Random events may now occur during a maintenance check. The probability of an event occurring is linked to the number of cycles on the airframe. The more cycles an aircraft has, the higher the chance that an event will occur.
If an event does occur, there are 5 levels, each with different time and cost adders:
Level 1: 40% chance, adds 1-6 hours & 10%-50% of an A Check cost
Level 2: 30% chance, adds 6-12 hours & 50%-100% of an A Check cost
Level 3: 15% chance, adds 12-48 hours & 50%-100% of a B Check cost
Level 4: 7%-15% chance, adds 2-7 days & 50%-100% of a C Check cost
Level 5: 0%-8% chance, adds 14-30 days & 50%-150% of a D Check cost
Level 5 events are reserved for particularly rare aircraft with low parts availability. More common aircraft have a much lesser chance of encountering a level 5 event.