Grounded Australian budget carrier Tiger Airways faced another three weeks on the tarmac Wednesday after aviation regulators said they would seek a court-enforced flight ban until August. Tiger was barred from operating domestic flights last Saturday for a week by Australian regulators over \"serious and imminent\" safety risks relating to pilot training, fatigue management and other issues. The Civil Aviation Safety Authority (CASA) said it would apply to the Federal Court of Australia to extend the ban until August 1 giving it more time to probe the risks and carrier\'s response. \"CASA is making the application to the court because investigations into Tiger Airways Australia will not be completed by the end of the initial five working day suspension period,\" CASA said late Wednesday. If work finished before that time and CASA was satisfied the dangers had eased it \"may be possible\" for Tiger to return to the skies earlier, the regulator said. \"The suspension of Tiger Airways Australia’s operations remains in place at until either the Federal Court refuses CASA’s application or CASA withdraws it,\" it added. In a short statement issued late Wednesday the airline said its chief executive Crawford Rix would step down following the regulator\'s move, the Australian Associated Press news agency reported. The Australian arm of Singapore\'s Tiger Airways had halted ticket sales earlier Wednesday after the consumer watchdog questioned its ability to deliver flights amid ongoing uncertainty over how long the ban would last. Australian Competition and Consumer Commission (ACCC) chief Graeme Samuel was tight-lipped on whether he was considering legal action against Tiger after it continued to sell tickets for next week in defiance of his warnings. Samuel said Tiger continued to sell flights until late Tuesday for next week without caveats -- the earliest just hours after the ban expires -- despite having no certainty that it would be allowed to fly. \"We had said publicly that they could continue to sell tickets only so long as they had a reasonable expectation of being able to provide the flights that they were selling tickets for,\" Samuel told AFP. \"It\'s a pretty simple proposition. If you don\'t think you can supply the flights then you shouldn\'t be selling the tickets.\" Samuel would not be drawn on whether the ACCC believed Tiger had breached trade laws, for which it could be fined more than Aus$1.1 million (US$1.17 million), saying only that they were in \"continual and constant communication\". \"I won\'t say any more than that, but suffice to say we\'re not just going to sit back and wait and see how things transpire,\" Samuel said. \"I frankly was bewildered that they seemed to be ignoring the advice and the exhortations that I was giving them and other regulators were giving them, both in public and in private,\" he added. \"It didn\'t seem to me, if I could venture the opinion, to be terribly good business practice to be selling tickets without at least saying to customers \'look, you ought to be aware if you are buying these tickets there is a risk that we may not be able to provide the flights and we may have to cancel\'.\" Samuel said it was not enough for Tiger to offer cash back if customers were unable to fly next week because their refund process was so slow, in some cases \"several months\", leaving people out of pocket and scrambling for new tickets. Tiger has estimated that the ban is costing it US$1.6 million a week and has thrown the travel plans of some 35,000 people into disarray. It was threatened with suspension earlier this year after failing to address issues of pilot proficiency, training and checking, and fatigue management. It is the first grounding of an entire airline due to safety issues in Australia\'s history.