IndiGo's passengers have been venting their frustrations over delays and cancellations by the airline over the past few days. The situation escalated yesterday, as more than 200 flights were cancelled and many more delayed—with disruptions spilling into today as well. 

Visuals from airports in major cities such as Mumbai, Bengaluru, Delhi, and Kolkata made the rounds on social media, showcasing disgruntled passengers waiting for hours and arguing with ground staff over delayed responses. 

In Hyderabad, more than 40 flights were cancelled; in Bengaluru the number was 42, while there were 85 cancellations in Mumbai. 

But what caused the snowballing of initial delays into a full-blown paralysis in operations? Fortune India explains: 

What exactly caused the disruption in IndiGo's operations?

IndiGo has been grappling with with shortage of cabin crew and pilots after the Directorate General of Civil Aviation (DGCA) implemented stricter norms from November 1, capping the number of landings between 12 am and 6 am, while increasing rest requirements. IndiGo and other domestic airlines pushed for postponing the rules, as they would need to require to hire more staff and train them in a short notice. 

Due to these rules, IndiGo flights remained on ground as there were no crew available to operate. A press note by DGCA on Wednesday said IndiGo cancelled 1,232 flights in November, of which 755 were due to crew and FDTL constraints, 92 by ATC system failures, 258 due to airport or airspace restrictions and 127 due to miscellaneous causes. 

What are the new norms under the the latest Flight Duty Time Limitations (FDTL) rules? 

The mandate implemented by DGCA is to increase rest periods and tighter restrictions on night operations to combat pilot and crew fatigue. 

Here are the following rules implemented since November 1:

• Increased weekly rest: The mandatory weekly rest period has increased from 36 hours to 48 consecutive hours.

What was IndiGo's response to the incident? 

An IndiGo spokesperson said that the carrier acknowledged that operations have been significantly disrupted across the network for the past two days, and apologised to the customers for the inconvenience caused.

As for reasons, the spokesperson mentioned "a multitude of unforeseen operational challenges including minor technology glitches, schedule changes linked to the winter season, adverse weather conditions, increased congestion in the aviation system and the implementation of updated crew rostering rules (Flight Duty Time Limitations) had a negative compounding impact" on their operations in a way that was not feasible to be anticipated.

What are IndiGo's plans to curb the disruption? 

"To contain the disruption and restore stability, we have initiated calibrated adjustments to our schedules. These measures will remain in place for the next 48 hours and will allow us to normalize our operations and progressively recover our punctuality across the network. Our teams are working around the clock to ease customer discomfort and ensure operations stabilize as quickly as possible," the statement read. 

The airline also added that the affected customers are being offered alternate travel arrangements to reach their destinations or refunds, as applicable.

Why were other airlines not affected in the same manner?

IndiGo's operations consist the majority of India's domestic flights. As per their website, they operate over 2,200 daily flights. Government data, along with DGCA's data indicate towards a sharp drop in its on-time performance, which declined to 35%, which is the complete opposite of IndiGo's tagline- "On time, every time". 

Meanwhile other carriers are small scale, which made it easier for them to adapt to the new norms and regulations. At the same time, Air India and Akasa operate on fewer night sectors, whereas Indigo runs high-frequency overnight services. The new rules capping night operations severely hit IndiGo's functions. 

How did other regulatory bodies react? 

The Federation of India Pilots (FIP) noted in a statement that the current disruption is a direct consequence of IndiGo's prolonged and unorthodox lean manpower strategy across departments, particularly in flight operations. 

“Despite the two-year preparatory window before full Flight Duty Time Limitations (FDTL) implementation, IndiGo inexplicably adopted a hiring freeze, entered non-poaching arrangements, maintained a pilot pay freeze through cartel-like behaviour, and demonstrated other short-sighted planning practices," the statement read. 

What is the next step by the DGCA? 

The DGCA is investigating the IndiGo flight disruptions and has summoned the airlines' officials for a meeting at noon today.  More details are awaited.