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Dave Siciliano (ADS)
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Posts: 8469
Loc: ADS (Dallas, TX)
Turbine P-Baron
      #190655 - 03/29/08 02:09 PM

The folks at Rocket Engineering have been working on converting a P-Baron to a twin turbine with -21 (PT-6s). Sent me some info and it looks impressive on paper. They claim a rate of climb as fast as 5,000 fpm and high speed cruise at FL250 over over 300 knots. If anyone would like to see what they sent me, send me a private message with your e-mail address and I'll forward a copy.

They are supposed to be test flying the first one in a couple weeks and I'm told the folks from Twin & Turbine will do a demo flight with them soon.

Best,

Dave


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Tony Williams [MYF]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201551 - 06/15/08 01:19 AM

Is that the P-Baron that's sitting at Carlsbad, CA ?

--------------------
Tailwinds always,

Tony Williams


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Jeff Hartmann CIC
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201572 - 06/15/08 09:11 AM

Dave,

I assumed they are using their Duke package, when I google Rocket Engineering I got more hits with you in them than the owner of the company. You should get a discount for marketing!

(side note) Tony, you moved to the 120 from the CRJ..?
It'll build up your arms..<G>

--------------------
Jeff

nothing clever to say right now...


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Jeff Hartmann CIC]
      #201577 - 06/15/08 09:49 AM

Quote:

Dave,

I assumed they are using their Duke package, when I google Rocket Engineering I got more hits with you in them than the owner of the company. You should get a discount for marketing!

(side note) Tony, you moved to the 120 from the CRJ..?
It'll build up your arms..<G>




I certainly did circulate their material, but like to think I tempered it with a third party view to some extent <g>

Like all paper planes, it looks good. Of course, there are some things one should know. I need to e-mail them again and get an update, but they were trying to move the top of the green arc up to 206 to 207 knots so the plane could legally cruise near 300 TAS at FL250. I spoke with someone on a standards committee that offered that might be difficult. If Rocket doesn't get that, high speed cruise would certainly be slower. Of course, high speed cruise is more to show off. Long range cruise would be more practical.

They've had a couple issues that the Duke guys are waiting to have addressed. Any time one goes to a boutique with a STC, they have to wonder about service after the sale. Rocket has a great reputation, but servicing a small number of conversions might not get top priority. Then, one would have to get the plane back up to Washington. They've raised the price from what I was first told.

Anyway, for someone like me with a nice P-Baron, it's interesting. Like everything: there are pros and cons.

Best,

Dave


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Tony Williams [MYF]]
      #201578 - 06/15/08 09:51 AM

Quote:

Is that the P-Baron that's sitting at Carlsbad, CA ?




Tony: last I heard it was up in Washington, but I need to get an update.

Best,

Dave


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Rick Durden
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201591 - 06/15/08 11:23 AM

Dave,

I'm curious about range and useful load - the horrendous problem of the small airframes and turbine engines is the inability to carry enough fuel for decent range and still be able to put something in the cabin. It pretty much meant the turbine P210 and Bonanza wouldn't really work out; Piper only recently solved the issue on the Meridian by installing VGs to get the stall speed under control so now it will take three plus baggage when full of gas (1,000 nm VFR range, plus or minus 850 IFR) and no matter what, you've got to get up in the 20s to get any range and endurance.

My other area of curiousity is airframe changes needed for the speeds desired - when Riley put together a turbine version of the Cessna 421 it just didn't work; the airframe wasn't designed for that kind of horsepower - when Cessna made the 425 it only superficially resembled the 421 due to all the changes that had to be made to the airframe to handle the power upgrade. When Piper developed the Meridian from the Malibu/Mirage the only thing that wound up being common the fuselage....

Warmest regards,
Rick


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Jeff Hartmann CIC
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201602 - 06/15/08 12:48 PM

Dave,

There is also the insurance problem (maybe), unless someone builds a sim.

--------------------
Jeff

nothing clever to say right now...


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Rick Durden]
      #201603 - 06/15/08 12:53 PM Attachment (879 downloads)

Quote:

Dave,

I'm curious about range and useful load - the horrendous problem of the small airframes and turbine engines is the inability to carry enough fuel for decent range and still be able to put something in the cabin. It pretty much meant the turbine P210 and Bonanza wouldn't really work out; Piper only recently solved the issue on the Meridian by installing VGs to get the stall speed under control so now it will take three plus baggage when full of gas (1,000 nm VFR range, plus or minus 850 IFR) and no matter what, you've got to get up in the 20s to get any range and endurance.

My other area of curiousity is airframe changes needed for the speeds desired - when Riley put together a turbine version of the Cessna 421 it just didn't work; the airframe wasn't designed for that kind of horsepower - when Cessna made the 425 it only superficially resembled the 421 due to all the changes that had to be made to the airframe to handle the power upgrade. When Piper developed the Meridian from the Malibu/Mirage the only thing that wound up being common the fuselage....

Warmest regards,
Rick




Rick:

I had asked about the range and the representation made wasn't bad. I'd have to go back to my notes, but the factory P-Baron carries 190 useful. Darwin was going to add fuel in the nacelle which would bring it up to 230 to 235 IIRC. You probably know more about the -21 burn rate than I do. Of course, numbers were projected on getting up to FL250 fast.

One could pull the power back to a long range fuel burn and get better range, over 1,000NM according to him.

I share your concerns about the airframe; Darwin represents it as being robust. Please understand that I've only briefly looked into this as a potential customer. Haven't been out there, haven't flown the bird and am not a test pilot. I have attached an e-mail from him and his spec sheet. I certainly welcome other folk's thoughts. Don't think I'm headed in this direction right now because my business is in the toilet, but who knows.

Best,

Dave

Edited by Dave Siciliano (ADS) (06/15/08 01:03 PM)


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201604 - 06/15/08 12:55 PM Attachment (507 downloads)

Here are some discussion notes and an e-mail from Darwin (attached).

Best,

Dave


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Jeff Hartmann CIC]
      #201605 - 06/15/08 01:00 PM

Quote:

Dave,

There is also the insurance problem (maybe), unless someone builds a sim.




Jeff:

Excellent point! All I can say is I asked about that. I didn't check with my agent as I wasn't far enough along to get that detailed. Darwin says it hasn't been an issue on the Malibu or Duke conversions they've done.

Since I do attend annual recurrent training at SIMCOM, I would have to see if that would be accepted in the future if I went that direction.

Best,

Dave


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Curtis Sanford (SQL)
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201661 - 06/15/08 10:05 PM

Quote:

Of course, high speed cruise is more to show off. Long range cruise would be more practical.



In the PT6 applications I've flown, high-speed cruise was the most economical once you took the (hours-based) engine reserves into account. Of course with $6 Jet-A that may be changing.

-Curt


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Curtis Sanford (SQL)]
      #201707 - 06/16/08 11:06 AM

Quote:

Quote:

Of course, high speed cruise is more to show off. Long range cruise would be more practical.



In the PT6 applications I've flown, high-speed cruise was the most economical once you took the (hours-based) engine reserves into account. Of course with $6 Jet-A that may be changing.

-Curt




Curt:

Did you look at the fuel flow amounts Darwin provided? In light of that, and the cost of fuel, why would high speed cruise be more economical? Is it because of engine time replacements?
I don't have any time behind -21s. The turbine time I do have was courtesy of Uncle Sam.

Best,

Dave


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Ralph Jones
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #201708 - 06/16/08 11:12 AM

I'll add one data point: Having your glider towed by a sprayer with a PT-6 is eye-opening <g>.

--------------------
Ralph Jones
LS-4a N49LS 6R


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Tom Tyson [SUW]
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Re: Turbine P-Baron [Re: Ralph Jones]
      #201800 - 06/16/08 08:18 PM

Quote:

Having your glider towed by a sprayer with a PT-6 is eye-opening




Yessir! Even with my heavy as #=!!, water laiden open class bird at Uvalde in August - moved up right smart I'd say.

The log book says that according to the recording GPS, the tow lasted 41 seconds from start of roll to release at 2130' AGL. It is the only tow I remember where the only reference I had to staying in position behind the tow plane was the wing-tips poking out on either side of my nose - I probably had a deck angle of 15 degrees or so, even with full flaps. No way I could see him over the nose. Flew the whole tow with one hand on the release, just in case.

- TT

--------------------
Tom Tyson-A&P

Pilots without Mechanics are just Pedestrians with fancy watches.

Edited by Tom Tyson [KGSO] (06/16/08 08:25 PM)


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Tom Tyson [SUW]
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Re: Turbine P-Baron [Re: Tom Tyson [SUW]]
      #206789 - 07/29/08 10:20 AM

OOPS! Make that 101 seconds, or 1:41 minutes (someday I'll learn to type, or at least proof-read my posts.)

Still mighty impressive from my perspective.

- TT

--------------------
Tom Tyson-A&P

Pilots without Mechanics are just Pedestrians with fancy watches.


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213720 - 09/19/08 04:07 PM

Here's the latest from Darwin at Rocket Engineering.

Best,

Dave

David, We are pleased to announce the first flight of the Turbine Cougar Baron.

The first flight was September 16,2008 and since then it has flown 4 more times.

The performance is better than expected and the flight and handling qualities are

very docile, much, much better than the original. Takeoff is awesome, power up to

500# torque, release brakes and in 6 seconds the aircraft is passing through 80 kias

with smooth rotation up to 140 kias and at full power (500 hp/side) the climb rate is

between 4000 to 5000 fpm. We have only been to 13,500 so far and 200 kias is

achieved on only 24 gallons per side.



We will have more data to send you in the next few weeks but I though you would

appreciate this info. I have flight tested for the FAA many aircraft and this is by far

the highest performance aircraft I have ever flown, the Ferrari of aircraft.



Darwin Conrad


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Rick Durden
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213729 - 09/19/08 04:47 PM

"only" 24 gph per side????

To my knowledge they can't put tip tanks on that wing.


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Robert Mann [HPN-NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213730 - 09/19/08 04:55 PM

Dave,

Next time you speak/write to Darwin, please say "hello" to him for me.

--------------------
Best,

Bob


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Scott Dyer [HPN/NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213732 - 09/19/08 05:09 PM

Dave -- I thought there weren't any rich people left after this week?!
Wonder who is going to buy.

--------------------
www.scottdyercfi.com


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Jeff Hartmann CIC
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Re: Turbine P-Baron [Re: Scott Dyer [HPN/NY]]
      #213737 - 09/19/08 05:14 PM

Scott,

>>>I thought there weren't any rich people left after this week?! <<<

I talked to someone today that said Lehman had a G450 for sale..

They have a delivery for next month on a new G550..

I wonder who will buy that position, from what I hear that's no problem.

--------------------
Jeff

nothing clever to say right now...


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Rick Durden]
      #213738 - 09/19/08 05:15 PM

I think I posted some projected fuel burns in the past. 24 per side at 200 IAS at 13,500 is what I think was being said. Obviously, better TAS at lower fuel burn higher on the PT-6. Oh, the P-Baron hold 190 useable. Darwin was putting a bit more in the nacelle; IIRC he thought 220 to 230 useable.

Best,

Dave

Edited by Dave Siciliano (ADS) (09/19/08 05:16 PM)


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Robert Mann [HPN-NY]]
      #213739 - 09/19/08 05:15 PM

Quote:

Dave,

Next time you speak/write to Darwin, please say "hello" to him for me.




Wilco!

Best,

Dave


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Scott Dyer [HPN/NY]
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Re: Turbine P-Baron [Re: Jeff Hartmann CIC]
      #213743 - 09/19/08 05:37 PM

Jeff -- Probablhy someone from Europe. Or Asia or the Gulf.

All I can tell you is that corporate America, of the kind that flies these
jets, is reeling. Thank goodness this week is ending.

--------------------
www.scottdyercfi.com


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Robert Mann [HPN-NY]
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Re: Turbine P-Baron [Re: Scott Dyer [HPN/NY]]
      #213744 - 09/19/08 05:37 PM

Scott,

<<Dave -- I thought there weren't any rich people left after this week?!>>

Dave mortgaged the farm and shorted the financials last Friday, and covered Wednesday afternoon. I don't make a move without him.

--------------------
Best,

Bob


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Scott Dyer [HPN/NY]]
      #213749 - 09/19/08 06:48 PM

Quote:

Dave -- I thought there weren't any rich people left after this week?!
Wonder who is going to buy.




Huh? Ya mean I can't use 40 to 1 leverage anymore with a negatively amortizing balloon note? Guess I'll haveta reconsider <g>

Of course, that's an excellent point. Seems a lot of this stuff is formulated and announced what the good times are rolling along. Actually have people state that aircraft are great investments when the economy is on rock and roll. Saw more B-200 King Airs for sale in TAP last issue than I've ever seen, but maybe it's just me since I don't shop for those a lot.

Best,

Dave


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Robert Mann [HPN-NY]]
      #213750 - 09/19/08 06:51 PM

Quote:

Scott,

<<Dave -- I thought there weren't any rich people left after this week?!>>

Dave mortgaged the farm and shorted the financials last Friday, and covered Wednesday afternoon. I don't make a move without him.




Ya know, I should post my new trading positions on the board when I place them. Then, one could just take the opposite side and one of us, at least, would make money.

I hate to say it, but I actually did well when the market fell. Thought some things would go down because of business conditions and took a position in puts; then, Uncle Sam decided it should stabilize the market. So much for that.

Best,

Dave


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Scott Dyer [HPN/NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213765 - 09/19/08 08:02 PM

Dave -- Lots of aircraft for sale, and lots of McMansions too, around here.
Makes one glad to live within one's means.

--------------------
www.scottdyercfi.com


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Scott Dyer [HPN/NY]]
      #213767 - 09/19/08 08:25 PM

Quote:

Dave -- Lots of aircraft for sale, and lots of McMansions too, around here.
Makes one glad to live within one's means.




Scott: If more folks thought like you, we wouldn't be where we are! But, no matter how we got here; here we are!

Wasn't if Yogi that said, if you see a fork in the road, take it <g>. Don't know what this has to do with your post, but it sounded good.

Best,

Dave


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Scott Dyer [HPN/NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213777 - 09/19/08 09:33 PM

Dave -- Yogi sounds good to me, anytime!

--------------------
www.scottdyercfi.com


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Robert Mann [HPN-NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213784 - 09/19/08 10:55 PM

Dave,

<< better TAS at lower fuel burn higher >>

Is it both? I always thought that it's more TAS on the same fuel burn, or in other words, more mpg.

--------------------
Best,

Bob


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Robert Mann [HPN-NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213787 - 09/19/08 11:25 PM

Dave,

<< I should post my new trading positions on the board when I place them. Then, one could just take the opposite side >>

There were some advisors I knew that always made the worst decisions. I used to rib them and say that I'm going to launch a new mutual fund called The Joe Smith Contrafund, which would do just the opposite of whatever he did. I also thought about saying the same things to some ex-clients, but I kept those thoughts to myself.

Some clients are really good at telling you where the bottom is. It's when they say, "Maybe we should just go to cash and wait this thing out."

--------------------
Best,

Bob


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Robert Mann [HPN-NY]
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Re: Turbine P-Baron [Re: Scott Dyer [HPN/NY]]
      #213790 - 09/19/08 11:41 PM

Scott,

<<and lots of McMansions too, around here>>

Wait till the demographics of later/no marriages and smaller families really sink in. Who's going to be buying those things in 10-20 years? Problem is, the economics of development tell you that you're going to lose money if you don't build at least a 3,000 sq ft house, and you'll make a lot more money if you build a 6,000 sq ft house. The land cost the same either way. I'm sure you've seen lots around here that sell for less money with a small house on them than they would if it were vacant land.

--------------------
Best,

Bob


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Robert Mann [HPN-NY]]
      #213792 - 09/19/08 11:45 PM

Quote:

Dave,

<< better TAS at lower fuel burn higher >>

Is it both? I always thought that it's more TAS on the same fuel burn, or in other words, more mpg.




I'll get you some C-90 performance data in the morning.

In general, fuel flows are quite high at lower altitude while TAS is lower; after one climbs with these engine and gets into the thinner air, TAS is higher while fuel burn is lower. I'll get you some specifics when I can access it. In the E-90 King air I was recently given a demo flight in, it burned over 700PPH in the climb; high speed cruise was just over 300PPH IIRC at FL270. Since we didn't level off at a middle altitude, I don't have those numbers, but can get them int he morning. Maybe someone else has them handy tonight.

Best,

Dave


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213810 - 09/20/08 12:24 PM

Robert:

I have the data for a C-90 with the -135s (Blackhawk STCed engines). That's what we have looked at and a friend of mine has one.

At 10,000 feet, he gets 265 knots at 700 PPH fuel flow.

At 20,000 feet, he gets 272 knots at 525 PPH fuel flow.

At 25,000 feet, he gets 269 knots at 440 PPH fuel flow.

So, real low, he's a bit slow and burns a lot more fuel. As you can see, his TAS is best around 20,000, but he doesn't lose much speed and really reduced fuel flow in the mid 20s. Of course, one must consider wind and weather, but, in general, with these engines, he's better off in the mid 20s.

Best,

Dave


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Robert Mann [HPN-NY]
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Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213815 - 09/20/08 12:45 PM

Dave,

That's a huge difference in FF. When I asked whether it was "both", I guess it's always a tradeoff between TAS and FF. For instance, at 10,000 ft, if FF was 440 PPH, I imagine that TAS would be in the 200-220 range. So, as one increases altitude, either TAS goes up, FF goes down, or both, depending on your power settings.

IIRC, the difference is much more severe for a turbofan engine vs a turboprop. I don't really understand the theory behind that, but is that correct?

--------------------
Best,

Bob


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Dave Siciliano (ADS)
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Re: Turbine P-Baron [Re: Robert Mann [HPN-NY]]
      #213820 - 09/20/08 01:50 PM

Quote:

Dave,

That's a huge difference in FF. When I asked whether it was "both", I guess it's always a tradeoff between TAS and FF. For instance, at 10,000 ft, if FF was 440 PPH, I imagine that TAS would be in the 200-220 range. So, as one increases altitude, either TAS goes up, FF goes down, or both, depending on your power settings.

IIRC, the difference is much more severe for a turbofan engine vs a turboprop. I don't really understand the theory behind that, but is that correct?




There certainly are many folks out there that can explain this better than me, but I'll give it a general go and be happy for anyone else to chime in. The turbines are a bit different in the way they are run; unlike a prop, they seem to do better at recommended power settings; that is you don't run them too hot or too cold. So, you are correct in that if one ran 440PPH at 10,000 feet, TAS would be down, but one generally wouldn't run a low power setting like that a lot. The small amount of fuel savings is offset by the cycle cost on the plane.

While turbines could be more efficient lower, most are set up to get maximum efficiency higher. The compressors (which could be compared to the turbo on a recip) produce full power up to an altitude, then, power drops off. So, the old C-90 King air engines made full power up to about 14,000 on a standard day and power dropped off above that. One would still benefit from being higher as the air was thinner and TAS would still be high with lower fuel burn as in the expamle I provided. The -135s on the Blackhawk conversion plane, maintain full power to a higher altitude; so, the sweet spot is mid 20s as opposed to low 20s on earlier King Airs.

I yield to the next speaker that can explain turbine efficiency better <g>

Best,

Dave

Edited by Dave Siciliano (ADS) (09/20/08 01:52 PM)


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Mase Taylor
Top Gun


Reged: 04/29/04
Posts: 9446
Loc: SOCAL
Re: Turbine P-Baron [Re: Dave Siciliano (ADS)]
      #213821 - 09/20/08 02:09 PM

When Hawker/Beech re-engined the C90 King Air to make the C90GT, they replaced 550shp PT6A-21 engines with 550shp PT6A-135A engines. Why bother, you say? Because the -135A engines are derated; they are thermodynamically capable of 750shp. So they can maintain full rated power of 550shp to a much higher altitude without overtemping. This make the C90GT almost 30 kt faster, and much better climb performance.

--------------------
Fly The Airplane As Far Into The Crash As Possible. - Bob Hoover 1922-2016 R.I.P.


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Dave Siciliano (ADS)
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Reged: 05/17/04
Posts: 8469
Loc: ADS (Dallas, TX)
Re: Turbine P-Baron [Re: Mase Taylor]
      #213831 - 09/20/08 03:42 PM

Quote:

When Hawker/Beech re-engined the C90 King Air to make the C90GT, they replaced 550shp PT6A-21 engines with 550shp PT6A-135A engines. Why bother, you say? Because the -135A engines are derated; they are thermodynamically capable of 750shp. So they can maintain full rated power of 550shp to a much higher altitude without overtemping. This make the C90GT almost 30 kt faster, and much better climb performance.




Thanks Mase! Robert, if you have the same amount of power; you'll true out faster higher up.
According to Conklin & de Decker:

Up to about 14,000 feet at ISA, the PT6A-21 delivers its full take-off torque. At recommended cruise, this is 1,315 Ft.- Lbs per engine. Above this altitude, the engine loses torque and at 26,000 feet produces only 862 Ft.-Lbs of torque. This yields 235 KTAS for a mid-weight King Air C90A.

Just to compare the -135s: and I quote again:
At normal cruise, the PT6A-135A produced 1,520 Ft-Lbs. up to 18,000 feet. At 26,000 feet is still produces 1,170 Ft-Lbs. torque - 36% more power than the PT6A-21.

So, constant torque on the -21 up to 14,000, then, it declines. For the -135s, torque remains constant up to 18,000 feet; then, declines. This is primarily do to a better compressor.

Did this answer your question? Sorry to get into the new engine, but it shows how the same power is made to a higher altitude.

Best,

Dave


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