Who needs a pilot? Not Farnborough's UAVs (photos)

The Global Hawk, built by Northrup Grumman, features a bulging forehead common among UAVs. This model is built for NATO's ground surveillance program; other variations include a maritime version for the United States Navy and a signals intelligence version for the German Ministry of Defense. The Global Hawk was one of many UAVs on display at the Farnborough International Airshow in England.

Many UAVs are designed only for surveillance, but Israel Aerospace Industries' Harop has a more active military role: It's a bomb that can loiter above a battlefield then attack self-destructively when a target is detected. It can attack anywhere from horizontally or vertically, the latter being important in urban environments, the IAI said.

The 420-pound Sentry can fly for as much as 6 hours and carry a payload weight up to 75 pounds. It's built by Finmeccanica Group's DRS Technologies division.

One prime duty of UAVs is surveillance. The Sky-Y unmanned aerial vehicle, a demonstration craft built by Finmeccanica's Alenia Aeronautica division, features multiple sensors in this pod.

Not all UAVs are fixed-wing craft. Northrup Grumman's MQ-8B Fire Scout, sold to the United States Navy and other customers, is a helicopter design that can be equipped with modules for communications relay, land mine detection, electronic eavesdropping, and observation. It was on display at the Farnborough International Airshow.

The watertight Neptune is designed for marine environments and comes with a portable compressed-air launcher. The 135-pound craft lands by parachute and must be retrieved afterward. It's got a 7-foot wingspan and is built by Finmeccanica Group.

The Falco from Finmeccanica Group has a 23.6-foot wingspan and can carry as much as 140 pounds. It can remain aloft for as long as 8 to 14 hours. Among its uses are observation, laser targeting, and radar.

Textron Systems' RQ-7 tactical UAV, called the Shadow, in service with the U.S. Army and Marine Corps, is shown here on its launch system. It's got a 14-foot wingspan and can loiter as slow as 69 miles per hour and cruise at 104mph.

The Sky-Y unmanned aerial vehicle is a demonstration craft built by Finmeccanica's Alenia Aeronautica division. The propeller-driven craft is designed to fly as long as 15 hours.

Aeronautics' Aerostar is a UAV with a 155-mile range, 25-foot wingspan, and 121-pound payload capacity. It can fly as long as 12 hours and as high as 18,000 feet. It's geared for finding targets, designating them for attack, and other military tasks. The Israeli Intelligence Corp assisted in its design, and among its customers are the U.S. Navy, Angola, and the Israel Defense Forces.