1. Maintenance work performed unexpectedly on equipment or systems due to failure, breakdown, or emergency conditions, rather than according to a predetermined schedule
The server required unscheduled maintenance after the unexpected hardware failure.
O servidor precisou de manutenção não programada após a falha inesperada do hardware.
2. Corrective or emergency repairs undertaken immediately to restore functionality and prevent further damage
The airline had to perform unscheduled maintenance on the aircraft before it could resume flights.
A companhia aérea teve de realizar manutenção não programada na aeronave antes de poder retomar os voos.