Finally: The right-sized Thielert

[Thomas Borchert]

Thielert has announced a diesel engine in the 230-HP-range, covering
the gap between the existing 135- and 350-HP models. Great news, IMHO,
since this is the kind of power many of the planes we fly need. First
target for certification seems to be the 182. Time frame is 2007. Nice!


--
Thomas Borchert (EDDH)

[Ronnie]

It would be interested to see what their cost would
be for an engine that was certified to replace the 250HP
Lycoming IO-540C4B5 engines on my Aztec. I'd
guess that even at engine overhaul time, econmics
would be vastly in favor of overhauling the old engines
as compared to replacing them with diesels.

Ronnie

"Thomas Borchert" > wrote in message
...
> Thielert has announced a diesel engine in the 230-HP-range, covering
> the gap between the existing 135- and 350-HP models. Great news, IMHO,
> since this is the kind of power many of the planes we fly need. First
> target for certification seems to be the 182. Time frame is 2007. Nice!
>
>
> --
> Thomas Borchert (EDDH)
>
>

[[email protected]]

Ronnie > wrote:
> It would be interested to see what their cost would
> be for an engine that was certified to replace the 250HP
> Lycoming IO-540C4B5 engines on my Aztec. I'd
> guess that even at engine overhaul time, econmics
> would be vastly in favor of overhauling the old engines
> as compared to replacing them with diesels.

> Ronnie

> "Thomas Borchert" > wrote in message
> ...
> > Thielert has announced a diesel engine in the 230-HP-range, covering
> > the gap between the existing 135- and 350-HP models. Great news, IMHO,
> > since this is the kind of power many of the planes we fly need. First
> > target for certification seems to be the 182. Time frame is 2007. Nice!
> >
> >
> > --
> > Thomas Borchert (EDDH)

My thought is it is going to depend on a lot of factors.

Will the cost of swapping a gas engine for a diesel come down as
they become (if it happens) more common?

How will the life-cycle costs compare? Supposedly the diesels require
less maintenance over their life. Whether that is really true or
not remains to be seen. Right now about the only thing for sure is you
don't have to replace spark plugs.

What is going to happen to fuel costs? Right now Jet A is $.87/gal
cheaper at my local FBO. Will this spread increase or decrease?

Will a FADEC diesel further reduce the fuel costs by keeping everything
optimal?

No matter what happens with the above, putting a different engine
in will cost more than putting in a new engine of the same type.
How long do you expect to keep the airplane and how many engines
do you expect to replace/overhaul during that time?

etc.

--
Jim Pennino

Remove .spam.sux to reply.

[nrp]

The biggest cost item is what will the insurance companies consider to
be the likely product liability costs of this new powerplant? Remember
the liability tail is still 18 years, and even this is reset if parts
are replaced. Insurance companies are pretty conservative on
innovation, and for good reasons.

My read on it is that over a long term, the US light aircraft industry
is destined to go overseas where the liability costs of innovation are
less. We'll still have new aircraft (occasionally) but without
additional tort reform in the US, the imported costs will continue to
rise.

[Thomas Borchert]

Ronnie,

> I'd
> guess that even at engine overhaul time, econmics
> would be vastly in favor of overhauling the old engines
> as compared to replacing them with diesels.
>

Of course it will be more expensive. After all, you're getting a brand
new engine. Apart from that, a lot depends. The way Thielert does it
here, they guarantee you 2400 hours (or, I think, 12 years). Thus, you
absolutely truly know from the start what one of those hours will cost
engine-wise: The cost of the engine divided by 2400. That's it, period.
If it breaks before that, you'll get a new one prorated. So, if you fly
200 hours per year, your cost savings could be substantial. Also it
uses a lot less fuel. If you fly a lot, that will pay of sooner.


--
Thomas Borchert (EDDH)

[M]

Diesel actually has a substantial advande in fuel economy. The Tielert
diesel claims to have a BSFC of 0.33lb/HP-hr, far better than the
gasoline engines that're usually at 0.40-0.45 range. If you think this
is not significant, consider that diesel weighs more per gallon than
avgas, and we buy fuel in volume, not weight. So a 25% improvement of
BSFC by going diesel will actually result in 28% of saving in the
volume (gallon) of fuel burn. If the cost of diesel per gallons is 20%
lower than avgas, the total fuel cost saving is going to be about 34%
in dollar amount. That's very significant over the life time of an
engine.


wrote:
>
> What is going to happen to fuel costs? Right now Jet A is $.87/gal
> cheaper at my local FBO. Will this spread increase or decrease?
>
> Will a FADEC diesel further reduce the fuel costs by keeping everything
> optimal?

[Ronnie]

I thought the fuel for these aviation diesel engine
was Jet A. Is the data below for Jet A or for
diesel fuel?

How does Jet A compare to gasoline?

Ronnie

"M" > wrote in message
ps.com...
>
> Diesel actually has a substantial advande in fuel economy. The Tielert
> diesel claims to have a BSFC of 0.33lb/HP-hr, far better than the
> gasoline engines that're usually at 0.40-0.45 range. If you think this
> is not significant, consider that diesel weighs more per gallon than
> avgas, and we buy fuel in volume, not weight. So a 25% improvement of
> BSFC by going diesel will actually result in 28% of saving in the
> volume (gallon) of fuel burn. If the cost of diesel per gallons is 20%
> lower than avgas, the total fuel cost saving is going to be about 34%
> in dollar amount. That's very significant over the life time of an
> engine.
>
>
> wrote:
>>
>> What is going to happen to fuel costs? Right now Jet A is $.87/gal
>> cheaper at my local FBO. Will this spread increase or decrease?
>>
>> Will a FADEC diesel further reduce the fuel costs by keeping everything
>> optimal?
>
>

[M]

I was using the term diesel fuel in a generic sense. Yes the math is
based on Jet A because it's 6.84lb/gal compared with 6lb/gal of avgas.

Ronnie wrote:
> I thought the fuel for these aviation diesel engine
> was Jet A. Is the data below for Jet A or for
> diesel fuel?
>
> How does Jet A compare to gasoline?

[BTIZ]

Jet A is more expensive out our local pumps than 100LL but about 80cents.
BT

"M" > wrote in message
ps.com...
>
> Diesel actually has a substantial advande in fuel economy. The Tielert
> diesel claims to have a BSFC of 0.33lb/HP-hr, far better than the
> gasoline engines that're usually at 0.40-0.45 range. If you think this
> is not significant, consider that diesel weighs more per gallon than
> avgas, and we buy fuel in volume, not weight. So a 25% improvement of
> BSFC by going diesel will actually result in 28% of saving in the
> volume (gallon) of fuel burn. If the cost of diesel per gallons is 20%
> lower than avgas, the total fuel cost saving is going to be about 34%
> in dollar amount. That's very significant over the life time of an
> engine.
>
>
> wrote:
>>
>> What is going to happen to fuel costs? Right now Jet A is $.87/gal
>> cheaper at my local FBO. Will this spread increase or decrease?
>>
>> Will a FADEC diesel further reduce the fuel costs by keeping everything
>> optimal?
>

[soxinbox]

I wonder whether its constant speed or constant pitch. I also wonder how
much useful load it eats up.


"Thomas Borchert" > wrote in message
...
> Thielert has announced a diesel engine in the 230-HP-range, covering
> the gap between the existing 135- and 350-HP models. Great news, IMHO,
> since this is the kind of power many of the planes we fly need. First
> target for certification seems to be the 182. Time frame is 2007. Nice!
>
>
> --
> Thomas Borchert (EDDH)
>

[Don Tuite]

On Wed, 17 May 2006 17:42:17 -0700, "BTIZ" >
wrote:

>Jet A is more expensive out our local pumps than 100LL but about 80cents.
>BT

How much is home heating oil?

Don

[Matt Barrow]

"BTIZ" > wrote in message
news:JpPag.1293$rS6.170@fed1read11...
> Jet A is more expensive out our local pumps than 100LL but about 80cents.
> BT
>
Fairly common in areas where the "jet-setters" congregate, like Jackson
Hole, Squaw Valley, Aspen...

[[email protected]]

On 17-May-2006, "soxinbox" > wrote:

> I wonder whether its constant speed or constant pitch. I also wonder how
> much useful load it eats up.


I believe that the Thielert engines tend to be a bit lighter than gasoline
engines of comparable power. Useful load probably won't change that much
but PAYLOAD should get a nice bump up because the diesel's lower SFC means
less fuel will be needed for a given mission, even taking into account that
diesel fuel (which is essentially the same as Jet-A) is slightly heavier (in
lbs/gal) than gasoline.

I strongly suspect that any modern piston aircraft engine over 200 hp will
be configurable for a constant speed prop. However, FADEC might take
control of RPMs out of the pilot's hands


-Elliott Drucker

[M]

wrote:
> Useful load probably won't change that much
> but PAYLOAD should get a nice bump up because the diesel's lower SFC means
> less fuel will be needed for a given mission, even taking into account that
> diesel fuel (which is essentially the same as Jet-A) is slightly heavier (in
> lbs/gal) than gasoline.

Actually in this discussion, the density of the jet fuel isn't a factor
because BSFC is based on weight, not volume. Diesel engine has a lower
BSFC means it needs less weight of the fuel to produce the same amount
of power.

[Thomas Borchert]

Soxinbox,

> I wonder whether its constant speed or constant pitch.
>

Speed. But you as a pilot don't get to select it. There's just one
single lever for "noise control": Forward means more noise, pull back
and it gets quieter. That lever doesn't even have any mechanical
connection to the engine, only an electrical link to the engine control
units.

Oh, and the reaction to this information says a lot about how much a
pilot really wants innovation in aviation.

--
Thomas Borchert (EDDH)

[David Lesher]

"Ronnie" > writes:

>I thought the fuel for these aviation diesel engine
>was Jet A. Is the data below for Jet A or for
>diesel fuel?

>How does Jet A compare to gasoline?


Jet A == kerosene.

Gasoline is 6.25 lbs/gallon {at ~70F}
Kero is 6.84 lbs/gallon...

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[J. Severyn]

"Thomas Borchert" > wrote in message
...
>
> Oh, and the reaction to this information says a lot about how much a
> pilot really wants innovation in aviation.
>
> --
> Thomas Borchert (EDDH)
>
Nope. It says how much a pilot wants to trust a small computer and its
software and engine actuators.
John Severyn @KLVK

[Thomas Borchert]

J.,

> It says how much a pilot wants to trust a small computer and its
> software and engine actuators.
>

instead of a small mechanical linkage and its hardware?

--
Thomas Borchert (EDDH)

[Bob Noel]

In article >,
Thomas Borchert > wrote:

> > It says how much a pilot wants to trust a small computer and its
> > software and engine actuators.
>
> instead of a small mechanical linkage and its hardware?

Hardware failure modes are much better understood.

What's the reliability of software?

--
Bob Noel
Looking for a sig the
lawyers will hate

[Thomas Borchert]

Bob,

> Hardware failure modes are much better understood.

Says who? Numbers, please.

> What's the reliability of software?

Not sure I understand the question.

--
Thomas Borchert (EDDH)

[soxinbox]

Those of us that design computers and write software are probably less
comfortable with the software and computers than the mechanical linkages.
I've seen way to many scary things go out the door.

"Thomas Borchert" > wrote in message
...
> Bob,
>
>> Hardware failure modes are much better understood.
>
> Says who? Numbers, please.
>
>> What's the reliability of software?
>
> Not sure I understand the question.
>
> --
> Thomas Borchert (EDDH)
>

[Thomas Borchert]

Soxinbox,

> Those of us that design computers and write software are probably less
> comfortable with the software and computers than the mechanical linkages.
>

Well, that's not the numbers I asked for, it's just smoke being blown. I
guess you don't have the numbers to back up your claims. Doesn't surprise
me, because I don't think the claim is valid at all. Oh, and yes, I have
designed software, too. Argument by authority still doesn't work.

--
Thomas Borchert (EDDH)

[Bob Noel]

In article >,
Thomas Borchert > wrote:

> > Hardware failure modes are much better understood.
>
> Says who? Numbers, please.

You think you understand software failure modes?
Please enlightment me.


>
> > What's the reliability of software?
>
> Not sure I understand the question.

exactly. Nobody agrees on what software reliability means.
On one hand software never wears out. It doesn't break.
However, it is fielded with errors. So it's already broken.
Or is it? The error doesn't manifest itself until the broken
code is executed...

And this discussion is pretty much independent of whether the
software error is a design flaw or an implementation flaw.

--
Bob Noel
Looking for a sig the
lawyers will hate

[Thomas Borchert]

Bob,

> > > Hardware failure modes are much better understood.
> >
> > Says who? Numbers, please.
>
> You think you understand software failure modes?
> Please enlightment me.

You made a claim. You back it up.

> > > What's the reliability of software?
> >
> > Not sure I understand the question.
>
> exactly. Nobody agrees on what software reliability means.

I guess the ton of scientific literature out there disagrees. Just one
link easily found:
http://satc.gsfc.nasa.gov/support/ISSRE_NOV98/software_metrics_and_reli
ability.html


--
Thomas Borchert (EDDH)

[Aaron Coolidge]

Thomas Borchert > wrote:
: Thielert has announced a diesel engine in the 230-HP-range, covering
: the gap between the existing 135- and 350-HP models. Great news, IMHO,
: since this is the kind of power many of the planes we fly need. First
: target for certification seems to be the 182. Time frame is 2007. Nice!

They also expanded the STC for the 135hp unit to include a larger
number of PA28. Unfortunately on the PA28-180 the MGTOW is reduced
from 2400 to 2150 lbs.
--
Aaron C.

[nrp]

> > exactly. Nobody agrees on what software reliability means.

Both Airbus and Boeing have been having trouble with flight control
software according to a Wall Street Journal article a few days ago.

[soxinbox]

Exactly what claims did I make that you want numbers for?? Did you confuse
me with another poster??
"Thomas Borchert" > wrote in message
...
> Soxinbox,
>
>> Those of us that design computers and write software are probably less
>> comfortable with the software and computers than the mechanical linkages.
>>
>
> Well, that's not the numbers I asked for, it's just smoke being blown. I
> guess you don't have the numbers to back up your claims. Doesn't surprise
> me, because I don't think the claim is valid at all. Oh, and yes, I have
> designed software, too. Argument by authority still doesn't work.
>
> --
> Thomas Borchert (EDDH)
>

[Bob Noel]

In article >,
Thomas Borchert > wrote:

> > exactly. Nobody agrees on what software reliability means.
>
> I guess the ton of scientific literature out there disagrees. Just one
> link easily found:
> http://satc.gsfc.nasa.gov/support/ISSRE_NOV98/software_metrics_and_reli
> ability.html

check out DO-178B, paragraph 12.3.4. (unfortunately, it's not available online
for free)

I've followed the FAA's software certification work since 1998. All of the
public forums and publically available work basically points to a lack of
usable software reliability models. I say public work because there is always
the possibility that an applicant has used software reliability in their
software certification work and this would be likely considered to be
proprietary.

Are you aware of any software reliability models that have been used for
aircraft certification?

Also look at the software stuff available at
http://www.faa.gov/aircraft/air_cert/design_approvals/air_software/
Have I overlooked something?

--
Bob Noel
Looking for a sig the
lawyers will hate

[Dylan Smith]

On 2006-05-29, Bob Noel > wrote:
> In article >,
> Thomas Borchert > wrote:
>
>> > It says how much a pilot wants to trust a small computer and its
>> > software and engine actuators.
>>
>> instead of a small mechanical linkage and its hardware?
>
> Hardware failure modes are much better understood.
>
> What's the reliability of software?

For embedded stuff, seemingly much better. Let's compare like with like:
old cars vs new cars. My first car had completely mechanical engine
components - mechanical points and condenser, vacuum advance etc. It
needed a great deal of maintenance to get any kind of reliability. It
was hard to start on cold, damp days.

In many ways, it was comparable to many aviation engines - high
maintenance and fiddly operation. Consider hot starts on even a brand
new Lycoming fuel injected engine - it needs a different procedure to a
cold start.

My current car's engine is completely electronically controlled. It
doesn't need frequent tune ups, lots of maintenance - basically, just
oil and filters. It starts just as well on a warm dry day as on a cold
damp day. It doesn't suddenly quit because something backed off and got
loose on an ignition component. It is so much more consistent than the
old completely mechanical engine as well as much more reliable. Not to
mention a great deal more fuel efficient and more powerful.

I think engine management systems for aero engines haven't come a moment
too soon rather than continuing with engines with systems from the
1940s. I'd trust an engine with electronic engine management long before
I'd trust a "traditional" aero engine. The airlines agree - all their
engines are now FADEC.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

[Gig 601XL Builder]

"Dylan Smith" > wrote in message
...
> For embedded stuff, seemingly much better. Let's compare like with like:
> old cars vs new cars. My first car had completely mechanical engine
> components - mechanical points and condenser, vacuum advance etc. It
> needed a great deal of maintenance to get any kind of reliability. It
> was hard to start on cold, damp days.


We should let Honda build all engines. If they would put in access for oil
changes they could have welded the hood shut.

[Bob Noel]

In article >,
Dylan Smith > wrote:

> > What's the reliability of software?
>
> For embedded stuff, seemingly much better. Let's compare like with like:
> old cars vs new cars. My first car had completely mechanical engine
> components - mechanical points and condenser, vacuum advance etc. It
> needed a great deal of maintenance to get any kind of reliability. It
> was hard to start on cold, damp days.
>
> In many ways, it was comparable to many aviation engines - high
> maintenance and fiddly operation. Consider hot starts on even a brand
> new Lycoming fuel injected engine - it needs a different procedure to a
> cold start.

I don't consider my lycoming to be high maintenance. And it's dirt simple
to work on.

>
> My current car's engine is completely electronically controlled. It
> doesn't need frequent tune ups, lots of maintenance - basically, just
> oil and filters. It starts just as well on a warm dry day as on a cold
> damp day. It doesn't suddenly quit because something backed off and got
> loose on an ignition component. It is so much more consistent than the
> old completely mechanical engine as well as much more reliable. Not to
> mention a great deal more fuel efficient and more powerful.

How much of the apparent improved reliability is due to improved hardware and
how much is due to software control?

btw - I've had two incidents where the engine in my car died. One was a failure
of the timing belt (rubber belt, believe it or not), and one was a failure of
the electronic control module. While the ECM was a hardware failure, it would
not be required in my first car which was entirely analog/mechanical.

--
Bob Noel
Looking for a sig the
lawyers will hate

[Don Tuite]

On Mon, 05 Jun 2006 17:12:56 -0400, Bob Noel
> wrote:
>
>btw - I've had two incidents where the engine in my car died. One was a failure
>of the timing belt (rubber belt, believe it or not), and one was a failure of
>the electronic control module. While the ECM was a hardware failure, it would
>not be required in my first car which was entirely analog/mechanical.

My first job out of engineering school in 1966 was with Garrett
AiResearch. A major product line was air data computers for military
and commercial jets. Inputs were aneroid, thermocouple, and, in the
case of angle-of-attack, direct vane-to-potentiometer. Outputs were
voltages representing various types of airspeed and altitude, along
with Mach number. Inside, they were all electro-mechanical -- cams,
helipots, and gears. The most pressing engineerig problem was
minimizing gear backlash. The guy at the desk next to mine in the
bullpen had been hired because he was a watchmaker.

Mean Time Between Failure was not bad, considering, but these were not
field-repairable units, and they cost a lot of money.

They would not scale well, technically nor economically, to today's
technology. Eventually, you have to decide that the only thing left
for old Nelly is the glue factory.

Don (Getting long-in-the tooth, himself)

[Aaron Coolidge]

Don Tuite > wrote:
: My first job out of engineering school in 1966 was with Garrett
: AiResearch. A major product line was air data computers for military
: and commercial jets. Inputs were aneroid, thermocouple, and, in the
: case of angle-of-attack, direct vane-to-potentiometer. Outputs were
: voltages representing various types of airspeed and altitude, along
: with Mach number. Inside, they were all electro-mechanical -- cams,
: helipots, and gears. The most pressing engineerig problem was
: minimizing gear backlash. The guy at the desk next to mine in the
: bullpen had been hired because he was a watchmaker.

The inside of those old gas-turbine fuel controls is a wonder of
electromechanical design, too. My favorite has always been the three-
dimensional cams (picture a golf ball with a stylus touching it,
or a Selectric typewriter). The real wonder were the mechanical
fire control "computers" from WW2. I saw the one used in a main
battery turret of BB Massachusetts a few years ago. It is the size of
a coffee table, with perhaps 10 or 15 cranks on its perimeter to
set the inputs. It would take a minimum of 3 men to run it.
--
Aaron C.

[Chris Schmelzer]

In article >,
Dylan Smith > wrote:

> On 2006-06-09, Montblack <Y4-NOT> wrote:
> > Also, is there a rule of thumb to compare the new 135hp Diesel to 160hp or
> > 180hp AvGas engines? On the face of it, it looks like 25-45 fewer hp with
> > the Thielert.
>
> The difference is I think the propeller that comes with the Thielert -
> it's constant speed, so all things remaining equal you get more takeoff
> thrust per horsepower.

And you keep that power to a higher altitude (diesel is TURBO after all)
versus losing HP the moment you leave the ground (or the moment your
density altitude goes up)

On a 100dF day at any altitude, the difference would likely be in favor
of the thielert (especially with CS prop)

--
Chris Schmelzer, MD

[Montblack]

("Aaron Coolidge" wrote)
> They also expanded the STC for the 135hp unit to include a larger number
> of PA28. Unfortunately on the PA28-180 the MGTOW is reduced from 2400 to
> 2150 lbs.


250 lbs!

Because of:
The engine swap weight difference?
A power difference?

....or a combination of the two?

Also, is there a rule of thumb to compare the new 135hp Diesel to 160hp or
180hp AvGas engines? On the face of it, it looks like 25-45 fewer hp with
the Thielert.


Montblack

[Dylan Smith]

On 2006-06-09, Montblack <Y4-NOT> wrote:
> Also, is there a rule of thumb to compare the new 135hp Diesel to 160hp or
> 180hp AvGas engines? On the face of it, it looks like 25-45 fewer hp with
> the Thielert.

The difference is I think the propeller that comes with the Thielert -
it's constant speed, so all things remaining equal you get more takeoff
thrust per horsepower.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

[Aaron Coolidge]

Chris Schmelzer > wrote:
: In article >,
: Dylan Smith > wrote:

:> On 2006-06-09, Montblack <Y4-NOT> wrote:
:> > Also, is there a rule of thumb to compare the new 135hp Diesel to 160hp or
:> > 180hp AvGas engines? On the face of it, it looks like 25-45 fewer hp with
:> > the Thielert.
:>
:> The difference is I think the propeller that comes with the Thielert -
:> it's constant speed, so all things remaining equal you get more takeoff
:> thrust per horsepower.

: And you keep that power to a higher altitude (diesel is TURBO after all)
: versus losing HP the moment you leave the ground (or the moment your
: density altitude goes up)

: On a 100dF day at any altitude, the difference would likely be in favor
: of the thielert (especially with CS prop)

The CS prop helps at takeoff so that the engine can make rated power at
zero airspeed. When moving at cruise speed, it makes no difference if the
engine has a CS prop or a FP prop if the RPM is the same (the FP prop
has the advantage here, because it's lighter).

Cruise power from the O-360 180 HP engine is 75% or 135 HP, obtainable
up to 7500 foot DA. I wouldn't expect to see any performance advantage
at or below this altitude.

The real advantage of the diesel seems to be the vastly reduced fuel flow,
which lets the standard Cherokee tankage get over 9 hours of flying time
(this is the application we're talking about here).
--
Aaron C.

[Bob Noel]

In article >,
Aaron Coolidge > wrote:

> When moving at cruise speed, it makes no difference if the
> engine has a CS prop or a FP prop if the RPM is the same

It does if the pitch of the prop is different

--
Bob Noel
Looking for a sig the
lawyers will hate

[Aaron Coolidge]

Bob Noel > wrote:
: Aaron Coolidge > wrote:

:> When moving at cruise speed, it makes no difference if the
:> engine has a CS prop or a FP prop if the RPM is the same

: It does if the pitch of the prop is different

I should have stated my assumptions. I assumed that the airspeed and the
engine RPM/MP was the same, which leads to the conclusion that the
props would be interchangeable. Sorry about that.
--
Aaron C.