Cirrus SR22T: Abnormal Procedures for the Turbocharger
In the event of an unexplained loss of manifold pressure in an SR22T, the engine reverts to operating like a naturally aspirated engine. However, depending on the cause of the anomaly, this could be anything from a benign to a serious event. However, since it is not possible to accurately determine the exact cause, any such event should require an immediate diversion.
- Induction leak
This is on the “cold side” of the turbo (i.e with fresh air), and the intake air is leaking out before/after it is pressurized. This is typically not a significant hazard and the only consequence is that the engine reverts to performance of a naturally aspirated engine. Adjust flight profile as necessary and land as soon as possible. However, the next three possibilities on the “hot side” could pose more significant hazards.
- Exhaust leak
An exhaust leak prior to the turbocharger could result in an engine fire if the high-velocity and hot exhaust gases interacts with combustible components at any point.
- Wastegate failure
Wastegate is held closed by oil pressure. Loss of oil pressure would cause it to open, resulting in a loss of turbo performance. This could be a significant problem as the engine could get starved of oil. Monitor oil pressure.
- Turbocharger failure
The turbo is lubricated with oil, and so a failure here could also cause a loss of oil.
References
- https://itunes.apple.com/WebObjects/MZStore.woa/wa/viewBook?id=1072487639