(a) the income generated from international airlines and their international flights passing through Indian Air Zones and also for the use of airport and airstrip in landing and takeoff during the last three years and the current year, airport/year-wise;
(b) the list of foreign airliners of both passenger and cargo planes using Indian airstrips and air navigation system;
(c) whether the Government has taken any measures to increase the state of art technology at Chennai Air Traffic center for providing the navigation signals; and
(d) if so, the details thereof and total expenditure incurred during 2014-15, 2015-16 and 2016 till date for installation and commissioning of such gadgets?