More airline outages as carriers grapple with ageing technology

Airlines will likely suffer more disruptions like the one that grounded about 2,000 Delta flights this week because major carriers have not invested enough to overhaul reservations systems based on technology dating to the 1960s, airline industry and technology experts told Reuters.

Airlines have spent heavily to introduce new features such as automated check-in kiosks, real-time luggage tracking and slick mobile apps. But they have avoided the steep cost of rebuilding their reservations systems from the ground up, former airline executives said.

Scott Nason, former chief information officer at American Airlines Group, said long-term investments in computer technology were a tough sell when he worked there.

"Most airlines were on the verge of going out of business for many years, so investment of any kind had to have short pay-back periods," said Nason, who left American in 2009 and is now an independent consultant.

The reservations systems of the biggest carriers mostly run on a specialised IBM operating system known as Transaction Processing Facility, or TPF. It was designed in the 1960s to process large numbers of transactions quickly and is still updated by IBM, which did a major rewrite of the operating system about a decade ago.

A host of special features, ranging from mobile check-ins to seat selection and cabin upgrades, are built on top of the TPF core, or connected to it.

"They have surrounded that old industry infrastructure with modern technology," said Bob Edwards, United Continental Holdings' former chief information officer until 2014. "Those systems have to always reach back into the old core technologies to retrieve a reservation or to figure out who flies between Dallas and New York City."

When a power outage shuts off that reservations system - as happened on Monday to Delta Air Lines' "Deltamatic" system - TPF falls out of sync with the newer technologies that passenger service agents use to assist travellers, Edwards said.

Airlines are then forced to cancel flights as demands from stranded customers flood their employees - who meanwhile are handling bookings on an older platform without their familiar, modern tools, he said.

Several years ago, it took United six hours to recover from a test shutdown, thanks to complications with the many add-ons built atop TPF, Edwards said.

Other recent disruptions include one in July that prompted Southwest Airlines to cancel over 2,000 flights and two outages last summer at United Continental.

IBM Senior Vice President Tom Rosamilia said in a statement that TPF "was not named as the source or issue in any of the recent outages" and that it "is one of the most modern and reliable systems in the airline infrastructure."