United States fly high: while the United States and the Soviet Union were the first to re-explore uncrewed aircraft technologies since the second world war in the 1960s, notably through Ryan and Tupolev , Israel was really the first nation to turn the discipline into a viable proposition in the 1980s, before being overtaken in terms of market size by the United States

Armada International, June-July, 2008 by Roy Braybrook

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Compared to spending on manned aircraft (the Lockheed Martin F-22 alone receiving over $ 3.5 billion in FY08), that on drones is small, but rising impressively. The Washington-based Teal Group estimated in late 2007 that the worldwide annual spend on drones will almost double from the current $ 3.4 billion to around $ 7.3 billion within a decade, thereby making this the most dynamic growth sector of the aerospace business.

The Pentagon's own forecasts show its unmanned aircraft procurement budget rising steadily from $ 878.4 million in FY07 to a peak of $ two billion in FY10. In the latter year, America's corresponding RDT&E expenditure is predicted as $ 1.3 billion and operating & maintenance as $ 421.2 million.

The US armed services are estimated to already have a total of around 5300 drones in their inventories, and this number is clearly set to rise dramatically. Procurement of the Aerovironment (AV) RQ-11 Raven alone is aimed at 3333 systems, each with three air vehicles. The Raven has been flying over 12,000 hours/month, and is expected to fly 300,000 in 2008.

The US military drone flying total was 165,000 hours in FY06, and 258,000 in FY07. Even when small hand-launched systems are excluded, American drones are currently flying over 15,000 hours per month in southwest Asia. The AAI RQ-7 Shadow 200 is contributing over 7000, the General Atomics MQ-1 Predator over 6000 (out of a global total of more than 10,000), the Northrop Grumman MQ-5 Hunter around 1700 and the Northrop Grumman RQ-4 Global Hawk over 500 hours.

Lighter-than-Air

Uncrewed lighter-than-air vehicles exploit the drone's freedom from the constraints of human endurance. The systems used operationally by the US Army are the Raytheon/Tcom Raid (Rapid Aerostat Initial Deployment), the Lockheed Martin/ISL-Bosch Aerospace Reap (Rapidly Elevated Aerostat Platform) and the Lockheed Martin PTDS (Persistent Threat Detection System). The Raytheon/Tcom Jlens (Joint Land Attack Elevated Netted Sensor) is being developed to warn deployed US forces of cruise missile attack.

Other nations using aerostat-mounted sensors include Israel, with Elta EL/M-2083 radars on Tcom platforms. India has bought similar systems. Israel also operates the Tcom 32M aerostat with EL/I-3330 radar. Pakistan uses the ILC Dover Tars (Tethered Aerostat Radar System), developed for the US Air Force. The United Arab Emirates use the Tcom Tas (Tactical Aerostat System) with 17M and 71M balloons.

Hale

The leader in the Hale (high altitude, long endurance) category is still the Northrop Grumman RQ-4 Global Hawk. The first of seven YRQ-4A development aircraft flew in 1998. Nine production RQ-4A Block 10s (seven for the US Air Force and two Global Hawk Maritime Demonstration aircraft for the US Navy) have been followed by six stretched RQ-4B Block 20s, with gross weight increased to 14,628 kg. The first of 26 RQ-4B Block 30s with 'multi-intelligence' payload including Asip (Advanced Signals Intelligence Program) was delivered to the US Air Force in late 2007. The service plans to buy up to 15 RQ-4B Block 40s with the Northrop Grumman/Raytheon MP-Rtip (Multi-Platform Radar Technlogy Insertion Program) sensor, giving it a total of 54 production aircraft. Two of the YRQ-4As have been assigned to Nasa/Dryden. Three RQ-4A Block 10s are deployed with US Central Command (and reportedly based in Qatar) for missions over southwest Asia.

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The US Air Force FY09 budget request includes five RQ-4B Block 40s for $ 712.2 million. Northrop Grumman has quoted a unit flyaway cost of $ 66.3 million for a Block 40, including a $ 39 million payload. In 2007 Washington formally declined to sell RQ-4s to South Korea until MTCR regulations are changed.

On 22 March 2008, an RQ4--the first Global Hawk Block 20--surpassed both the official and unofficial world un-refuelled endurance records by completing a mission of 33.1 hours at altitudes of over 60,000 ft over Edwards Air Force Base.

In January 2007 EuroHawk, a joint venture by Northrop Grumman and Eads, was awarded a $ 559 million contract by the German Ministry of Defence to build the Euro Hawk sigint, surveillance and reconnaissance system, a derivative of the RQ-4B Block 20, with a payload developed by Eads. The first contract includes one Block 20 to be delivered in 2010. The remaining four air vehicles are planned for delivery in 2011 and 2014.

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The RQ-4B has also been selected for Nato's Alliance Ground Surveillance (AGS) programme, now to be based on eight off-the-shelf RQ-4B Block 40s. Northrop Grumman will be prime contractor, supported by various companies from the 21 participating nations.

Bams

The latest major win for the RQ-4 is the US Navy's Barns (Broad Area Maritime Surveillance programme, which is estimated to be worth around $ 3.08 billion (including $ 780 million for the procurement of three initial production aircraft) over the next five years. A further 62 production aircraft are expected to cost $ 3.4 billion in current values.