ISRO's satellite-based system

Last Friday, an IndiGo A320 landed at Udaipur airport guided entirely by satellites. 

GAGAN, ISRO's satellite-based augmentation system, corrects GPS signals in real time from space.

Here is why that matters. A standard Instrument Landing System, the ground hardware that lets pilots land in low visibility, costs millions to install and maintain.  For an airport handling four flights a day, the math never works. So most of India's tier-2 and tier-3 airports run on visual approach. Pilots descend until they can see the runway. If the clouds do not cooperate, they need to divert. Anyone who has flown into a hill station knows what that feels like.

UDAN spent nearly a decade trying to fix regional connectivity, subsidizing routes into existence. However many airports were not equipped to guarantee safe landing. GAGAN solves exactly that. AAI has already published 23 LPV precision approach procedures, with 40+ airports targeted by year end.

A pilot still cannot choose the weather. But for the first time, an airport can guarantee the landing.