Passengers booked on a Cathay Pacific flight from Sydney yesterday arrived in Hong Kong hours behind schedule after a delay the airline blamed on an aircraft computer problem rather than pilots' industrial action. The airline's pilots stepped up their longstanding work-to-rule campaign this week, but Cathay said 'human-related' factors did not contribute to the extended delay. Flight CX 100, due to land at 10.30pm on Monday, touched down at 8.37 last night with only crew on board. Passengers had been transferred to other flights which arrived earlier in the day. They were put up in hotels in Sydney while the computer problem was fixed, a Cathay spokeswoman said. Seventy-eight per cent of 111 Cathay flights yesterday departed within 15 minutes of schedule, in line with normal operational standards, she said. Two flights experienced delays of more than an hour, both for 'technical' reasons. 'Yes, we have some delays but not really caused by human factors . . . so far so good,' the spokeswoman said. 'We can assure [customers] that our operations so far are normal.' Cathay's punctuality was usually in line with world benchmarks of an average of 80-85 per cent of flights leaving within 15 minutes of schedule, she said. General secretary of the Aircrew Officers' Association, John Findlay, said he expected the effect of the second phase of the industrial campaign to intensify over coming days as more pilots became familiar with the instructions. 'We have issued our next step and will just carry on . . . we're telling the flying public the dispute is not finished,' he said. Asked what sanctions would await members who did not obey the new compulsory union safety measures, Mr Findlay said any instances would be judged on a case-by-case basis. 'The ultimate sanction is expulsion from the union,' he said, adding that suspension was another alternative. However, he was not aware of any problem with members failing to carry out the work-to-rule so far.