The function of a combat surveillance UAV is to observe events on a battlefield in real-time, orbiting over the battle area and relaying intelligence to a ground control station.
Other specialized payloads, such as SIGINT packages, or new lightweight synthetic aperture radar (SAR)sensors with all-weather imaging capability, are now being fielded as well.
The smaller combat surveillance UAVs, in the size range of a large hobbyist RC model plane and used to support military forces at the brigade or battalion level, are sometimes called "mini-UAVs", and their low cost makes them particularly suitable for "expendable" missions.
In the early 1960s, the US Navy obtained a small "Drone Anti-Submarine Helicopter" (DASH) Gyrodyne QH-50 that could fly off a frigate or destroyer to carry homing torpedoes or nuclear depth charges for attacks on enemy submarines that were out of range of the ship's other weapons.
This was a relatively simple requirement, involving a neatly defined mission in a combat environment where presumably nobody would usually be shooting back at the drone, and it seemed achievable with the technology of the time.
The order was cut to a little over 500, with final production being the "QH-50D" variant, with an uprated engine providing 274 kW (365 shp), fiberglass rotors, and increased fuel capacity.
A small number of DASHes were apparently given reconnaissance gear and used for naval surveillance over the Gulf of Tonkin in 1966 in a project codenamed SNOOPY.
In the early 1970s the Air Force evaluated the QH-50D for a battlefield drone test program codenamed NITE GAZELLE.
While it appears the Pegasus was not a success, the DASH was resurrected a second time in the 1990s by the German Dornier company, now part of Daimler Chrysler, for the "SEAMOS" naval UAV.
Like the original DASH, SEAMOS was a coaxial-rotor drone helicopter with twin landing skids, though it was unsurprisingly a more refined system, and in particular even had a real fuselage.
The German government put out a request for an off-the-shelf solution, sensibly stating specifications in line with a machine that they could afford.
It was a "symmetrical delta", meaning it didn't matter if it flew upside-down, allowing it to offer some protection to its payload when necessary.
Beginning in the mid-1970s, the USAF Flight Dynamics Laboratory, working with Teledyne Ryan, developed a piston-powered tactical UAV designated the "XBQM-26 Teleplane".
The BRAVE 200 was intended to be used as an antiradar attack drone, a jamming platform, or for other expendable battlefield missions.
The BRAVE 200 effort began in 1983, when the company received a USAF contract to develop an anti-radar attack drone, under the designation "YCQM-121A Pave Tiger".
Further evaluation of the Hunter based on these seven systems demonstrated more shortcomings in the UAV's software, data link, and engine.
In the spring of 1999, eight surviving Hunters, redesignated "RQ-5A", were sent to Albania to support OPERATION ALLIED FORCE, the NATO air campaign against Serbia.
NATO commander Wesley Clark used the video feeds and on a few occasions contacted the Hunter operations team directly.
They spotted targets such as air defense radars, artillery, and missile launchers, and usually stayed on station during attacks to perform post-strike damage assessment.
In fact, the Hunter has proven so useful that the Army plans to buy more of them, suggesting that reports of its death in 1996 were greatly exaggerated.
A test drop of four BATs performed in early October 2002 scored three direct hits on armored vehicle targets, with one of the three blowing the turret off the tank it struck.
By the summer of 2004, the type had achieved a total of 30,000 flight hours in US Army service, not bad for an aircraft that was formally "canned".
Although the Hunter proved very useful almost in spite of itself, the Army still needed a formal operational battlefield UAV system.
It was powered by a four-cylinder piston engine driving a pusher propeller, had fixed landing gear, and a pancake-shaped data link antenna on its back.
The weather in the Middle East is generally hot, sunny, and clear, and the Israelis have a relatively fixed set of adversaries who mostly live right on their border.
This was unavoidable, but it also opened the door to adding ever more specifications, a bureaucratic process known as "feature creep" that can squeeze the life out a project.
On the other hand, some defense engineers approached UAVs with the same mindset as they would use for building a piloted aircraft, causing costs to skyrocket.
This meant increasing the UAV's range by a factor of four, to allow ships to see targets over the horizon, and specifying an engine that ran on diesel fuel, not gasoline, which is too flammable to store on a naval vessel except when the need absolutely demands it.
Not only does having such a prominent patron eliminate obstacles, it also encourages program officials to greater efforts, since they know their actions have high-level visibility.
In addition, the Navy's long and difficult search for an antiship missile target, discussed earlier, suggests that the Army has no particular copyright on bumbling.