AIRBUS A220
Bordeaux, OF — February 12, 2020
Event Information
| Date | February 12, 2020 |
| Event Type | INC |
| NTSB Number | ENG20LA015 |
| Event ID | 20200212X95117 |
| Location | Bordeaux, OF |
| Country | FR |
| Coordinates | 44.83077, -0.57770 |
| Highest Injury | NONE |
Aircraft
| Make | AIRBUS |
| Model | A220 |
| Category | AIR |
| FAR Part | NUSC |
Conditions
| Light Condition | DAYL |
| Weather | Unk |
Injuries
| Fatal | 0 |
| Serious | 0 |
| Minor | 0 |
| None | 154 |
| Total Injured | 0 |
Event Location
Probable Cause
A No. 1 (left) engine low pressure compressor (LPC) stage 1 integrally bladed rotor (IBR) separation due to a high cycle fatigue crack (HCF) that originated at the runout of an airfoil leading edge root radius. The HCF crack developed because of a mechanically coupled LPC stage 3 and stage 1 IBR mode excitation and blade flutter response. The excitation was driven by an acoustic tone generated by turbulent airflow passing over the 2.5 bleed valve duct cavity while the engine was operating at high speeds in specific flight conditions. A primary contributor to the failure mode was an electronic engine control (EEC) software update that changed the LPC vane schedule and increased the likelihood of LPC stage 1 IBR blade flutter onset within the engine operating range.
About This NTSB Record
This aviation event was investigated by the National Transportation Safety Board (NTSB). NTSB investigates all U.S. civil aviation accidents to determine probable cause and issue safety recommendations to prevent future accidents.