Thielert (Diesel Engines)

On Fri, 15 Feb 2008 13:26:01 +0000 (UTC), Bertie the Bunyip
wrote:



Hmmm, could be. Lots of turboprops have fadecs now. The latest Pratts, I
beleive. I was having this ocnverstation with an FO who had come off a
Dash-8 and he told me the latest version of it ( Q400 or something?) had
them. I said "yeah, but they don't have this problem with power, though,
surely" and he told me that they probably did since power was definitely
required to run the fadec. They tell us very little about the innnards
of these fuel units, but I cant see them icencing an airliner without
enough system seperation to ensure that one failure doesn't kill two
engines at once.

At least in the Meridian they have a manual override lever which is
directly connected to the FCU via cable linkage. I know it's not
FADEC, but maybe they have a similar emergency mode in the -8.

I can't see the point of having a Twin star when it can effectively be a
single engine airplane if the lights go out.
i know someone who bought one on behalf of his club and he agreed with
me that it was a feature of the design, but insisted that it will NEVER
be a problem as long as you follow the POH. If anyone here besides
Anthony, met this guy RL, No more confirmation would be necessary that
this was a baaaaad idea.

The specific problem the crash flight had (draining the battery and
killing the FADECs) was corrected via AD requiring backup battery to
the FADEC in case you screw up the ships battery. Each engine has a
FADEC, each engine has it's own alternator and backup FADEC battery.
For that specific problem they've now put in redundancy.

Thomas Borchert wrote in
:

Bertie,

That doesn't address anything.


You're almost as funny as MX with your taking things out of context at
will. He's better at it, though.




Yeah right. nice try.


bertie

Thomas Borchert wrote in
:

Bertie,

Go **** yourself.


You need to learn to behave yourself at least to minimal standards
before any further discussion with you makes sense.


Behave myself?

Lessee, you made a national slur and you're saying that I need to behave
myself?


Go **** yourself and your sister and her donkey.

And as to dscussion, you gave up on that looooong ago. Clinging to a lost
cause is not discussion.




Bertie

Peter Clark wrote in
:

On Fri, 15 Feb 2008 13:26:01 +0000 (UTC), Bertie the Bunyip
wrote:



Hmmm, could be. Lots of turboprops have fadecs now. The latest Pratts,
I
beleive. I was having this ocnverstation with an FO who had come off a
Dash-8 and he told me the latest version of it ( Q400 or something?)
had
them. I said "yeah, but they don't have this problem with power,
though,
surely" and he told me that they probably did since power was
definitely
required to run the fadec. They tell us very little about the innnards
of these fuel units, but I cant see them icencing an airliner without
enough system seperation to ensure that one failure doesn't kill two
engines at once.

At least in the Meridian they have a manual override lever which is
directly connected to the FCU via cable linkage. I know it's not
FADEC, but maybe they have a similar emergency mode in the -8.

I can't see the point of having a Twin star when it can effectively be
a
single engine airplane if the lights go out.
i know someone who bought one on behalf of his club and he agreed with
me that it was a feature of the design, but insisted that it will
NEVER
be a problem as long as you follow the POH. If anyone here besides
Anthony, met this guy RL, No more confirmation would be necessary that
this was a baaaaad idea.

The specific problem the crash flight had (draining the battery and
killing the FADECs) was corrected via AD requiring backup battery to
the FADEC in case you screw up the ships battery. Each engine has a
FADEC, each engine has it's own alternator and backup FADEC battery.
For that specific problem they've now put in redundancy.


But the fadec still relies on electrics to make the engine run.


I knew about the AD, BTW.


Bertie

WingFlaps wrote:

I see your point and I think it's a good one. As I said before, I
smell the rat of marketing...

Cheers


You keep want to blame Marketing. Sure they may have said we need to
have an easy to use FADEC system but it was the engineers that decided
not to have the limp home mode.

Gig,

Sure they may have said we need to
have an easy to use FADEC system but it was the engineers that decided
not to have the limp home mode.


In a way, they do (if not in the way it used to be installed in the
DA42): the emergency battery. I guess what I'm trying to say is: This
engine is different than the old Lycs and TCMs. Doesn't mean it's worse.
Just different.

--
Thomas Borchert (EDDH)

Thomas Borchert wrote:
Gig,

Sure they may have said we need to
have an easy to use FADEC system but it was the engineers that decided
not to have the limp home mode.


In a way, they do (if not in the way it used to be installed in the
DA42): the emergency battery. I guess what I'm trying to say is: This
engine is different than the old Lycs and TCMs. Doesn't mean it's worse.
Just different.



What I'm trying to say is that the way the FADEC is enabled in the
Thielerts and the way it is in some newer Lycs is different. In the
Thielerts there doesn't seem to be a limp home mode.

Wingflaper or what ever his name is seems to want to take any negative
comment about the Thielert engine as an attack on the very idea of
aviation diesels and that their very nature of being new that mean old
USAians don't like them.

"Gig 601XL Builder" wrote in message
...
WingFlaps wrote:

I see your point and I think it's a good one. As I said before, I
smell the rat of marketing...

Cheers


You keep want to blame Marketing. Sure they may have said we need to have
an easy to use FADEC system but it was the engineers that decided not to
have the limp home mode.

So, how would you arrange a "limp home" mode that avoided a low volts
problem, with electronic fuel injectors?

If you go to mechanical injectors, you lose the advantages inherent in
the electronic ones.

The only way, I can think of, is to add sources of power.

Al G

Thomas Borchert wrote in
:

Gig,

Sure they may have said we need to
have an easy to use FADEC system but it was the engineers that decided
not to have the limp home mode.


In a way, they do (if not in the way it used to be installed in the
DA42): the emergency battery. I guess what I'm trying to say is: This
engine is different than the old Lycs and TCMs. Doesn't mean it's worse.
Just different.



Nope


It's worse.


Bertie

Al,

So, how would you arrange a "limp home" mode that avoided a low volts
problem, with electronic fuel injectors?

If you go to mechanical injectors, you lose the advantages inherent in
the electronic ones.


Ah, thank you!

Of course, as Bertie puts it, one could theoretically build alternative
injectors in, I guess. One could also plate the engine with gold. But, as you
say, an engine with electronic fuel injectors is an engine with ELECTRONIC
fuel injectors. The basis for the engine is a mass-production car engine.
That's what makes (may make) the engine viable in the market. And I still
fail to see how "mechanical" would somehow inherently be better or more
relaible than "electric". In fact, a common rail diesel has a much simpler
mechanical design than one with mechanical injectors - it is much less prone
to failure in that respect.

Interestingly, the SMA diesel is of the old style, with mechanical injectors.
It also has a mechanical emergency throttle. It also has gained zero traction
in the market, in large part due to its high price.


--
Thomas Borchert (EDDH)