The Civil Aviation Ministry has said aircraft manufactured before July 2021 cannot be made Gagan complaint due to technology challenges. In a statement, the government said, "Aircraft, wherein the aircraft/avionics OEMs have communicated that the aircraft cannot be made GAGAN compliant due to technology challenges and the possibility of the design change is not feasible and the same has been ascertained by DGCA and Aircraft which have been manufactured prior to 01.07.2021 may be exempted from the GAGAN mandate."


Gagan is an Indian Satellite Based Augmentation System (SBAS) jointly developed by AAI and ISRO. It is the first such system developed for India and neighboring countries in the equatorial region. GAGAN System was certified by DGCA in 2015 for Approach with Vertical Guidance (APV 1) and en-route (RNP 0.1) operations. There are only four Space-Based augmentation systems available in the world namely India (GAGAN), US(WAAS) Europe (EGNOS) and Japan (MSAS). Gagan is the first such system developed for India and neighboring countries in the equatorial region.


AAI in coordination with Indian National Centre for Ocean Information Services (INCOIS) has implemented GAGAN Message Service (GMS) through which alert messages to fishermen, formers, and disaster affected people will be sent on the occurrence of natural disasters, calamities, such as flood, earthquake etc. The additional capabilities of GAGAN are also being explored to utilize it in non-aviation field such as Railways, Surveying, Agriculture, Power sector, Mining etc. 


Design of GAGAN procedures require meticulous survey of the airport environment surroundings and obstacle surfaces. These data are correlated with the complex aircraft approach maneuvers and further simulated in a software to ensure safety of the procedure designed. These procedures can be developed for any of the airport in India for landing without help of Instrument Landing System.


These types of procedures make aircraft to land in low visibility condition almost equivalent to Category-1 Instrument Landing System (ILS).