The Israel Air Force and Ground Forces Command have issued a request to defense industries to submit proposals for the development of a stealthy unmanned aerial vehicle (UAV) that would be capable of flying undetected in combat zones. Defense officials said that the envisioned UAV would reach relatively low altitudes of 3,000 feet and be capable of conducting surveillance missions for up to 10 hours. "This will need to be a very quiet UAV so it can retain the element of surprise for forces operating in enemy territory," one official explained. "The new UAV will achieve this quiet through a combination of a new propulsion system, size and composite materials." According to a report in Defense News, request for proposals did not specify a preferred propulsion system, although the program's emphasis on covert operations would likely favor electric engines, which are quieter than those that operate on gas. Officials said that the program would cost tens of millions of dollars and would eventually lead to the deployment of UAVs in all IDF brigades to supplement the Sky Rider UAV, which will be deployed at the battalion level. Likely contenders for the tender include Elbit Systems, Israel Aerospace Industries (IAI) and Aeronautics. "The battalion UAV will provide surveillance on a tactical, pinpointed level," the official said. "The new, larger UAV will be able to provide brigade commanders with a larger picture of the battlefield." The decision to develop a new UAV comes amid IDF plans to increase the use of drones in military operations. In an effort to increase its intelligence-gathering capabilities, the IAF will in the coming months establish a new squadron of Heron TP Unmanned Aerial Vehicles (UAVs), called the Eitan, manufactured by IAI. The Heron TP is the largest Israeli UAV, with a 26-meter wingspan, the same as a Boeing 737. It weighs 4,650 kilograms and can fly at an altitude of up to 45,000 feet. The Heron TP is capable of reaching Iran and, according to Defense News, is capable of carrying more than a ton of weapons as well as specialized sensors, electronic warfare and targeting gear in its forward section, its principal payload bay and on each tail of its twin boom.