| LEVEL | DESCRIPTOR | SEVERITY DESCRIPTION* |
| 1 | Insignificant | No significance to aircraft related operational safety. |
| 2 | Minor | Degrade or affect normal aircraft operational procedures or performances. |
| 3 | Moderate | Partial loss of significant/major aircraft system or result in abnormal F/Ops procedure application. |
| 4 | Major | Complete failure of significant/major aircraft system or result in emergency F/Ops procedure application. |
| 5 | Catastrophic | Loss of aircraft or lives. |