Washington ( CNN ) -- Unmanned aircraft patrolling the nation 's borders have an accident rate seven times greater than general aviation aircraft , and hundreds of times greater than the rate of jetliners , federal officials said Thursday in urging caution in expanding the use of pilotless planes . Unmanned aerial vehicles , or UAVs , have proven remarkably useful in the skies over Iraq and Afghanistan , but are difficult to integrate into U.S. skies , the most complex airspace in the world , FAA official Nancy Kalinowski said in testimony before a House Homeland Security subcommittee . Kalinowski said the accident rates for Customs and Border Protection ( CBP ) aircraft are based on a relatively limited use of the planes -- only 5,688 flight hours . But because of the limited data , `` the FAA must make conservative decisions '' concerning integrating UAVs into U.S. skies , Kalinowski said . It is the FAA 's responsibility to ensure the safety of other planes in the sky as well as people on the ground , she said . Increasingly , government agencies , police departments and private businesses have pushed the FAA for expanded use of UAVs . CBP currently operates six UAVs and will get a seventh by the end of the year . The CBP accident rate is 52.7 accidents per 100,000 flight hours , Kalinowski said . The accident rate for general aviation aircraft is 7.11 accidents per 100,000 flight hours , and 0.149 accidents for commercial aircraft . Public operators of UAVs such as the government and universities must obtain a special FAA certificate of waiver or authorization before operating in U.S. civil airspace . Civil users can get permits for research and development , demonstrations and crew training , but commercial UAV operations are not permitted at this time .
Unmanned aircraft have higher accident rates than regular aircraft . The FAA urges caution in expanding the use of pilotless planes in the United States . An FAA official told a House subcommittee that the agency must make conservative decisions on the issue .