Think about this folks, what Paul is doing with the PC solution is far
 superior to any of the automotive units. He will potentially be providing
 users with capability to interface all of the functions of the aircraft,
 directly on the instrument panel, not just the engine, or monitoring flap
 angle, airspeed, etc. But we would be able to use it to control
 everything,
 even flying the plane remotely, or with auto pilot operated from the PC
 board; just on one of these small fast PC board setups. Imagine getting
 into
 your craft, turning on the ignition, and looking at a 15" computer monitor
 that you built into your dash, and seeing hundreds of data streams on
 display, access to pinhole mini cameras mounted in you cowling, or
 anywhere
 else! This is transformative, it is revolutionary to the experimental home
 built industry. I truly hope some of you programmers join in with Paul to
 make it a reality.

 Ed Carver

 Racing Beat sells and supports the Motec unit and it is a very good unit.
 Price however is about $1,800.

 Thanks Ed for your understanding on this issue. I might also point out
 that
 there are some very sophisticated moving map programs out there that will
 run on the same type of PC mother board and hardware. Some show the
 terrain
 you are flying over in 3d with all obstructions shown so this is a

 monumental advantage in low visibility conditions.
 http://www.navzilla.com/

 I wrote my first articles for Kitplanes on this subject back in 1988 1989.
 The Home Built Glass Cockpit by Paul Lamar Kitplanes June 1988 page 69 The
 future can be here now: electronic instrument displays in your homebuilt.
 Glass Cockpit: Part II by Paul Lamar Kitplanes January 1989 page 66
 Automatic position reporting could be helpful when pilot's hands and mind
 are full.
 Paul Lamar HEY PAUL!!!!!!


 I just felt saying THANKS A LOT FOR LETTING THE REST OF TAG ALONG FOR A
 GREAT RIDE!!!!!! [YOU'RE THE MAN!]
 Gene Kahn

 Here are some pictures of my late 1980's glass cockpit in the C182 with a
 8088 mother board. Updated the map every second written in QB under DOS no
 less. I would use QB again and DOS if it supported USB but it won't so
 Linux
 and C it is.

 Paul Lamar

 Paul,

 1201 seems an odd squawk code!! I never had one that close to 1200 when
 assigned by ATC. :-)

 Bill Schertz

 Yes I don't know what was going on there :) Judging by the altimeter
 and throttle I was at 10,000 feet.

 Paul Lamar


 The big boys are actually doing this one right. Independent boxes for
 each function. Dual (or more) displays which can select data from the
 various boxes. Necessary inter-box communication could be handled via
 Ethernet or similar. Fault tolerance designed-in. I don't want the
 engine to quit if my GPS starts sending out unpredicted bogus data.


 Matt-

 Matt,


 You don't want it to become a Toyota in other words? I suspect o2 sensors
 have a part in their issues because of the way o2 sensors fail.

 Bruce


 Bruce?
 Are you saying that a rich mixture caused by a failed O2 sensor
 can cause unintended acceleration?


 Paul Lamar


 Paul,

 It's hard to say without knowing how they programmed it and without
knowing
 the exact characteristics of the newer o2 sensor used but I had a case a
 long time ago where I was doing some work as a consultant for an OIL
 company
 in CA. They instructed me to program a steam generator with O2 mixture
 control using full control. I argued that it should only be trim control,
 or
 a narrow band not the full range due to the failsafe of the o2 sensor I
had
 to control off of.

 They wouldn't give in so I quit. Later they had an
 accident where the operator had lifted the heated top off the sensor
 causing
 it to cool like it would if it failed, thus the signal went to low scale
or
 4 mA indicating high o2. It caused the controls to see the mixture as lean
 or too much air to fuel. The gas flow was controlled by the operator
 manually and remained the same whereas the computer controlled the air via
 an air dampener so it closed the dampener all the way rather than a
 percentage as I had argued. The operator seen the black smoke, panicked
and
 threw the top back on the o2 sensor which opened the air dampeners to the
 full position with a load of hot natural gas waiting in the burner and the
 generator exploded and injured or killed the operator. I heard about it
 about a year later.

 I understand in autos, they supposedly don't use o2
 control in the warm up process until it's fully heated up, then they
switch
 to the signal or so I'm told. Depending on how they programmed the ECU,
and
 if they used full o2 control rather than limited or trim control, and if
 they didn't consider safeguards and failsafes if the sensor fails or
 appears
 to fail or loses signal (an open or a short), and depending on the action
 of
 the controller and the medium that is being controlled, if they are
 increasing throttle position rather than decreasing fuel to maintain
 mixture, they may have programmed in a run away condition without knowing
 about it.

 Now I'm doing a lot of supposing and remembering here because I have never
 studied the newer o2 sensors and which way the signal react but other than
 cruise cruise control, I can only theorizing that they may have somehow
 used
 mixture control for economy control at high speeds without taking into
 consideration the o2 fail safe reactance.

 The question is, when looking at the o2 sensor output of today, does an
 increase in air (21% o2) give a high value/voltage or a low value/voltage.
 What does zero volts represent as to o2 if you happen to know? On the old
 units, zero or 4mA represented 21% o2. Low or no heat to the sensor causes
 the sensor to appear as high o2 (21%). I hope I have this all correct,
it's
 been a long time but it was burned into my mind at the time to always
 double
 check everything if doing any mixture control based on o2 sensor signal.

 It's been a long time since that incident with the oil company and I'm not
 sure if the o2 sensors have changed today but these had a reverse signal
as
 I recall. When the heater for the sensor failed or if the o2 sensor
failed,
 it also showed high o2 (low signal) rather than low o2 (high signal). When
 we have a negative cofficient like this we always need to anticipate every
 condition and every variable to be failsafe even to the point of using
 double or tripple redundancy.

 I'm not sure about the new automotive sensors and I'm not sure how they
 programmed it, fuel or air, as the output control but I suspect since the
 throttle is opening or appears to be opening, like cruise control calling
 for more throttle, to maintain speed, I would be looking at cruise
control,
 or o2 control as a possible culprit. Not many things are connected to the
 thottle on a car. Since Toyota apparently isn't finding their problem, it
 could be they are not digging deep enough to look at failed sensors or
cold
 sensors (water maybe splashing on them perhaps) or something giving them
an
 intermittent failures that isn't being reproduced in testing. Just a
 thought
 but often I see people take something simple for granted and assume the
 signal is like most things or positive cofficient.

 I could be totally wrong on this since the technology has changed a lot so
 I
 wouldn't bet a ton of money on it. I'm going by info from a long time ago
 trying to connect dots of today that I have no real info on.

 What can you see in this, you may have some inside knowledge on the
 Toyota ECU black box and how they control. It would be nice to know for
 sure. I hope this makes sense.

 Bruce

 I was an expert consultant one time in a unintended acceleration case.
 Turned out the block water temp sensor failed increasing the idle
 speed. The driver jerked the shift lever into reverse and the
 car took off backwards in a parking lot killing the person
 walking behind the car.

 Interesting you should bring up cruise control. I can see how a failure
 in the cruise control can bring about unintended acceleration.

 Of course anytime you have a computer controlling a system there
 are a zillon possibilities for failure. Could be a bug. Could be an
 alpha particle changing a bit in a memory location. One bit change in
 any of a 8 gigabits of program memory could create havoc.

 There is a device called a watch dog timer that resets the
 computer in a run away program situation. The programmer is required
 to insert the watch dog code in the main program loop. If a sub program
 does not get back to the main loop in time the watch dog code
 resets the computer. If the watch dog code or timer fails than anything
 is possible. In an aircraft situation the pilot is instructed to
 manually reset the computer in certain circumstances.

 It is going to be interesting on what is causing this if it is real.

 Paul Lamar


Paul,

Yes I'm very interested in the outcome that is if they tell us the details
and tell us the truth. I always felt Toyota was a good product but as you
say, some little thing can cause a great deal of damage and bad publicity.

They really need to look at any process that has access to the throttle
whether it be idle speed, cruise control or emissions control. Now that
they
run it all through one ECU, it is all suspect. In industry, we can have the
best controls, the best intentions but when we have a lot of different
people with their hands in the same pie, things get overlooked or shortcut.
When you have one person who owns the project, he is more apted to test
every iteration or a process to make sure he didn't forget something. But
one never knows.


I once had a really good A&P ask me to double check his
work. He had replaced a Cessna wing tip and couldn't get the nav light to
work again. He finally asked for a second opinion. A new set of eyes seen
that he had no provided a ground wire to the light from the wing. The
tip was fiber glas and didn't conduct electricity. He was really kicking
himself when I pointed it out. It was too simple. We had a good laugh about
it after I rubbed it in.

Also do you remember back when there was a broken motor mount issue on some
cars before they began using a sheathed accelerator cable, they used a
mechanical linkage. On some cars, if a certain motor mount broke (I think
left) , and if a person accelerated too fast and/or if they applied the
brakes at the same time, the engine would actually torque or raise up,
opening the throttle wide open until it stabalized. The more you held the
brakes the worse the condition got.

As a result there was a lady approaching
Kentucky Dam, apparently used both feet to drive, applied the brakes
without
letting off the gas, the engine raised and went wide open. They said the
brakes and wheels were red hot as she crashed into the concrete abutments
of
the dam. It was not a straight approach but a curve on the Eastern
approach.
It seems like it was back in the 60's or early 70's.  Sorry to get off
track
but they are things we always have to be concerned about when building
things.

Yes the watchdog is a check if the processor goes brain dead or gets caught
in a loop somewhere. It used to happen a lot. Microsoft had a lot of issues
with that and could not be relied on for realtime industrial control. Was
that your experience too?

Bruce

Well the main problem Windows has unlike Linux there is no real time
version.
I think MS has finally implemented watch dog timers.


Paul Lamar


Paul,

Yes I often compared MS Windows to Tammy Fae Baker, a lot of makeup to cover
up a lot of ugly. :-)
I just had problems with Windows 7 that I just got. One would think that it
would be almost perfect by now.
Most industrial computers use some version of the Unix platform and prove to
be very reliable.

I have Linux on one of my machines. I should use it exclusively.

Bruce