ASR has different reality. Most of the Punjabi population are going to UK or Canada and so ASR is the case that it is a immigrant capital. If demand is high then why is BA or AA not running? BA stopped due to lack of demand I believe. AI might resume but AI is of no use to regular middle class travellers, too costly, its more costly than Emirates and service doesn't even compare to Emirates. I'd rather take CCU-Abu Dhabi-LHR Emirates than direct CCU-LHR AI. (I actually use the JFK-AUD-CCU a lot, as I'm a regular in JFK-CCU route ). Also CCU's international terminal is ancient. They gotta ramp it up. It's nowhere compared to BLR or DEL or BOM