I agree that it sounds like electrons Bobby. An open CAS would cause instant shutdown but I've never heard of a Mazda CAS going bad. Have had reports of bad Subaru CAS's.
BTW, apologies for the confusion about your fuel system. I was confusing you with Sam Hoskins who also had a recent power failure. His sounded like fuel system problem but no further word from him.
Tracy Crook
Sent from my iPad
What was the system voltage during run up? At what voltage does the EC2 shutdown? Not a likely candidate.
What happens when the CAS circuit goes open? Does the EC2 stop firing?
Will a exhaust blockage of ?% stop the engine completely? Steve's testing showed a partial blockage has a major effect on power. Bill's muffler had to be full of crud for that much to end up back in the engine. If the HP2 lower cone was partly intact and came loose then a major blockage is very possible. It would trap all the little pieces that had been collecting in the muffler. My first HP had large chunks of cone still intact along with all the little pieces. My second HP seemed more intact when my incident occurred. Meaning less large chunks appeared to be loose but plenty of the small crud. The outlet cone was loose but more intact. I had hoped that moving the second muffler to the belly would extend it's life but it didn't. In fact it may be more dangerous since the small pieces can't be discharged as easily. My under cowl muffler was mounted at a downward angle. Belly mount is almost flat.
I agree Ed that electrons seem to be the most logical cause but may be impossible to validate.
Bobby
Sent from my iPad
We still don't know (and may never),the causes, but
Sam's and Bills incidents based on initial information would appear to me to be
two different causes.
Sam's engine kept running - although sputtering
and producing no power - this to me sounds like a fuel related problem (possibly
vapor lock, possibly something else - could be muffler blockage). Bill's
on the other hand quit suddenly and without any warning - that to me sounds more
like an electrical problem - either the firing pulses to the injector stopped or
the spark stopped.
If I were Bill, I would use the EC2's diagnostic modes to
check out each circuit - if one doesn't check out then that is probably the
answer. If both check OK then more head scratching.
Ed
Sent: Saturday, September 03, 2011 9:43 AM
Subject: [FlyRotary] Re: The good news and the bad
news......
Bill,
I'm sorry to here about the damage but glad you weren't injured. I don't
know at what percentage of exhaust blockage the engine would stop running. Also
no reports on the condition of Sam's HP2 muffler. Three aircraft experiencing
very similar problems this year is too many. If you have leading /
trailing plugs and primary / secondary injectors on separate power feeds then it
should have kept running. That leaves fuel delivery (vapor lock), CAS circuit,
Controller power, A side computer issue or muffler? I believe Sam did switch
controllers during his incident. I didn't and had plenty of time to do so. It's
now the second item in my emergency flow.
One common item can be eliminated be removing any muffler that has packing.
Especially Hushpower 2 since they are common to all three incidents. I'm
assuming Sam's muffler also had loose internals.
Bobby
Sent from my iPad
I have been
holding up reporting this until all the facts are in, but that might never
happen, so here we go.
Good news: No injuries.
Bad news: I have some work to do.
Photos at:
http://www.tiny9.com/u/2101
On August 16th at 10 AM, I
lined up for takeoff at my home airport (3600' paved) into a 5 knot
headwind. I had just finished changing the oil and filter and
plugs. Run-up was fine, so off I went. Approximately mid-field,
and a couple of hundred feet in the air, it suddenly and without any warning
became very silent.
Hit the big switch which puts direct battery power
to everything engine, but no noise. No more time. At this point
flying the machine becomes THE priority. Dropped the nose and was amazed
to see a little bit of runway under the nose! I had fully expected to
land in trees, houses or the river, so I dove what seemed like straight down
to capture as much runway as possible while (somehow) holding the electric
flap switch long enough to get full flaps (noticed this later). Pulled
probably my best round-out ever - no bounce. Brakes to max and tail up
for weight. I think my sub-concious put it all the way on the nose to
try to prevent going through the fence and down the hill. Wheel skid
starts about 200 feet from the stopping point. Skid marks from the wheel
pants, cowling and prop run about the last 50 feet. It stopped nose down
just off the end. The tail was still over pavement. Pushed the
slider canopy UPHILL, stepped out and down. Noticed that I was not even
scared by the whole event. Interesting. Never even considered
trying to turn around. Pre-thinking that non-option apparently paid
off.
More good news. No FAA or NTSB as it was a
non-reportable incident. Didn't even bend the gear legs. Also, my
neighbor crashed in a Challenger about 10 minutes earlier at the city airport
about 10 miles away. The police and rescue types were headed that way
(they had injuries) and were not interested in my minor mishap.
As for
the engine. When we got it back to the hangar, the prop would turn only
haltingly. You could feel grinding going on inside. First try at
turning had it come up hard and stop. More fooling with it and it
gradually came looser and would turn. Really looked like something came
loose in there. Pulled a plug from each rotor and did a compression
test. Rotor 1 was 80-80-80. Rotor 2 was 2-2-2. More proof
that something had come loose. With that evidence, the insurance company
allowed me to remove the engine for inspection. What I found was a pile
of ground up ceramic junk. All the seals were still fine. Lots of
time went in to finding where that stuff came from. Went through every
inch of the induction system. Finally Jason Hutchison (my other
on-airport rotary guy) broke the code. While the RV was standing on it's
nose, this crap from my burned-out Hushpower II ran back up the manifold and
in the exhaust port. That is what was grinding. Crap. Now
the entire thing is off the firewall including the engine mount. All the
wiring is disconnected (did not find anything loose or missing). I spent
the morning looking under the panel for any loose or broken wiring, but found
none. When I get the EC-2 out, Jason wants to plug it into his plane and
we'll do the plugs and injectors test. If that checks out, Tracy, it is
coming to you for a good look. I don't know what else to check.
The engine quit just like somebody reached over and turned off the
ignition. No stumble, no hiccup, just instant silence. I honestly
do not know if the prop was turning or not. I suspect not, due to the
silence and the fact that one blade is untouched.
As you can see from
the photos, there was something going on with Rotor 1. Wear is apparent
down stream from the plug holes and all 3 apex seals are starting to chip in
the center. There is quite a lot of carbon also on the rotors after 170
hours.
Going forward, I have decided to look at resale value for
if/when my RV-12 days arrive. This means putting a (gasp) IO-360 on
it. The rotary has given me a safe 10-year run (til now, of course), so
I have no regrets, but this is an opportunity to make some changes, and parts
are already on the way. I will still be hanging out at the engine tent
at S-n-F and wherever else gatherings happen. Hope to be flying by the
first of next year....
I'm sure some of you will have suggestions about
what might have gone wrong, and I welcome any kind of speculation, but bear in
mind I am just looking at a pile of parts and wires at this point. Both
fuel pumps were on, tanks were over half full, crank angle sensor worked
fine.
Guess it's obvious that I now have a RD-1A, EC-2, EFI Monitor
(Ed's), Felix 68/72 and Props Inc 68/72 wood props and LOTS of engine
parts (my whole 14-year stash) available! And priced to sell!
Bill Eslick
RV-6 13B/NA EC-2 RD-1A
750
Hours
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