Galesburg IL?  You mean the Stearman fly-in?  Haven't been.  Is it worth going?

The only single-spool engine I'm familiar with in a turboprop configuration is the Garrett TPE 331.  On a Turbo Commander no less.  Hard starting, ear piercing, screaming SOB.  Better hope the battery is 100%.  If not, bet bucks on a hung start while you burn up most of the battery getting that prop turning.   

Otherwise, a pretty solid engine. 

It's worth it if you love old planes.  I flew with the New Orleans Stearman crew for a lot of years.  Went to GBurg twice.  One year had 125 Stearmans on field.

I spent a lot of time around aero engines, the only turbine that I lived with for an extended period was the Lycoming 101 on the HH-65.  Ditto on the battery.
650 hp engine stretched to 750 hp on the H65.  60 hour interval PT dye pen inspections.  To get a one engine hover out of the aircraft, there was a one engine inop switch that you hit when you were down to transition speed entering a hover.  It kicked a cam on the top end throttle stop to a notch so you could go above normal power.  Which meant if you had a heavy handed pilot in a hover, you overtorqued the gearbox.  If you lost an engine, you would throw away the one that got you home since the hot section would be cooked.  Not a pretty solid engine.  All the air ambulances running BK-117s had these engines with the same problems at 650 hp.

Why didn't all these people quit messing around and just mount PT-6s.

Interesting...  I'll have to check it out.  I went to the Waco fly-in at Creve Coeur airport near STL year before last.  One big coffee klotch. 

The TPE 331's on the Commander were rated at about 650 SHP as I recall, but were uprated to as much as 1,200 HP.  Their main problem was the bull gear engaging the high-speed pinion of the common shaft.  Several reports of metal fatigue causing the bull gear to split into multiple pieces.  I believe that problem was solved with a new bull gear.

The PT-6 is the solution though.  Spent some time with -60's on on a King Air 300.  Pratt and Whitney makes a good product.

Everyone else:  Isn't this stuff just priceless?  It's hard to get this kind of quality banter anymore.

"Yeah, I ran a 12,000 HP JBE-1532 Turboproposhaft.  Single spool, of course.  I only run single spools, or else you'll burn your battery and then, you know, if the pump goes out, you're stuck with an unstart and a hung shaft, and then, well, everything goes to crap.  And don't get me started on the dye pen inspections."

Quote from: aaronstj on March 08, 2006, 11:57:59 AM
Everyone else:  Isn't this stuff just priceless?  It's hard to get this kind of quality banter anymore.

"Yeah, I ran a 12,000 HP JBE-1532 Turboproposhaft.  Single spool, of course.  I only run single spools, or else you'll burn your battery and then, you know, if the pump goes out, you're stuck with an unstart and a hung shaft, and then, well, everything goes to crap.  And don't get me started on the dye pen inspections."

Hahahahahahahahahaha. I was just thinking something similar to that. More along the lines of, "Wow, I have no idea wtf happened to this thread. I think I'll stay out, but still look on in shock and awe at whatever it is those two are talking about."

If you live long enough, you accumulate a wealth of useless knowledge that only has meaning to a small and select group of people.
Kind of like knowing the jetting numbers to a DJ St3 kit.

Meanwhile back at the ranch.
GeeP,
Garrett must have had a problem with gear boxes.  The TFE731 had the GG based on an APU and they hung the fan on a planetary gear box.  McDermott had a couple of Falcon 10s, one of which had the planet bearings on each engine shell on separate flights 3 hrs apart.  Engine failure on 2 consecutive flights.  The solution was a bellville spring on each planet bearing for preload.  Problem went away on a high performance jet with the installation of what would normally be $5 in parts.  I don't know how they beat the power out of the 331, at least the PT-6 had specific upgrades through the power range.  I guess the big swearingen merlin commuters were still running 331s.

aaron, that 12,000 hp JBE, are you sure that you didn't mean the 15,000 counterrotating tprop on the Bear, it was also single shaft.  Oh yeah, and don't get me started on dye pen inspections.

Alpha, I thought this thread was on track.  Besides you're a fellow Texan, where is the love?

Quote from: Codger on March 09, 2006, 06:55:42 PM
Alpha, I thought this thread was on track.  Besides you're a fellow Texan, where is the love?

Hey man, I'm not ragging. I think it's awesome y'all know so much about this stuff.

Quote from: Codger on March 09, 2006, 06:55:42 PM
aaron, that 12,000 hp JBE, are you sure that you didn't mean the 15,000 counterrotating tprop on the Bear, it was also single shaft.  Oh yeah, and don't get me started on dye pen inspections.

Yeah, that was it.   

Also, reminds me of a Monty Python sketch I like

Quote from: Squadron LeaderTop-hole.  Bally Jerry, pranged his kite right in the how's-your-father; hairy blighter, dicky-birded, feathered back on his sammy, took a waspy, flipped over on his Betty Harpers and caught his can in the Bertie.[/quote;

Aaron hit one key point.
How can you be impressed with the information if you aren't positive about the source.

Good point!   

I recall that they changed the pressure angle and material of the gearset to solve the problem.  Apparantly, the bull gear had very high root loading which was causing small cracks to appear in the face of the gear.  Pie sections of the bull gear were separating and causing all kinds of fun problems.

Once the section separated, it would punch a hole in the bottom of the gearcase and dump all the reduction gear lubrication into the engine intake.  Naturally, the oil would go right through the bleed air line and smoke up the cabin!  That's part of the reason why I prefer aircraft with cabin superchargers.  

Dye penetrant isn't too bad!  Magna mess isn't any fun though.

Re: the $5 solution.  That reminds me of lots of AD's.  Especially flight manual supplements.

I spent too much time rotor head and open cockpit, we didn't worry to much about pressurization.  Superchargers belong on engines.   
You get the entire simulator disaster scenario live.  Vibes in the airframe, total loss of one engine, smoke in the cabin. 
Did it take out the feather ability?

We did worry about things like shedding engine gearboxes in helos since the firewall was over the flight mechanics head.
We surged a compressor in hover once.  I just about surged something myself.  The centrifugal stage coughed and blew some blades off the entry axial compressor.  Fortunately on the helos there was an entry screen on the engine to keep foreign objects out.  It also works well in reverse.  It retained the blades so when the surge cleared, the blades sucked back through the engine.  We found scars all the way to the PT.

That sounds like a pretty elementary mistake to make on a flight engine.  I understand finding out heat transfer and flow problems on a hot section, but gear mechanics are a pretty mature subject. 

The dye pen itself wasn't as bad as the fact that you had to do it with the firewall cutting into your ribs or the tail rotor shaft bearing jammed up your backside.