India, Nov. 12 -- Today marks a year since Vistara, the Tata-Singapore Airlines (SIA) joint venture, merged with Air India. Much has happened since then, including a deadly crash of an Air India flight in June that saw only one survivor.

One year on, the turnaround of Air India continues to be a work in progress but slower than what many would have imagined. The snail's pace, as critics would see it, is due to supply chain challenges, market dynamics and geopolitical challenges that have intensified since the merger.

At the time of the merger, the airline proudly showcased its combined fleet of 298 aircraft, including those of Air India Express. The Air India-Vistara fleet was at 208 then. A year later, the fleet is down significantly t...