Tpe331

[JohnnyP]

(wasn't sure which forum to dump this one in)...

Have never operated a direct-drive turboprop before.

For a guy only used to pt6's, PW120's, etc, what are some of the major operational differences compared to a TPE331?

I don't currently have any manuals at this time, and searching on the internet makes it hard to come up with some basic operation/tech info.

(found a few articles on shaft bow, spinning the props, summertime cooling tips, etc, but would like a bit more)

Any info from you guys will be much appreciated!

 

[propsarebest]

-They are REAL easy to torch on startup, especially the older ones

-BRING YOUR EAR PLUGS, cause you will be deaf.

-They eat batteries on startup like Star Jones locked in a See's candy store. We always started them up off of a GPU.

Ohh, and they were designed to be disposable- just throw them away when they time out.

 

[JohnnyP]

.....

Thanks for the info.

I was also browsing the turbo commander website and found some general articles on TPE331 operation, would like to run across some more.

The way I understand it, the RPM on, lets say ground idle, is around 100%...(what would the actual RPM be, 2000?) ......hence the noise?

 

[Launchpad]

You'll find that most people hate them, usually just because.

They are waaay better on fuel, they have a waaay higher TBO, and they have a quieter noise foot print in the air. On the ground, that's another story.

The noise comes from the compressor blades in the front from a direct view is the worst. Louder than a Pratt for sure.

There is a ground idle, so they are not at 100% all the time. Prop not at 2000, probably upper teens but depends on A/C and power output.. (noise comes from blade length, and blade length is usually based on power output)

I ran them on a jetstream for years, thought they were great.

 

[AV80R]

(wasn't sure which forum to dump this one in)...
Have never operated a direct-drive turboprop before.
For a guy only used to pt6's, PW120's, etc, what are some of the major operational differences compared to a TPE331?
I don't currently have any manuals at this time, and searching on the internet makes it hard to come up with some basic operation/tech info.
(found a few articles on shaft bow, spinning the props, summertime cooling tips, etc, but would like a bit more)
Any info from you guys will be much appreciated!

Well, got some 4,000 hours plus in the TPE 331-12 (Jetstreams).
- We usually used GPU power to crank it up but internal battery start was not that big of a deal.
- True, they are loud.
- At the gate, don't forget to spin a few times to avoid thermal bending (I think that's the proper term?) I believe it was more important for the -10 and below engines bt we did that too.
- Most people hate them? Huh? Not me or anyone I knew. I loved those things, loud but built to last!

 

[JohnnyP]

....

How is the start procedure, as compared to a PT6 or PW120?

 

[phr8dawg]

I think the right term is shaft bow where you spin the prop to where the binding is strongest and let it cool down in that position. TPE331s make a snarling sound in beta range which sounds better
than a wound-up Harley. I liked the plant!

 

[Tgaug6300]

Starting is much easier than the Pratts. I can only speak of the Turbo Commanders, but on that airplane it was just turn the switch to "Ground Start" everything was automatic from there. Once that engine was stabilized start the other one.
Power is instantaneous too, no spool up time (nice on go-arounds). I think I read somewhere where the TBO on the TPE-331 series has been bumped up to 5400 hours. Great engines though! Unfortunantly it is getting harder to find a mechanic that knows what it is.
I never met anyone that has operated them that did not like them.

 

[JohnnyP]

....

I think i read somewhere last night about an upgrade taking it to 7000hrs+ on the TBO..?..

 

[APFPilot]

I think i read somewhere last night about an upgrade taking it to 7000hrs+ on the TBO..?..

I haven't heard 7000, but 5400 can be done on the Twin Commanders. I have a bunch of 331 information in my office. If you want to send me a PM I may be able to help you.

 

[JohnnyP]

....

I haven't heard 7000, but 5400 can be done on the Twin Commanders. I have a bunch of 331 information in my office. If you want to send me a PM I may be able to help you.

I went and checked again, and your right, 5400 is it. Not sure where I came up with 7000, must have been the wine.

PM sent.

 

[400A]

Only real Gotcha I knew of was to be very vigilant with lip/intake heats and ignitions in icing. It is easier to flame-out than the Pratts. ( Research the Hooters Merlin/Fairchild 300 crash) The older ones in the Merlin were harder to start because you had to sit and pump a primer button to keep the start accelerating at the proper rate. I liked the pratt's better, but never had a problem with the 331's.

 

[siouxicide]

I have experience with both and I'd have to same I'm a Garrett fan for one simple reason: Besides start, you can't screw up and break a TPE-331 under normal ops. Firewall it and forget it if you want to(with the SRL in the SA-227, not sure about other 331's). With the PT6 the starts are faster and cooler(as in cold) but you really have to babysit the torque in-flight. The TPE-331-11U only seemed to want to exceed max torque on TO in frigid temps...or with the CAWI on.
Agree with the GPU use mentioned. Good batteries did a better job though, but do that enough and you won't have good batteries anymore. Spinning the props after shutdown. Not having condition levers. Airflow front to back. CHECK OIL THROUGH SIGHTGLASS!!! God I hate pulling a dipstick on a PT6. Push a button to start and watch it go. Flames out the tailpipe if you do it right. No autofeather, but the NTS is kinda nice to have. Bout all I can think of.

 

[JohnnyP]

.......

All good stuff guys, much appreciated!

 

[Say Again Over]

A great engine, treat it like a turbo charged recip, give it a good three minutes for cool down, if you are in a steep descent and one or both of the props start cycling toward feather, don't worry too much it's just a slightly low FF setting. Like previously posted, keep your battery in top shape or use a GPU, recommend trend monitoring.

 

[AV80R]

...I think the right term is shaft bow where you spin the prop to where the binding is strongest and let it cool down in that position...

That's it, I knew there was a better term for it.
As far a starting procedure?
Well,
push "Select"
push "Start" (For airstarts the “Start button will not illuminate, or was it the Select button?)
...I think that's about it? - Fully automated starts.
We had the TPE 331-12s on our birds. I can also vouch for the airplane's single engine performance - it's a really great engine!

 

[Box-Hauler]

The Pratt / Garrett argument is like the ford/chevy issue. I personally loved the Garrett on the metro, J31, and J41. yes it was a little noisy on the ground but it had a good fuel consumption, lasted long time, the NTS was a cool system and you could choose to fly at 97 or 100% prop speed, depending on how fast you wanted to get there.

 

[GIVDrvr]

Loved the Garretts on the MU2. Honeywell used run an annual TP seminar which was very good go to it if you can. I believe we had the 7000 hr extension. We used to also spin the props by hand a few turns after shutdown to enhance cooldown.