Airborne Early Warning
From Wikipedia, the free encyclopedia
An Airborne Early Warning (AEW) system is a radar system carried by an aircraft which is designed to detect other aircraft. Used at a high altitude, the radars allow the operators to distinguish between friendly and hostile aircraft hundreds of miles away.
AEW aircraft are used for defensive and offensive air operations. The system is used offensively to direct fighters to their target locations, and defensively to counter attacks.
Many countries have their own AEW systems, although the E-3 Sentry and Grumman E-2C Hawkeye are the popular systems worldwide. The Sentry was built by the Boeing Defense and Space Group (now Integrated Defense Systems) and is widely considered to be an international benchmark for AEW systems. It is based on the Boeing 707 aircraft. The E-2 Hawkeye, which entered service in 1965, is arguably the most widely used AEW system. The E-3 Sentry is not strictly an AEW system, as it has far more functionality. See Airborne Warning and Control System. For the Japanese Air Self-Defense Force, the E-3 technology has been fitted into a Boeing B-767.
The United Kingdom first deployed an AEW capability on the Fairey Gannet AEW 3, using the AN/APS 20 radar. When the Gannet was withdrawn, the RAF deployed the radars taken from the Gannets on Shackleton MR2 airframes to make the AEW 2. This became the last piston engined aircraft in the RAF, and as a point of interest it was also a tail wheel aircraft. To replace this, they started to develop the Nimrod AEW.3, developed by De Havilland. However, the Nimrod AEW programme was cancelled just as the prototype completed its final trials in favor of procuring the E-3 (powered by CFM56 engines) from the US.
The Russian Air Force is currently using around 15-20 Beriev A-50 'Mainstay-A'/A-50U 'Mainstay-B' in the AEW role. The Mainstay is based on the military/comercial Il-76 'Candid' airframe, with a large non-rotating radome on the rear fuselage.
The RAAF are deploying Boeing 737-based aircraft under Project Wedgetail. Unlike the E-2 and E-3, Wedgetail does not have a rotodome. It will probably be marketed towards many existing E-2 customers, who would otherwise have no choice but to purchase a system intended for an aircraft carrier, due to lack of options.
The Swedish Air Force use the S 100B Argus as their AEW platform. The S 100B Argus is based on the Saab 340 with an Ericsson Erieye PS-890 radar.
The Brazilian Air Force and Mexican Air Force use the Embraer R-99 with an Ericsson Erieye PS-890 radar, same for S 100B Argus.
In early 2006 the Pakistan Air Force ordered 6 Saab 2000 fitted with Erieye AEW systems from Sweden in a deal valued roughly $1bn. In December 2006 the Pakistan Navy requested 3 excess P-3 Orion aircraft equipped with Hawkeye 2000 AEW systems, the overall cost of the program is $855mn. China and Pakistan also signed a Memorandum of Understanding (MoU) for the joint development of Airborne Early Warning & Control (AEW&C) systems.
There are only three helicopter-based AEW platforms in existence. One is the Royal Navy Westland Sea King ASaC7 naval helicopter. It is operated from the Royal Navy's Invincible class aircraft carrier (HMS Illustrious and HMS Ark Royal). The creation of Sea King ASaC7, and earlier AEW.2 and AEW.5 is the consequence of the harsh lessons learnt by the Royal Navy task force sent to the South Atlantic in the 1982 Falklands War. The lack of AEW coverage for the task force was a major tactical shortcoming at the time.
Another Helicopter is Russian Built Ka-31 Helix-B, deployed by Indian Navy on Krivak-III Frigates and reportedly used by the Russian Navy on its sole Kuznetsov aircraft carrier. It is fitted with E-801M Oko (Eye) airborne electronic warfare radar which can track up to 20 targets simultaneously with aerial detection range 150 km and surface warships up to 250 km. The Indian Air Force ordered three IAI Phalcon systems in 2004 that will be delivered in 2007. Also India is developing its own version of an AEW aircraft that will be available to the IAF by 2010.
The most modern helicopter-based AEW is the AgustaWestland EH101 AEW of the Italian Navy.
Some AEW systems feature additional command and control functionality, AWACS aircraft. These are often referred to as Airborne Early Warning and Control (AEW&C) systems.
