BA chief executive Alex Cruz says he will not resign and that flight disruption had nothing to do with cutting costs.
He told the BBC a power surge, had “only lasted a few minutes”, but the back-up system had not worked properly.
He said the IT failure was not due to technical staff being outsourced from the UK to India.
Mr Cruz said he was “profusely sorry” to the thousands of passengers still stranded at airports worldwide.
He said two thirds of passengers will have reached their destination by the end of the day.
A leaked staff email revealed Mr Cruz had told staff not to comment on the system failure. When asked about the email he told the BBC the tone was clear: “Stop moaning and come and help us”.
The airline is now close to full operational capacity after the problems resulted in mass flight cancellations at Heathrow and Gatwick over the bank holiday weekend.
So far on Monday, 13 short-haul flights at Heathrow have been cancelled.
Heathrow advised affected BA passengers not to travel to the airport unless their flights had been rebooked, or were scheduled to take off on Monday.
Passengers on cancelled flights have been told to use the BA website to rebook.
Until now, Mr Cruz had only posted videos on Twitter apologising for what he called a “horrible time for passengers”.
Source:BBC