As part of the programme, CABS has this week signed a contract with Adani Defence Systems and Technologies Limited (ADSTL) as the Development-cum-Production Partner (DcPP) for the indigenous mission systems that will be installed on the aircraft.The contract also includes integrated logistics, maintenance, repair and overhaul, and technical support for up to 30 years.It also simultaneously signed a contract with state-owned AI Engineering Services Limited (AIESL) to convert six A321 aircraft, acquired by the IAF from Air India, from commercial passenger configuration into what is known as a “green aircraft”.A green configuration means that the aircraft is stripped of all commercial interiors, including passenger seats, overhead bins, cabin fittings and associated equipment, leaving behind only the basic aircraft structure and essential wiring. This creates the platform on which the specialised military systems can later be installed.Once this conversion is completed in India, the aircraft will be flown to Airbus facility in Spain, where the original equipment manufacturer (OEM) will undertake extensive structural and aerodynamic modifications necessary to transform a commercial airliner into an airborne early warning platform.According to sources in the defence establishment, these modifications go far beyond simply installing the large radar housing on top of the aircraft.“There are multiple design changes that have to be carried out. You cannot simply mount the rotodome because that changes the aircraft’s centre of gravity,” a source explained.“There are structural reinforcements, power generation requirements, cooling systems and a host of other modifications. Since Airbus is the OEM, it is best placed to undertake these changes.”The involvement of Airbus follows a contract signed by CABS with the European aerospace major in December last year for supporting the platform modification programme.More than 100 sensors onboard