just a quick update. My AI 173 flight from BLR was ten minutes late getting into DEL. I did complete customs/passport check in BLR. Unfortunately, the flight was diverted to a remote stand and we had to be bused into the transfers area. AI did have a special bus for premium class passengers. We had to wait about 15 minutes for the bus as the ground staff did not have a bus waiting for us.
With just under an hour to make my flight to IAD (AI 103), it was a close one. The transfer security check area was chaotic with close to 100+ in lines. Again, fortunately one of the ground handlers was asking to see who was traveling to IAD and helped us to get to the front of the line. The gate (#3) was quite far from the transfer security check area.
There are no separate security check lines for F/J passengers.
I did make the flight with less than ten minutes to spare.
if I were to repeat this, I would definitely take an earlier flight.