A pair of A380 superjumbos owned by Qantas will resume flights again on Saturday, three weeks after the airline's entire fleet was grounded after an engine exploded mid-flight.A series of checks have convinced the Australian airline's chief executive Alan Joyce that the planes are safe to fly.Two of the six A380s powered by Rolls-Royce Trent 900 engines will take off at the weekend bound for to London via Singapore."We're completely comfortable with the operation of the aircraft," Joyce told reporters in Sydney Tuesday. "We believe it is appropriate to start the services this week."But A380s used for the Los Angeles to Sydney and Melbourne routes will remain grounded while further tests are carried out.An investigation into the engine explosion found the failure was confined to the specific component, which caused an oil fire and the release of the intermediate pressure turbine disc. Rolls-Royce has also reassured that the problem is specific to the Trent 900.