India, Jan. 6 -- Less than a fortnight after its much-hyped launch, the Navi Mumbai International Airport (NMIA) is facing turbulence on the ground. Passengers flying through the new terminal have flagged serious gaps in mobile connectivity, last-mile transportation, lighting, and signage, which is denting the promise of the Mumbai metropolitan region's long-awaited second international airport.

Total digital blackout

The most immediate and disruptive problem, passengers say, is the near-total absence of mobile network coverage inside the terminal. Calls drop, mobile data is unavailable, and app-based payments frequently fail, forcing travellers to rely almost entirely on the free airport Wi-Fi for basic tasks, such as contacting family...