The Boeing (BA.N) 747 landed safely in Melbourne on Monday morning after a flight from Los Angeles but was immediately grounded. The first officer noticed the cracks during the flight, a spokesman said.
The windscreen was to be replaced and the plane was expected to leave for the United States again early on Tuesday.
It is the latest of a series of recent technical mishaps involving Qantas. Last week one of the airline's Airbus (EAD.PA) A380 aircraft was grounded after two tyres exploded on landing in Sydney. [ID:nSGE6300AT] (Editing by Lincoln Feast)