Perhaps this is just too simple; but we
should realize the wiring failures are inevitably issues with the “connections”.
The first thing you do with the stock CAS plug is to cut it off and throw it
away. Then make a quality soldered wire/wire connections to the shielded leads
that runs all the way to the ECU plug. One possible failure point
eliminated.
Al G
(Programming the mixture mapping
on the EC2 yet again after I found on startup that the data in controller A was
completely corrupted for reasons that are entirely a mystery. Fortunately I had
copied A to B a few days before. Apparently there is no way to copy B to
A.)
On Sun, 11 Jun 2006 22:08:28 -0700 "Joe Hull" <joeh@pilgrimtech.com> writes:
>> An
ECU that was better at self diagnoses would have greatly reduced your risk. On
your car, it would be recognized immediately.
I know I’ve taken a
little flack for my MicroTech computer…but on the plus side it did tell
me a couple of months ago that I had a “bad Crank Sensor”. Of
course, it turned out to be a bad connector - the Mazda factory pig tail coming
out of the sensor had a bad connection in the plug. It must have been
intermittent because the engine still ran fine for the most part – just a
little rough every now and again.
Good of
you to share this Joe. Can save a life.
So here
is what problem solving is all about.......but just a second, some of you are
going to have a hard time entertaining what follows. If so, just hit delete,
have a nice day. This is for the guys that responded to me privately..and
others interested.
A) When
we first heard of Johns failure, we need to force ourselves to entertain the
idea that he crashed. Under slightly different circumstances it would have
happened. We do this to eliminate our natural tendency to be complacent, to
rationalize.
B) We
force ourselves to seek the OTHER causes. Because often it's the other causes
that can lead us to lasting permanent solutions. I'll explain this better
below. So the other causes I can think of are the 5 items I originally listed.
C) We
look outside our circle. We ask:"Well, how do the automotive guys handle
this type of failure". "How do guys outside of the rotary group do
it? Etc. Now one of those solutions is absolutely PROFOUND. It has far reaching
implications that greatly reduces risk of many historical failures.
Let's
back up a little bit. Johns ECU saw the time interval between crank pulses drop
in half. Meaning the rpm went from 6000 to 3000 in 100 ms. Physically
impossible. Only a crank sensor fault can cause this. Realistically, the ECU
probably saw this weeks before his incident. Maybe hours before. But it's the
nature of most wiring faults to occur that way. Not all of them, one of the
crank sensor failures resulted in crash with almost no warning.
There is
a huge difference in flight risk if the ECU sees this fault, tells you immediately.
You land, you focus on the real cause, you don't have to think "Maybe it's
my muffler or mixture that gave me that little pop. Maybe it's a spark
plug".
A key
universal truth, is that risk is always reduced if you shorten the delay in
notification. Each day Johns connection got a little worse and there was no way
for him to know.
So we
decide "I want the ECU to be smart enough to tell me when the crank sensor
develops blip." Our risk is reduced substantially. Then we think about it
some more. Crap, you know that guy that had almost crashed a few months ago due
to loose buss connection? That was same failure pattern. His airplane likely
saw a momentary voltage drop minutes or hours before he headed to airport. So
we say:"Hey, I want my EIS to respond to dips in voltage, so I get advance
notice of those faults too.
So you
put this solution in place, and you have made every plane less risky. Even
though some of the wiring faults will still occur. You've now reduced flight
risk.
-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html