The body in charge of Britain's air traffic control system was warned four months ago that it was ill equipped to deal any technical faults, it has been claimed.
A report in the UK's Independent on Sunday says the Civil Aviation Authority told NATS officials in the summer that they needed to be better prepared to deal with IT problems.
A computer glitch at NATS control centre in Hampshire on Friday led more than 300 flights being cancelled or delayed and travel disruption for thousands of passengers.
The air traffic control organisation said on Saturday that the computer meltdown was sparked by an unprecedented systems failure.
It was the second major problem to hit the Swanwick centre in just over a year.
The paper also said that experts had warned NATS that a huge redundancy programme might deepen the problem, resulting in serious future meltdowns.
Meanwhile, an MP called for the top boss of NATS to lose his bonuses as a result of the failure.
Richard Deakin, NATS chief executive, said the software glitch was "buried" among millions of lines of code written a quarter of a century ago.
But Labour MP Paul Flynn told The Sunday Times that Mr Deakin earns more than stg£1m after receiving a 45% pay rise this year.
"I hope after the chaos, which was dreadful, though a rare event, he will have his bonuses stripped from him," he said.
NATS said operations were back to normal on Saturday with only minor delays and cancellations at some of the UK's airports as a result of a backlog.
A statement from NATS said: "Swanwick controller workstations provide a number of tools and services to the controller to enable them to safely control a high volume of air traffic."
"In normal operations the number of workstations in use versus in standby fluctuates with the demands of the traffic being controlled."
"In this instance a transition between the two states caused a failure in the system which has not been seen before. The failure meant that the controllers were unable to access all of the data regarding individual flight plans which significantly increases their workload."
"We immediately took steps to reduce the traffic into and out of the UK network. At no time was safety compromised in any way."
Mr Deakin said NATS is investing a "huge amount" in new technology, with stg£575m set to be spent over the next five years to move towards more resilient, internet-based systems.
