After flying high in the June quarter, IndiGo’s earnings took a sharp turn as the airline posted a net loss of Rs 2,582 crore for the September quarter. The reversal comes despite steady growth in operations and passenger traffic, with revenue rising 9% year-on-year (YoY) to Rs 18,555 crore, according to an ET report. In contrast, the carrier had reported a profit of Rs 2,176 crore in the previous quarter.The September setback marks a deeper loss than the Rs 987 crore recorded a year earlier, with the impact of foreign exchange fluctuations wiping out profitability. Excluding the forex hit, IndiGo said it would have earned a net profit of Rs 104 crore.IndiGo attributed the loss primarily to currency movement, which affects costs such as aircraft leases, maintenance, and fuel payments — all largely denominated in US dollars. A weaker rupee inflates these costs in rupee terms, squeezing margins even when dollar prices remain steady.The airline’s EBITDAR more than halved to Rs 1,114 crore from Rs 2,434 crore last year, reflecting cost pressure despite healthy operational metrics.Passenger ticket revenues increased 11.2% YoY to Rs 15,967 crore, while ancillary revenues — from seat selection, baggage, and meals — rose 14% to Rs 2,141 crore. However, total expenses surged 18% YoY to Rs 22,081 crore, led by higher maintenance, airport, and staff costs.While fuel expenses fell 10% to Rs 5,962 crore, IndiGo’s cost per available seat kilometre (CASK) rose 10% to Rs 5.16. Excluding fuel, CASK jumped 25% to Rs 3.71, signalling cost inflation across non-fuel items.Passenger yields improved 3.2% to Rs 4.69 per km, while RASK (revenue per available seat kilometre) rose 2.3% to Rs 4.55.“As India’s aviation sector continues to grow and mature, we recognize the importance of structurally optimizing capacity during seasonally weaker periods to sustain profitability,” said Pieter Elbers, CEO, IndiGo.Elbers added that IndiGo delivered “a very strong operational performance,” maintaining its leadership in on-time performance, customer satisfaction, and network expansion.IndiGo’s stock ended 1.1% lower at Rs 5,630 on NSE, as investors remained cautious about the impact of forex volatility on the airline’s bottom line despite resilient demand.