From the SoCal forum...
Hi Folks,
Yep, it was me! Who'da thunk it
Here's a rundown: we left Coolidge after the breakfast fly-in and headed
towards St. Johns (just for the sake of it). About 20 miles out from
Cibecue at about 11,500 MSL all of a sudden the engine lost power (it
was still running for a while but wouldn't hold more than about 1900rpm
then gradually faded), the CHT's started climbing like crazy and so did
the oil temp. We looked around and all there was below were mountains,
GL altitude is about 5k there (I was just thinking to myself about 2
minutes before: "we would be S.O.L. if we had an engine failure over
here"). I did a "NRST" on the 496 and the nearest airport was Cibecue,
20 miles and it is a gravel strip. There was nothing else but mountains
so I pointed it in the direction of Cibecue anyway, went through some
engine out procedures and then did a mayday on 121.5 which was
immediately picked up and replied to by a Northwest and an AA airliner
which took my location details and relayed it to ATC. As we were coming
down we spotted the US60 winding through the mountains, so that was it.
We headed for the road and had to slip it in to get down to a straight
part between 2 mountains. There were cars that were coming both ways
(but they were a couple of miles apart thank goodness). We landed on a
straight piece of road (really good landing actually, which is rare for
me) and just as we were coming to a stop 2 cars came around the corner
in front of us and stopped with plenty of room. We got out and pulled
the plane off to the side of the road where it was safe from traffic. I
checked all of the fuel lines (starvation was my first thought) and
everything checked out ok. My good friend Robbie Attaway and a few other
pilots drove all the way out from Phoenix (about 3 hour drive) and took
a look at it but they couldn't find anything either. We fired it back
up, ran it up to full power a couple of times and it ran just fine. We
got the OK from the FAA so the police stopped the traffic on the road
and I took off and flew out between the mountains! We thought it could
have maybe been some kind of icing or dirt in the fuel lines. From there
I flew all the way home with no problems
Long story short: it looks like maybe a timing issue. From what we can
guess one of my electronic ignitions might be advancing the timing way
too much (high CHT's, oil temp, loss of power all in the mater of about
a minute , no loss in fuel pressure, EGT's didn't change, changing the
mixture made no difference to anything, fuel system checked out ok) but
obviously that's just a guess, but it does seem to be the general
consensus. I have 95 hours on the plane to this point and it has run
flawlessly up until now. I am sending the ignitions back to the
manufacturer for a check over and I'm going to go through the whole fuel
system again just to be sure. It won't be flying again now until I
figure out exactly what it was that caused the problem.
If anyone else has ever had anything happen like this please give me a
shout.
I'll let you guys know what we find out as we move forward.
Cheers,
Mark - RV-7 N234C
Flying (sort of)