It   seems like fly-by wire is the current buzz   term.

And the  advantage of  the throttle-by wire is??????,  in   aircraft
applications.

Having been  the  recipient of a  possible  throttle jamming incident in the
air,  with a  linkage  that did not  give me good feedback of  the  actual
connection   of the throttle  and the  throttle body,  unless there is a
really   good
reason,   other than "that  it is available",  in  aircraft  application,  I
think  I
would rather go with  the push-pull  direct connection  variety  of
control.

Someone please straighten me     out

Rich

--

Rich, This is not to "straighten you   out"  but  it's why I'm would like to
at least give it a go  at  doing   this.

Push/Pull direct connection is very  nice,  particularly when  it's  to an
engine just up front  of you,  however sometimes the engine  like in  my
case is  behind you and  the cable runs become quite long. I  need have   to
have 2  throttle controls linked together, it's a Tandem   Machine and   I
need enough space for people like me - 2 metres  tall,  6'6" in  the  old
measurements.

I really hate  having connecting   rods on the left  side of the seats  like
some others have done and  the  machine is pretty   open. If I use a rod
system to join the  throttle  controls then  it sits out  in the open, is
easily  damaged or tripped   over and makes it very hard to  get in/out  the
left side of  the  machine, I would really like to able to  get  in/out  the
left side of  the machine. So to avoid this issue  and I  really  want to
avoid it, I  need use at least one   push/pull cable to link the  two
throttle levers  together  so  they operate together and then  another
cable from one  of  the  throttle controls to the throttle body, now   I'm
certainly able  to  do that and if the electronic control  does not  work
then I  will be  doing just  that.

However, TK insists that he  really  wants to  test  his throttle
controller design. He is also pretty    certain that it  will be perfectly
reliable, so one must give a  fair  go  after all, I  originally asked him
what he  thought. He got  interested in  doing  this, it would not be  very
fair not to give  a fair go. If it works   and I have  no reason to doubt
that it  won't then why not? For others   it  simply gives another  option
for a throttle control system.  I'm  already  completely  reliant on all
sorts of other  electronics and  electrical  systems  for flying using
an  RX-8 Engine, for instance  Tracy's  EC3, Tracy's EM3,  fuel  pumps,
trim system etc.

Apart   from anything else it is  just  plain fun to see if it can or  will
work  without  spending too much time or  money on it, we've  only spent   a
couple hours on it so far, I suspect that  it will  go to  a  working
prototype with only a very few more hours which   is  pretty  good, it
would more than likely have taken me  at  least several hours   working out
how and where to run  the  push/pull cables as well as in   fabrication time
of a  number or  brackets and the like and to make sure  that  it  would not
get  damaged or bind going to the engine keep water   out of the  cables
etc.

Regards  David

--

Greetings  David.

I am  also of the  rear engine persuasion (aero canard SX). The  length   of
the
cable is somewhat immaterial. It's been used in boats   (much  longer run)
for
years, as well as virtually all twins, each  of   which has  longer and more
tortuous runs.

The  tandem  throttle  arrangement does create some problems, but  not
unsolvable  with cables.  Merely run one cable from the front  lever to  a
fixture  at the aft  throttle control which  connects this front  cable to
the
rear cable (kind  of like a  union with a perpendicular  bolt to engage the
aft throttle  lever.  This fixture (union) can be as  simple as  the
arrangement
used in the  locking mechanism of the  canopy,  or as sophisticated as  you
like.

With this  arrangement,  the forward throttle is directly  connected to  the
engine,  albeit through the fixture.

The cables can  be  routed any  way you please.
Good cables are lubricated, can be bent  and   give a sturdy attachment.

This gives tactile feedback with   the  throttle. Even the Airbus which is a
FBW craft syntheses  feedback  to the  pilot.  Direct  connection,  indeed,
tells you  throttle plate  position, binding and a  myriad  of things  which
you
can't get with  wire.  Perhaps some feedback  information  forewarning   of
some
possible impending  malfunction (a bad place to  have   one)

If You use TK's EC2  or 3, you have  redundancy in spark, in go  juice, but
absolutely no  redundancy  in throttle position nor feedback  information,
or
even   function.

Please don't get me wrong, I  really  want to use  the fly-by wire but I
need
more info before I trust my   Glutei  maximi to it

Rich


--

Hi, Rich - I'll try   to  keep this shorter this time.

Agree the cable length does  not  really  matter. Tandem Throttle link-up
was always going to  be cable.  The Throttle  levers are designed for it,
so I'll use  it. Good Cables  are the only ones  to use :), Cables can
routed  anywhere within reason  but, wires are much  more flexible,  the
limitations for cables are  bend radius which forces some   space & minimum
distance limits.  Wires with the Throttle body  have  basically none.
Tactile feedback in  this really comes from  friction which  is built-in to
the throttle  levers I'm using  already. There are thousands  or millions of
these  style or  throttle systems in use today all around the  world. If
the
throttle body was already designed for a cable, I simply   would  use it
without a second thought.

Tracy Crook    (http://www.rotaryaviation.com) is the designer and seller
of the EC3   &  EM3.

T.K. is a friend of mine that used to work up  until  very recently  in R&D
in
the Auto industry  designing and  developing this sort of  stuff, He want to
do this  now, I have have to  give the fair  go.

Regards  David


--Hi David,

I  mistyped.

I meant Tracy  Crook (TC) but used K instead of C. I  agree with the
limitations of  the radius of the cables. When I referred to  tactile, I was
referring  not specifically to the resistance of the lever,  (as  you
correctly
stated a product of the friction), but the  mechanical  awareness of the
connection to the butterfly and it's  actual position. With  FBW, it is
possible  to
think that you  have full open throttle  (because of full throttle position)
and  actually have the butterfly (or  whatever you use to shut down  the
airflow)  closed giving you one more  totally unknown in the  event of an
engine
problem.  Unknowns eat up  valuable time  when attempting to troubleshoot an
engine problem  at  low  altitude.

Case in point:

As I was approaching Peoria, IL   about 4 years ago, in my dragonfly, less
than 1k AGL, my engine did  not  respond to advancing throttle. The linkage
that I  used was  a  cable(high quality) pulling against spring tension. The
spring  opened   the throttle. the cable closed it. Seemed like a good  idea
at the
time. a  cable  snap would yield a fully open  throttle and a pull only
cable
could be bent in a  smaller  radius.

Descending for my  approach to KPIA, upon leveling off, I  advanced the
throttle, The lever  felt normal, but the engine  continued to idle. I spent
precious time trying  to trouble shoot and  correct the problem. The episode
resulted in the  plane's destruction  and my survival landing on the only
area,
way too  small for a  normal landing with a 40K tailwind with berms and
farming  implements  at what would be the end of my rollout. Not a good
scene.  The
only  other place was into the wind on a freshly plowed wet field (did   I
mention  it was rainy?)

Post accident (incident)   investigation revealed nothing wrong with the
engine of the linkage.   However, Post Post inspection (after dragging the
corpus
home)   revealed that a heat shield may have distorted with heat jamming
the
throttle closed. (Idle) and when I added throttle, the relaxing  cable  had
no  effect since the spring tension was now  counteracted by  friction to
the
heat  shield. I had no idea of  this since from  throttle position and
friction all  appeared  normal. After "arrival"  and cooling down, the heat
shield
returned  to  it's normal position  and the throttle worked  correctly.

This is not to justify the design  error but to say  that a solid throttle
connection would have notified me  immediately  that the throttle was
jammed,
or  possibly given me the  ability  to muscle open the throttle yielding a
totally  different   result. This event happened after 100 H TT.

Had I been aware that  the  throttle was not opening, or going to open,
perhaps I would not  have wasted  the precious moments trying to
troubleshoot and
would  have been able to put  it down in a more hospitable place I  had
passed.

When you have an  engine failure at low altitude,  although time flows like
molasses, every  second is  critical.

Rich

An electronic throttle needs a computer  to  control it.
What happens if the computer goes insane?   :)
http://www.fear-of-flying.us/index.php?p=1_11_The-Robot-Plane
It  can  kill you long before you can do anything about it.

Current  airplanes  have carburetors, magnetos and throttle cables for
very  good  reasons.

Paul Lamar


Paul,

Just to show  that I can argue on both sides of the issue:

Current aircraft engines  are now going to fuel injection Large  aircraft
engines have all gone  to fuel injection.

Electronic FI and ignition will be commonplace when  certifying new engines
becomes, once again, financially viable.

50  or more year old technology will ultimately yield.

Many of the things  in certified aircraft are there because that's the way
they were certified  in a different era and the cost to re certify, at this
point  in time  is prohibitive.

Will pistons ever disappear in favor of the "rotating  wobble" --  perhaps.

At this point, I still like a solid throttle  connection.

Rich

Are you picking nits? :) Should I have said  >>MECHANICAL<< fuel injection?
:)

Which aircraft engines  are going to EFI?  MECHANICAL fuel injection
has been available for  years.

Put this string in google and see what you get "Electronic fuel  injection
on aircraft engines". Nada :)

BTW Wankel rotary engines do  not  "wobble"!!!!

http://www.rotaryeng.net/how-wank-works.html

"Many  engineers and mechanics that should know better still think the
rotor
translates, reciprocates or wobbles in the rotor housing. Nothing  could be
further from the truth."

Paul Lamar

Nit nit nit.

I was metaphorically speaking with the wobble. I am well familiar with the
movement of the rotors in the trochoids.

At this point there are no aircraft engines with EFI, and darn few that
have advanced from old old old technology. When bucks become available for
development, or the FAA changes the confiscatory method of certification, you
will see these things come to the market. Economy and fuel prices will
demand  it. It and electronic ignition will probably be a centerpiece for single
lever  control.

Rich

I disagree.
Don't hold your breath. The incentive is just not there to replace what
we have now. There is little or no fuel saving potential over mechanical
fuel injection. Perhaps if piston turbo compound catches on they will need
a computer to control it. The over whelming advantage of the current
aircraft engines is they still run with total electrical system
failure. Also don't underestimate them. They may look old but
they are highly refined with near the best material available for
an excellent power to weight ratio for a piston engine. There have
been half a dozen efforts to replace them with different technology
in the past 20 years and all those efforts have failed including the
side port Wankel and the water cooled Continentals.
The Wankel will never be viable unless p-ports and turbo compound
are adopted. The current advantages of the side port Wankel are just
not enough. I thought it was going to happen 11 years ago when this news
letter was started  yet it did not. If the Wankel is ever going to catch
on its greatest advantage, namely the better power to weight ratio, must
be taken full advantage of. You are not going to do that with side ports.

Paul Lamar