Twelve planes at airport gates at the time of the announcement had to return to disembark passengers. Another 64 planes in the air with 7000 passengers were continuing to their destinations. Those flights would be grounded after they touched down and passengers booked in to hotels.
The airline expects about 13,000 passengers to be affected by 7pm tonight. The grounding stranded 17 leaders of delegations to the Commonwealth Heads of Government Meeting in Perth.
The move drew a quick reaction from Prime Minister Julia Gillard, who said she would use a controversial employment law to force a quick end to the industrial action.
Kiwi couple David Erkell and Rebecca Jarmin, who live in California, were on the flight from Los Angeles, which was about to take off.
Jarmin, 38, said: "We had sat down and were buckled in when the captain said he had just had a call from Sydney and the chief executive of Qantas had grounded all flights."
Passengers on the plane remained calm, "probably because we were all Kiwis and Aussies".
She said the plane returned to the departure gate where passengers disembarked and returned through Customs. As she spoke to the Herald on Sunday, she was waiting with other passengers outside the airport for charter buses to a hotel arranged by the airline.
Jarmin, from West Auckland, said she and her husband, aged 45, were returning home for her brother Tim's wedding next weekend on Waiheke Island.
Uncertainty about the Qantas flight meant they booked new flights with Air New Zealand tonight, she said.
The grounding is estimated to cost the airline about $20 million a day. As well as hotel accommodation, the airline will also offer alternative flights to those who can't get home.
Refunds and ticket transfers will also be available.
