Qantas chief executive Alan Joyce has accused unions of ''blatant fearmongering'' for their claims about errors on the airline's aircraft sent for heavy maintenance in Asia over the years.

In his opening address to a Senate inquiry on Tuesday night, Mr Joyce said unions were running a line that the prospect of repealing a key part of the Qantas Sale Act would adversely affect safety.

''This is blatant fearmongering. It is playing the safety card as a tool of industrial relations,'' he told the Senate economic legislative committee.

In a bid to stop the government from relaxing the Qantas Sale Act, the Australian Licensed Aircraft Engineers Association last week released to a separate Senate inquiry a dossier detailing errors on Qantas planes following maintenance in Singapore, Hong Kong and Kuala Lumpur.

But Mr Joyce told senators on Tuesday night that they needed ''no reminder of the absolute Qantas commitment to safety'', emphasising that maintenance on its planes was approved by the Civil Aviation Safety Authority and done to the airline's high standards regardless of where it was carried out.