TIO-540 Turbocharger Question

[Ian J]

You have a Piper Navajo with TIO-540 engines. Once takeoff power is applied, one engine maxes out at 49" MAP as normal, the other maxes out at 59". What happened?

I'm pretty sure the reason would be that the density controller has failed, since the density controller limits maximum MAP by regulating bleed oil if the density becomes excessive.

Over-boost may also be controlled by an over-boost control valve though, and I have no idea if the TIO-540s have that.

In an over-boost condition, is it acceptable to bring the throttle back on the affected engine and simply match up the MAPs for the duration of the flight?

[USMCmech]

The waste gate controller failed on the 59" engine.

At 59" the overpressure valve opens and dumps some of the pressure to save the intake mannifold.



Yes you could throttle back that engine and limp toward an airport to get it fixed, but you should not take off again.

I MIGHT limp home to a maintence base if it wasn't far away, but you deffinately can't fly the rest of your run.

[Ian J]

Thanks! So say you are given this situation by a check airmen who says it's okay to throttle back and keep on flying - what could I tell him specifically to let him know that this is a bad idea?

[USMCmech]

How many properly functioning turbo chargers are required for dispatch acording to your MEL?

I'm willing to bet it's one per engine.

End of discussion.

[Ian J]

You're right. That's the simplest way to go.

[Screaming_Emu]

Originally Posted by Ian J

Thanks! So say you are given this situation by a check airmen who says it's okay to throttle back and keep on flying - what could I tell him specifically to let him know that this is a bad idea?

I think the best way is "ummm, ok. I'm getting out, but its all you man!"