Delhi Noida Airport opens – what will be the impact on Indira Gandhi?

India is on something of an airport building boom to match the dramatic increase in passenger numbers within, from, and to it.

India and South Asia's passenger air traffic will rise by an average of 7% annually over the next 20 years, spurred by a growing middle class, economic growth, and airport and connectivity investments.

Even so, the opening of two new airports in the last six months - at India's leading commercial city, Mumbai, and now at the capital, Delhi - will always create headlines.

Both airports are secondary ones to the long established primary airports and will be slow to get going, even if their ultimate capacity is high. In the case of Delhi's Noida airport it just opened with only two airlines, both serving only domestic routes.

But Noida will grow quickly and the pressing question is how much traffic will it draw away from Indira Gandhi International?