The boss of British Airways has blamed a message filter accidentally left on after software testing and staff training as the root of the wide-spread problems when Heathrow Terminal 5 opened in March.

Giving evidence at a Commons Transport Select Committee Walsh told MPs that a messaging filter was being used during staff training to control the destination of messages, but ended up interrupting genuine messages being sent when the terminal opened. This created major baggage handling problems and resulted in the chaotic opening of the terminal.

Walsh said he regretted not postponing the launch.

Server capacity had also been inadequate, Walsh admitted, and needed to be increased almost two month after opening Terminal 5 to cope with the volume of messages.

The baggage system was designed by Vanderlande Industries in conjunction with IBM and Alstec. It is designed to handle up to 12,000 bags per hour.

BA had “compromised” on staff training, Walsh disclosed, to make sure the terminal opened in time. “We did this with our eyes open. We knew it was a risk”, he said.

Airport operator BAA chief executive Colin Matthews also admitted that there should have been more testing. But he said his company had yet to investigate who knew what and when.

According to BBC reports, Matthews said the baggage system had only been tested at full load 20 times and that “the testing regime did not adequately replicate the first days of operations”.

In the past few months, airport operators and IT suppliers have engaged in a blame game about the Terminal 5 fiasco.

Related stories: T5 systems not tested adequately, BAA boss admits to MPs