to deter badger baiters in Northern Ireland . In March 2013 , the British League Against Cruel Sports announced they had carried out trial flights with UAVs and planned to use a fixed - wing OpenRanger and an Octocopter to gather evidence to make private prosecutions against illegal hunting of foxes and other animals . The UAVs were supplied by ShadowView Ltd , Berkshire . A spokesman for Privacy International said that " licencing and permission for drones is only on the basis of health and safety , without considering whether privacy rights are violated . " The Civil Aviation Authority ( United Kingdom ) rules are that UAV aircraft less than 20 kilograms in weight must be in direct visual contact with the pilot , cannot fly within 150 meters of a congested area or within 50 meters of a person or vehicle , and cannot be used for commercial activity . Staffordshire police were reported to be using UAVs as alternatives to standard police support units in 2012 . UAVs over the United States . Surveillance and policing . UAVs can be powerful surveillance tools by carrying camera systems capable of license plate scanning and thermal imaging as well as radio equipment and other sensors . The Electronic Frontier Foundation filed a Freedom of Information Act request on January 10 , 2012 against the Federal Aviation Administration . As a result of the request , the FAA released a list of the names of all public and private entities that have applied for authorizations to fly UAVs domestically . Some of these government licenses belong to the U . S . Customs and Border Protection , a component of the Department of Homeland Security . UAVs have been used by U . S . Customs and Border Protection to patrol United States borders since 2005 , and the agency currently owns 10 UAVs . With plans to use armed drones . A May 2012 report issued by the DHS Inspector General found that CBP " needs to improve planning of its unmanned aircraft systems program to address its level of operation , program funding , and resource requirements , along with stakeholder needs " . Also , despite the Bureau ’ s limited mission to safeguard the borders , the Bureau often flies missions for the FBI , the Department of Defense , NOAA , local law enforcement , and other agencies . In December 2011 , the CBP made headlines when reporters discovered that the agency ' s UAVs were being used to assist local law enforcement in relation to cattle raiding in North Dakota without receiving prior approval from the FAA or any other agency . Individuals in the United States have few legal privacy protections from aerial surveillance conducted through UAVs . In Florida v . Riley , the United States Supreme Court held that individuals do not have the right to privacy from police observation from public airspace . The weakness of legal protection from UAV surveillance have led to calls from civil liberties advocacy groups for the U . S . government to issue laws and regulations that establish both privacy protections and greater transparency regarding the use of UAVs to gather information about individuals . As an example , the ACLU has warned of a " nightmare scenario " in the future where the police might be able , with computer technology , to combine mobile phone tracking with video data and build up a database of people ' s routine daily movements . In February 2013 Seattle mayor Michael McGinn ordered the Seattle Police Department to abandon plans to use UAVs after objections from residents . Two DraganflyerX6 craft had been purchased with a federal grant and the police had been granted FAA approval though they had not started using them . The vehicles were to be returned to the manufacturer . Seattle Police Department had announced in October 2012 that they were drafting a policy and they were one of the first police forces in the United States to receive approval from the federal government to use UAVs . Opponents of the programme included the Washington chapter of the American Civil Liberties Union . On February 24 , 2012 , the Electronic Privacy Information Center , joined by over 100 organizations , experts , and members of the public , submitted a petition to the FAA requesting a public rule - making on the privacy impact of UAV use in U . S . airspace . In June 2012 , Senator Rand Paul and Representative Austin Scott both introduced legislation that would require law enforcement to obtain a warrant before using a UAV to conduct surveillance of criminal activities . EPIC has stated that transparency and accountability must be built into the FAA ' s system of UAV / UAS / RPV regulation in order to provide basic protections to the public . While Congress rapidly moves ahead to authorize further use of domestic UAVs , many remain skeptical regarding privacy concerns . Some privacy scholars argue that the domestic use of UAVs for surveillance will ultimately benefit privacy by encouraging society to demand greater privacy rights . FBI Director Robert Mueller testified before the Senate Judiciary Committee on the 19th of June 2013 that the FBI owns and uses UAVs for the purposes of " surveillance " . Non - police uses . Law enforcement and other government agencies are not the only entities that use UAVs . Private citizens and media organizations use UAVs as well for the purposes of surveillance , recreation , or personal land assessment . Some farming initiatives utilize UAVs for crop spraying , as they are often cheaper than a full - sized helicopter . Occupy Wall Street journalist Tim Pool uses what he calls an " Occucopter " for live feed coverage of Occupy movement events . The " occucopter " is an inexpensive radio controlled quadcopter with cameras attached and controllable by Android devices or iOS . In February 2012 , an animal rights group used a MikroKopter hexacopter to film hunters shooting pigeons in South Carolina . The hunters then shot the UAV down . UAVs also have been shown to have many other civilian uses , such as agriculture , Hollywood , and in the construction industry . JFK International incident . In March 2013 an Alitalia pilot on final approach to runway 31 right at John F . Kennedy International Airport reported seeing a small UAV near his aircraft . Both the FAA and FBI were reported to be investigating . Virginia Bull Run crash . In August 2013 a UAV filming events at the Virginia Bull Run in Dinwiddie County , Virginia crashed into the crowd , causing minor injuries . Manhattan drone crash . In September 2013 a UAV flying over Manhattan collided with a building and crashed on the pavement below near a businessman who reported the incident to the police . The pilot seemed to lack experience controlling it as it collided with several buildings before the collision that made it crash . In October 2013 it was reported that a man had been arrested days after the incident had been reported in the media and that he had been charged with reckless endangerment . He was identified because he was seen in the video recorded by the drone . New York Drone Conference . In October 2013 , the ' Drones and Aerial Robotics Conference ' was held at New York University . The attendees included hobbyists and academics . A protest by Granny Peace Brigade against military and police use of drones was held outside . UAVs over Venezuela . In June 2012 , Venezuelan President Hugo Chavez claimed that Venezuela had begun producing its own UAV . General Julio Morales added that the UAV had a range of 100 kilometres ( about 60 miles ) , a maximum altitude of 3 , 000 metres ( about 10 , 000 feet ) , could fly for 90 minutes , measured three by four metres , and was a part of a system to survey and monitor pipelines , dams , and other rural infrastructure . General Morales was the president of the state - run Cavim arms manufacturer that developed the aircraft . UAVs over Vietnam . In May 2013 , The Vietnam Space Technology Institute successfully conducted 37 UAV flights in the central Lam Dong province . Research for the UAVs began in 2008 and was later funded by the state in 2011 . UAV operators . In the U . S . , thousands of civilian UAV operators work for contractors , piloting and maintaining UAVs . A 2011 study by the Air Force School of Aerospace Medicine indicated that nearly 50 % of spy UAV operators suffer from high stress - levels . The president of a civilian UAV operators ' union , the Association of Unmanned Operation ( AUO ) , cited long working hours and decreasing wages as U . S . involvement in wars in Iraq and Afghanistan was reduced and as a result of the U . S . government ' s budget sequestration . An August 2013 Brookings Institution study reported that there were approximately 1 , 300 remotely piloted aircraft ( RPA ) pilots in the U . S . Air Force , 8 . 5 percent of total Air Force pilots , up from 3 . 3 percent in 2008 . The study indicated that the U . S . military ' s combat air patrol ( CAP ) daily missions requirement is growing at a faster pace than RPA pilots can be trained , with an attrition rate during RPA flight screening being three times that of traditional pilots and a 13 % lower promotion rate to Major than other officers . Public opinion . In February 2013 , Fairleigh Dickinson University ' s PublicMind poll found that 48 % of American voters believe it is " illegal for the U . S . government to target its own citizens living abroad with drone attacks . Just 24 % say that it ' s legal . " " The public clearly makes an assumption very different from that of the Obama administration or Mr . Brennan : the public thinks targeting American citizens abroad is out of bounds , " Peter Woolley , founding director of PublicMind and professor of political science at FDU , said to CNN . In the same poll , however , by a wide six - to - one margin ( 75 % vs . 13 % ) , voters approved of the U . S . military using UAVs to carry out attacks abroad “ on people and other targets deemed a threat to the U . S . ” Republicans , men , and whites approve more strongly than Democrats , women , and non - whites , but approval is robust in all demographic categories . Voters also approve of the CIA using UAVs to carry out attacks abroad by a strong three - to - one margin ( 65 % vs . 21 % ) , but this approval is significantly less than approval for the U . S . military carrying out such attacks . Despite this broad - based public support , there are a number of vocal critics of the increasing use of UAVs to track and kill terrorists and militants . A major criticism of drone strikes is that they result in excessive collateral damage . David Kilcullen and Andrew Exum wrote in the New York Times that " according to Pakistani sources , they have also killed some 700 civilians . This is 50 civilians for every militant killed , a hit rate of 2 percent . " Other studies have put the civilian casualty rate anywhere between 4 and 35 percent . It is difficult to reconcile these figures because the drone strikes are often in areas that are inaccessible to independent observers and the data includes reports by local officials and local media , neither of whom are reliable sources . Critics also fear that by making killing seem clean and safe , so - called surgical UAV strikes will allow the United States to remain in a perpetual state of war . However , others maintain that drones " allow for a much closer review and much more selective targeting process than do other instruments of warfare " and are subject to Congressional oversight . Like any military technology , armed UAVs will kill people , combatants and innocents alike , thus " the main turning point concerns the question of whether we should go to war at all . " Morality . The “ unmanned ” aspect of UAVs is primarily what sets them apart from manned aircraft . This aspect also raises certain moral concerns . Some believe that the asymmetry of fighting humans with machines that are controlled from a safe distance lacks integrity and honor that was once valued during warfare . Others feel that if such technology is available , then there is a moral duty to employ it in order to save as many lives as possible . Another potential moral issue with UAVs is that because they do not allow for pilot casualties , some fear that they will be used more frivolously , and that human lives affected by UAV - based strikes will not be regarded with as much consideration as with manned aerial attacks . Legality . A confidential Justice Department memo concludes that the U . S . government can order the killing of American citizens if they are believed to be “ senior operational leaders ” of Al - Qaeda or “ an associated force ” — even if there is no intelligence indicating they are engaged in an active plot to attack the U . S . The secrecy surrounding such strikes is quickly emerging as a central issue in the hearing of White House counterterrorism adviser John O . Brennan , a key architect of the UAV campaign , to be CIA director . Brennan was the first administration official to publicly acknowledge UAV - based strikes in a speech last year , calling them “ consistent with the inherent right of self - defense . ” In a separate talk at the Northwestern University Law School , Attorney General Eric Holder specifically endorsed the constitutionality of targeted killings of Americans , saying they could be justified if government officials determine that the target poses “ an imminent threat of violent attack . ” But the confidential Justice Department “ white paper ” introduces a more expansive definition of self - defense or imminent attack than described by Brennan or Holder in their public speeches It refers , for example , to what it calls a “ broader concept of imminence ” than actual intelligence about any ongoing plot against the U . S . homeland . " The condition that an operational leader presents an ‘ imminent ’ threat of violent attack against the United States does not require the United States to have clear evidence that a specific attack on U . S . persons and interests will take place in the immediate future , ” the memo states . Instead , an “ informed , high - level ” official of the U . S . government may determine that the targeted American has been “ recently ” involved in “ activities ” posing a threat of a violent attack and “ there is no evidence suggesting that he has renounced or abandoned such activities . ” ( The memo does not define “ recently ” or “ activities . ” ) As in Holder ’ s speech , the confidential memo lays out a three - part test that would make targeted killings of American lawful : in addition to the suspect being an imminent threat , capture of the target must be “ infeasible , and the strike must be conducted according to “ laws of war principles . ” But the memo elaborates on some of these factors in ways that go beyond what the attorney general said publicly . For example , it states that U . S . officials may consider whether an attempted capture of a suspect would pose an “ undue risk ” to U . S . personnel involved in such an operation . If so , U . S . officials could determine that the capture operation of the targeted American would not be feasible , making it lawful for the U . S . government to order a killing instead , the memo concludes . The undated memo is entitled “ Lawfulness of a Lethal Operation Directed Against a U . S . Citizen who is a Senior Operational Leader of Al Qaeda or An Associated Force . ” It was provided to members of the Senate Intelligence and Judiciary committees in June 2013 by administration officials on the condition that it be kept confidential and not discussed publicly . Although not an official legal memo , the white paper was represented by administration officials as a policy document that closely mirrors the arguments of classified memos on targeted killings by the Justice Department ’ s Office of Legal Counsel , which provides authoritative legal advice to the president and all executive branch agencies . The administration has refused to turn over to Congress or release those memos publicly or to even publicly confirm their existence . A source with access to the white paper , which is not classified , provided a copy to NBC News . The white paper also includes a more extensive discussion of why targeted strikes against Americans does not violate constitutional protections afforded to American citizens as well as a U . S . law that criminalizes the killing of U . S . nationals overseas . It also discusses why such targeted killings would not be a war crime or violate a U . S . executive order banning assassinations . “ A lawful killing in self - defense is not an assassination , ” the white paper reads . “ In the Department ’ s view , a lethal operation conducted against a U . S . citizen whose conduct poses an imminent threat of violent attack against the United States would be a legitimate act of national self - defense that would not violate the assassination ban . Similarly , the use of lethal force , consistent with the laws of war , against an individual who is a legitimate military target would be lawful and would not violate the assassination ban . ”