Russia's A-100 AEW&C prototype aircraft makes maiden flight.

It can also guide fighters and bombers to hit detected air, ground and naval targets, the company said.

The A-100 aircraft, built on the base of the Il-76MD-90A transport aircraft, is expected to replace the A-50 AWACS aircraft currently in the service of the Russian Air Force.

The A-100 is a multifunction airborne intelligence, surveillance, reconnaissance (ISR), warning and control system. Essentially, it is an airborne headquarters using automated control systems to control friendly aircraft and air defense systems, designate targets for them and protect itself and nearby friendly planes by means of electronic countermeasures. The exact characteristics of the aircraft remain classified, but it is supposed to acquire enemy fighters at a range of more than 600 km and enemy ships at 400 km.

The delivery date of the A-100, which development commenced as far back as the early 2000s, has slipped behind schedule several times to date. Initially, the maiden flight was to take place in 2015, then it slipped to 2016 and - once the Il-76MD-90A had been selected as the carrier - it was postponed in 2011 for 2017.

The unique radar equipment, which flight tests are being carried out by the A-100LL, comprises a multiposition radar with two phased arrays as well as electronic intelligence and electronic warfare systems.

The A-100 is a rather classified program, but presumably, its radar relies on a unique technology, with the antenna array comprising small solid-state microwave elements and each element being dual-hatted as transmitter and receiver, expert Alexei Leonkov says. The solution both extends aerial and surface target acquisition range and boosts positioning accuracy by several times. Simply put, present-generation Russian and US AEW&C planes gauge a target’s coordinates using only the X and Y axes and calculating the target’s flight altitude - the Z axis - mathematically. The A-100 will measure the target’s coordinates by means of the three axes at once and, therefore, interceptors and air defense systems will not have to gauge the target’s coordinates in a more accurate manner - just launch their missiles.