04/26/21
Message Overview:
Message Name:
BLACK DUST (SUET) AROUND ENGINE GENERATOR EXHAUST
| Identifier: | 243OBS003 |
| Effectivity: | 20501 - 20999 |
| System: | Electrical |
| Associated CAS: | L GEN FAIL (Caution) R GEN FAIL (Caution) |
| System Description: | 24-31-00 |
| Schematic Diagram: | 24-31-00 |
| Wiring Diagram: | 24-31-05 24-31-07 |
Message Description:
Black dust accumulation is observed on the nacelle's lower cowling, around the engine generator exhaust port. Known and often reported by the maintenance as black sooth .
The black sooth is from generator's rotor rubbing onto the stator due to a worn rear bearing.
Most likely, there will be no CAS message posted. This observation is a sign of a degrading generator.
Possible Causes:
- Main Generator (G1)
- Main Generator (G2)
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Cleaning of the External Surfaces of the Aircraft | AMM 12-21-00-101-808 |
| Removal of the Main Generator | AMM 24-31-05-000-801 |
| Installation of the Main Generator | AMM 24-31-05-400-801 |
Troubleshooting Recommendations:
- Replace degrading Main Generator (G1 or G2).
- Remove the black dust around the Engine Generator Exhaust port as per AMM (cleaning of the external surfaces of the aircraft).
- Do close out.