US senators have sent letters to major airlines expressing concerns over IT vulnerabilities.
It was prompted by two recent outages which caused widespread disruption for Delta passengers and Southwest Airlines.
In the letter, Democratic senators Richard Blumenthal and Edward Markey said: "We are concerned with recent reports indicating that airlines’ IT systems may be susceptible to faltering because of the way they are designed and have been maintained.
"Now that four air carriers control approximately 85 percent of domestic capacity, all it takes is one airline to experience an outage and thousands of passengers could be stranded."
Delta’s IT meltdown last week caused the cancellation of more than 3,000 flights despite the outage lasting just six hours.
Southwest Airlines, which lost millions of dollars after a faulty router grounded more than 2,000 flights in July, said it had spent ‘significant effort and financial investment to ensure the technology that supports our business and our operation has back-up and recovery capabilities’.
The Senators asked the airlines for comments to a number of questions posed, relating to current initiatives to modernise IT systems and details on their back-up systems, and their policy on rebooking and compensation in the event of a major system-wide outage.
