A spokesman said that the planes, previously registered as G-ETAC and G-OAUR, were sold in the space of a fortnight at the end of September.
The airline decided to switch to Twin Otters after the States of Guernsey cut its financial support for the public service obligation to operate the Alderney route. It had cost the airline £3m. a year to run the Dorniers.
The first Twin Otter started flying the Alderney route, in partnership with Isles of Scilly Skybus, on 1 November last year.
Although there is still criticism of reliability from Alderney residents, the States Trading Supervisory Board said in August that the reliability on the route had improved since the Twin Otters were brought in – despite one Alderney States member claiming that the figures had been ‘spun’.
The Aurigny spokesman said the airline thanked all of its team members involved in preparing the Dorniers for sale and all who had supported the aircraft during their years of service.