Multiple Qantas flights at Whyalla and Port Lincoln airports were affected last week, with eight flights cancelled and several others delayed over a four day period.
Passengers expressed frustration, citing lost wages and missed appointments.
Qantas attributed the disruptions to unscheduled maintenance, requiring parts to be flown in.
Passengers were accommodated on the next available flights, and the issue was resolved by July 12.
It was similar for the Adelaide to Whyalla route, with flights generally leaving around two hours after their scheduled take-off times in the morning, and a long delay of seven and a half hours for passengers flying on July 12.
Qantas is now the only airline serving Whyalla after Rex’s exit.
The Whyalla City Council contacted Qantas to express concerns, and the airline explained the engineering issues causing the disruptions.
All three affected aircraft are now serviceable.