Photo credit: Airbus
NEW DELHI: In a major safety-enhancement move, the Directorate General of Civil Aviation (DGCA) on Thursday got a “satellite-based landing system (SLS)” approach conducted for the first time on a jet engine aircraft in India. The regulator got the flight operated on an IndiGo Airbus A320 into Udaipur using ISRO and Airport Authority of India’s satellite-based navigation system GAGAN (GPS aided geo augmented navigation). Jet engine planes have jumped on the bandwagon a few years after a turboprop ATR had done so.SLS is seen as a game-changer in terms of enhancing safety at secondary airports that do not have expensive instrument landing system (ILS) installed, as it allows the use of new satellite navigation technologies to perform approaches. SLS first entered service in Europe with the A350 in 2015.Officials in the know say the IndiGo Airbus flight to Udaipur was “another significant milestone in advancing satellite-based navigation in India by successfully conducting a localiser performance with vertical guidance (LPV) approach.” IndiGo had introduced LPV operations on its ATR fleet in 2022 and has now expanded “satellite-based augmentation system” (SBAS) enabled operations across its fleet. Jointly developed by ISRO and Airports Authority of India (AAI), India’s SBAS GAGAN provides the coverage needed for LPV procedures across Indian airspace and positions India as one of the few countries worldwide with its own SBAS capability. AAI has been publishing LPV approach procedures across airports in the country. At present, 23 LPV approaches have been published, with the number expected to exceed 40 by the end of the year. As more airports adopt LPV procedures and more airlines equip their aircraft with SBAS capability, GAGAN is expected to play a central role in the future of Indian aviation by making air travel safer, more efficient and more accessible.The demonstration flight is a milestone in Directorate General of Civil Aviation’s (DGCA) regulatory approval process before LPV procedures can be introduced into regular commercial operations on IndiGo’s Airbus fleet, say sources.“For decades, aircraft have relied on ground-based navigation systems to guide pilots safely to the runway, especially during poor weather or low visibility. While these systems have served aviation well for decades, they are expensive to procure and maintain. SBAS has fundamentally changed the way aircraft navigate and land. It enhances accuracy, integrity, and availability of standard GNSS signals by broadcasting correction data from geostationary satellites. Instead of depending solely on equipment installed at airports, SBAS allows pilots to receive precise horizontal and vertical guidance while approaching the runway, even at airports that do not have conventional precision landing systems. The technology enhances safety, reduces operational disruptions and improves overall efficiency for both airlines and passengers,” said a senior pilot.In a document on SLS, aerospace major Airbus says: “This function enables pilots to perform ‘straight-in’ approaches using satellite positioning into airports, even in low-visibility conditions… Facilitating precision approach access to secondary airports SLS capability enhances the airlines’ operations by enabling stable approaches especially at airports currently not having precision approach means; at main runways as a backup to ILS (like during maintenance), or at alternate airports in case of diversion.”“Almost half of recorded controlled flight into terrain accidents occurred during approach and landing without vertical guidance. SLS allows approaches with vertical and lateral guidance to 200 ft above the ground, without expensive ground installation like ILS,” said an official overseeing this exercise on condition of anonymity.
