More than 3,000 passengers were affected on Sunday when Air New Zealand grounded its fleet of ATR aircraft following the discovery of hairline cracks in one plane.
The cracks were found around the cockpit window during a routine maintenance inspection on a plane operated on domestic routes by Air New Zealand subsidiary Mount Cook, Xinhua reporetd citing Radio New Zealand.
Air New Zealand cancelled all ATR flights on Sunday, saying alternative travel arrangements were being put in place.
Two ATR planes, however, returned to service later in the day between Christchurch and Rotorua, and Auckland and Palmerston North.
The 68-seat ATR aircraft has an average age of about 11 years.