Turbine Duke or turbine Baron?

There's also a guy in Germany working on a conversion of the Duke to
twin Thielert diesels - the big ones doing 350 HP. He's got one
flying.

I read the article - wow that's a huuuuge bump in range over the
gassers eh? Didn't know Lyc wasn't supporting the TIO-541 anymore (I
think the P-Navajo has the same engine?) but doesn't surprise me as
I've heard they're quite finicky and must be babied more than most high
HP turbo'd piston engines.

A lot of small businesses bought Dukes and hired the
cheapest high time pilot they could find, usually it seems
that was a retired B47/B52 Colonel who didn't know better
than to slam the throttles open - closed just like he did in
those other airplanes. The Dukes that I saw, that were
flown by civilian trained pilots usually flew pretty trouble
free to TBO. The ones that were flown by retired jet jocks
needed turbo replacement at 600-800 hours and new cylinders
at 1,000. They saved a buck on the salary and spent a ton
on maintenance.


--
James H. Macklin
ATP,CFI,A&P

wrote in message
oups.com...
| There's also a guy in Germany working on a conversion
of the Duke to
| twin Thielert diesels - the big ones doing 350 HP. He's
got one
| flying.
|
| I read the article - wow that's a huuuuge bump in range
over the
| gassers eh? Didn't know Lyc wasn't supporting the TIO-541
anymore (I
| think the P-Navajo has the same engine?) but doesn't
surprise me as
| I've heard they're quite finicky and must be babied more
than most high
| HP turbo'd piston engines.
|

The Dukes that I saw, that were flown by civilian trained pilots usually flew pretty trouble free to TBO.


Another BS hangar myth destroyed. I've heard the same of the Cessna 421
from a few guys who've owned/flown them. Most of what I'd heard
previously about that type was the turbo'd & geared Contis were a
complete pain in the arse and would never make TBO without new jugs or
worse. I guess ya gotta question just how qualified somebody is when
they start talking trash about airplanes & engines, huh?

Thanks,
Wooly

There is some truth in many stories, but with any
turbocharged aircraft engine, allowing the temperatures and
clearances to normalize is critical. A turbo may be at
70,000-100,000 RPM, at 1400 degrees on one end of the shaft
and just a few hundred on the other. The cylinder heads may
be at 375-425 degrees and when you cut the power to idle the
heads shock cool, the turbo cools and that includes the
housing which can shrink faster than the impeller. The next
thing is that the housing and impeller make contact and
grind away. The turbo may spin for some time after
shutdown, without any engine oil pressure or flow. If the
pilot lands on the far side of the airport or stops on the
ramp/taxiway to allow the turbo to spin down and more
importantly cool, the oil will flow and cool the turbo
bearings and the oil won't fail (coke) extending the turbo
life. From 40-to 30 inches you can move the throttle
smoothly, but I would never go below 20 inches in-flight and
then not until I'd flown a minute at 25 inches. I used the
cowl flaps to keep the engine warm on approach and opened
them for all ground and T..O/climb operations. I used full
rich in the climb and I made sure to observe the TIT limits
as well as oil and cylinder temps.
I rarely flew any single airplane more than a dozen times,
but I saw many airplanes that were flown thousands of hours
by one pilot.

One thing about the Duke, I always made a modified soft
field take-off, using full back elevator until I got to
about 50 kts, then I'd fly the nose down to prevent a
premature take-off. The Duke sits with a negative angle of
attack and the engines will drive the nose down unless the
pilot lightens the load on the nose wheel. Take-off
performance is much improved with this technique.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm



wrote in message
ups.com...
| The Dukes that I saw, that were flown by civilian
trained pilots usually flew pretty trouble free to TBO.
|
|
| Another BS hangar myth destroyed. I've heard the same of
the Cessna 421
| from a few guys who've owned/flown them. Most of what I'd
heard
| previously about that type was the turbo'd & geared Contis
were a
| complete pain in the arse and would never make TBO without
new jugs or
| worse. I guess ya gotta question just how qualified
somebody is when
| they start talking trash about airplanes & engines, huh?
|
| Thanks,
| Wooly
|

("Thomas Borchert" wrote)
There's also a guy in Germany working on a conversion of the Duke to
twin Thielert diesels - the big ones doing 350 HP. He's got one flying.

See http://info.thielert.com/centurion/m...php?newsid=340

(From the link)
"The Centurion 4.0 of the GmbH Thielert Aircraft Engines is a V8-engine with
state-of-the-art technology, and in the twin it replaces the initially
built-in Lycoming IO-541-E1C4 which is not produced anymore. Furthermore the
manufacturer discontinued the product support for the IO-541-E1C4.

In comparison the diesel conversion weighs 20 kilograms (50 lbs) less. The
entire consumption was 22 gallons of kerosene per hour, which sums up to 8
gallons less fuel consumption. For this reason the range of the Duke
increases from 1100 Nautical Miles to 2000 Nautical Miles."


Huh? So the Duke was getting 15 per side (30) and now gets 11 per side (22)?

30 gal x 6 lbs = 180 lbs fuel/hr ...Avgas
22 gal x 7 lbs = 154 lbs fuel/hr ...Diesel (Saving 26 lbs/hr fuel weight)

I don't see how that almost doubles the Nautical Miles? Six hours of diesel
flight gets you a free hour. (6 hrs x 26 lbs/hr (saved) = 156 lbs)

Add in the diesel conversion saving of 50 lbs? I still don't get it.

If there was an increase in speed, I would think Thielert would want that
little extra bonus fact front and center.


Montblack

("Montblack" wrote)
In comparison the diesel conversion weighs 20 kilograms (50 lbs) less. The
entire consumption was 22 gallons of kerosene per hour, which sums up to 8
gallons less fuel consumption. For this reason the range of the Duke
increases from 1100 Nautical Miles to 2000 Nautical Miles."


Huh? So the Duke was getting 15 per side (30) and now gets 11 per side
(22)?

30 gal x 6 lbs = 180 lbs fuel/hr ...Avgas
22 gal x 7 lbs = 154 lbs fuel/hr ...Diesel (Saving 26 lbs/hr fuel weight)

I don't see how that almost doubles the Nautical Miles? Six hours of
diesel flight gets you a free hour. (6 hrs x 26 lbs/hr (saved) = 156 lbs)


Is it 30 gals ...per side? Turbo'd!

So now it's every "three" hours you get a bonus hour of fuel. Will that get
you an extra 900 Nautical Miles?

Does "entire consumption" mean per engine or ...entire, as in both,
combined? Now I don't know what "sum" means either. Oh well.


Montblack