Airlines at airports across the world have experienced flight delays and cancellations after a broken software update wreaked havoc on most of the world's Windows-operated computers. At certain airports — including Delhi Indira Gandhi Int’l (DEL) — flight staff had to board flights with pen and paper.

Software Update Gone Wrong 

On Friday July 19, a software update issued by cybersecurity firm Crowdstrike was issued to Microsoft Windows computers around the globe. However, a “defect” in this update has been causing computers across the globe to crash and display a blue error screen.

This issue has caused disruptions to nearly every industry across the globe, with the aviation industry and passenger airlines being hit especially hard. Most airlines across the world rely on Microsoft Windows computers for their day-to-day operations such as online and airport check-in.

Delays Across the Globe 

Due to the software update and subsequent issues that came with it, over 3,500 flights across the globe were canceled, with thousands more being delayed for hours. 

In the United States, all three major U.S. airlines — United, Delta, and American — issued ground stops early in the morning on July 19 as they tried to figure out how to continue operations amid the IT outage. In Atlanta, Delta Airlines’ largest hub - around 20 early morning flights were canceled due to “technical issues”, with Delta Airlines resuming operations after two hours of pausing flights. 

When American Airlines issued their ground stop and canceled some flights, the airline directly named Crowdstrike as the cause for the delays.

Hours after the IT outage first began, airport delays remained across the U.S., with the average delay for both departing and arriving flights out of U.S. airports hovering around 70 minutes, per FlightRadar24 tracking data. 

In Australia, passengers arrived at airports for their JetStar flights only to find departure boards empty for the airline - JetStar canceled all flights for the remainder of the day. By early afternoon in Europe,  Turkish Airlines had already canceled 84 flights, with delays mounting. 

During the onset of the outage, KLM stated that flight handling was “currently impossible” and that due to this, the airline had to temporarily suspend operations. 

Delhi Airport Flights Boarding Manually

At DEL, airport staff took flights manually:

“In Delhi, there was very little information available when I arrived at the airport. No electronic terminals were available for check-in and the ones to speak with an agent were long and unwieldy. We were given blank boarding cards and asked to fill in the information manually. Baggage tags were printed blank, with passengers' information being entered manually by airport staff as well.” Samira Hussain, a BBC journalist who was at Delhi airport during the IT outage. 

Similarly in Europe, some airlines such as Iberia and Wizz began to conduct their check-in and airport operations manually. “Paper and pens in the age of AI” said a journalist when talking about his manual check-in experience for a flight out of London Luton Airport (LTN). 

“There are loads of delays, so even though our airline says their systems are not affected by the IT outage it seems like we might be here for a while” stated one journalist, Hannah Gelbart, after her flight was delayed at London Gatwick Airport (LGW) following the outage. 

According to experts, it may take days to undo the damage this IT outage has done. Billions of dollars in operating revenue have been lost, with the IT outage costing companies in nearly every industry millions of dollars. In the following days, the world will see just how much damage this IT outage has caused — and how to prevent such an issue again.