Something for your aircraft model buffs

[HawkerDriver]

Originally Posted by Falcondvr

Yes on theGarrett's, but what is the answer to Hawker's question on the King Air PT-6 engine???

The pt6 is not the same bowing issue as it's a different assembly. However I don't remember much about the pratt. just "cooling" was all i was told for the pt6, but I'd like to know a more exact answer.

[Falcondvr]

Originally Posted by HawkerDriver

The pt6 is not the same bowing issue as it's a different assembly. However I don't remember much about the pratt. just "cooling" was all i was told for the pt6, but I'd like to know a more exact answer.

Ok, thanks. I know about the "beta tube" bowing on the -10 garretts I used to fly (many moons ago). I just did not remember ever having to spin the props on the King Air I flew (again many moons ago).

[skysurfer2010]

Originally Posted by Falcondvr

Ok, thanks. I know about the "beta tube" bowing on the -10 garretts I used to fly (many moons ago). I just did not remember ever having to spin the props on the King Air I flew (again many moons ago).

I think a lot of it has to do with myth. Like I sated, it's more important on new or freshly overhauled engines. Our company has flown the two B100s for over 20,000 hours and it's not company policy to spin them. We only spin the cans if the temps are above 300 on shutdown or above 200 for start up (pretty rare except those hot summer days). They've been extremely reliable over the past 30 years so I'd assume our company is doing something right. Or maybe this is just true for the King Airs due to better cooling?

[PrettyFlyCFI]

Although the model airplane is a KingAir, I'm sure the engines aren't exact scale replicas of PT-6s. I can't help but wonder if those model engines have a single shaft not unlike the TPEs.

[Falcondvr]

Originally Posted by skysurfer2010

I think a lot of it has to do with myth. Like I sated, it's more important on new or freshly overhauled engines. Our company has flown the two B100s for over 20,000 hours and it's not company policy to spin them. We only spin the cans if the temps are above 300 on shutdown or above 200 for start up (pretty rare except those hot summer days). They've been extremely reliable over the past 30 years so I'd assume our company is doing something right. Or maybe this is just true for the King Airs due to better cooling?

Welp, on the MU2 engines, the beta tube would bow until the metal cooled enough where it "unbowed". What I was taught was if I had a 30min or less turn around, I needed to turn the props until it started binding and stop. I would continue this procedure until the props turned freely. I could then start engines. Anything more than 30min, the procedure would not be required.

Guess that is not the case on your B100