The DRDO Airborne Early Warning and Control System (AEW&CS) is a project of India's Defence Research and Development Organisation to develop an airborne early warning and control system for the Indian Air Force. It is also referred to as NETRA Airborne Early Warning and Control System (AEW&CS). In 2003, the Indian Air Force (IAF) and DRDO carried out a joint study of the system-level requirements and feasibility of development for an Airborne Early Warning and Control (AEW&C) system.[3] The government then approved the project for the development of the AEW&C system by DRDO. Primary responsibility for the project was with Centre for Airborne Systems (CABS), which led the design, system integration and testing of the system. Electronics and Radar Development Establishment (LRDE) was responsible for the design of the radar array. The Defence Electronics Application Laboratory (DEAL), based in Dehradun, was responsible for the Data Link and Communication Systems for AEW&CS. The DRDO AEW&CS programme aims to deliver three radar-equipped surveillance aircraft to the Indian Air Force. The aircraft platform selected was the Embraer ERJ 145. Three ERJ 145 were procured from Embraer at a cost of US$300 Million, including the contracted modifications to the airframe. The project goal was to deploy these AEW&C aircraft by 2013. India's sole previous effort to develop an AEW&C system was the Airborne Surveillance Platform, but the programme, codenamed Airavat, was ended after the only test-bed crashed. The AEW&C project aimed to supplement the larger and more capable EL/W-2090 AWACS acquired by the IAF from Israel. Three EL/W-2090 systems have been ordered, with follow-on orders of 3 more expected in 2010. Apart from providing the IAF with a cheaper and hence, more flexible AEW&C platform as a backup to its more capable EL/W-2090 class systems, the DRDO AEW&C project aimed to develop the domestic ability to design and operationalise airborne surveillance platforms. The delivery of six additional systems ordered in October 2010 is to begin from 2015. In June 2010, it was reported that the Indian Air Force is said to be looking at acquiring up to 20 additional systems, in addition to the existing systems on order. Two radiating planar arrays assembled back-to-back and mounted on top of the fuselage in an active antenna array unit (AAAU) will provide 240° coverage like Erieye. The AAAU is configured to compactly house 10 × 2 antenna array panels, 160 transmit receive 10 × 2 antenna array panels, 160 transmit receive multi-modules (TRMMs) dividers, beam forming units, beam control units, power supply units and related electronic devices including cables and connectors. This has been achieved through an innovative and iterative process to arrive at the AAAU with minimal dimensions and optimum mass properties. A unique feature of this Indian TRMM design is that eight trans-receive modules are combined compactly to form a single TRMM, thus facilitating high density installation of 160 of them in the AAAU to power the surveillance radar. Additionally, the aircraft has other mission capabilities like identification friend or foe (IFF), electronic and communication support measures, C-band line-of-sight and Ku-band SATCOM datalinks, etc., similar to those on the AWACS and CAEW systems. The important modes of operation of the primary radar system are the surface surveillance and the air surveillance. The sensor has the abilities to search, track-while-scan, priority tracking, high performance tracking, etc. In priority tracking, the targets will be placed in full track mode even if these cross the primary surveillance area. In high performance tracking, additional measurements will be made to improve the tracking accuracy. Utilising active aperture technology, the radar provides a fast-beam agile system that can operate in several modes concurrently. Inter-operability with AWACS, other AEW&C aircraft, fighters and ground-exploitation stations is ensured using the data-links with voice and data channels. The aircraft cabin houses five operator work stations to adequately meet requirements of the operational mission tasks. An air-to-air refuelling system enables extended operations at times of need. The endurance of the platform aircraft is about nine hours with one air-to-air refuelling. The first combat usage of the Netra AEW&C by the IAF was on 26 February 2019, during the Balakot airstrike. Indonesia has requested a systems demonstration. For further details, including specifications and performance, click here for Embraer ERJ and here for R-99.