Thomson Airways has completed several successful test flights today.
The airline has flown six aircraft to the UK from Iceland, where they had previously been diverted due to the volcanic ash disruption.
Two Airbus A320S and three Boeing 757s arrived at Prestwick airport, and one Boeing 757 arrived at Manchester airport this morning.
The airline said no technical difficulties were experienced during the flights and there was no damage to any of the aircraft.
The aircraft have now been given approval to continue further testing.
The intention is for two aircraft to fly from Prestwick to Manchester and three to fly from Prestwick to Luton later today.
The aircraft will be flying at a lower altitude than normal because they will be entering restricted UK airspace.
Director of engineering Fraser Ellacott said: “The safety of our customers and crew is our number one priority at all times.
“We are sharing this information with our sister airlines in the Tui Travel group and the wider aviation industry with the intention of assisting the authorities during their review of the flight restrictions currently in place.”