Hi Joe;
                Glad
you got back on the ground safely. From the compression results I’d say
your prognosis is accurate. How was the other rotor? 
This is another good testament to the rotaries ability to
continue running under duress.
                I
can understand your disappointment at yet another little surprise in the air,
however it’s important to remember that even though there are a number
who have forged a path ahead of you making your installation easier, you still
are blazing a trail of your own. This is an experimental hobby and each
installation is unique, demanding that we are always in tune with the engine
and ready for anything that fate can throw at us.
                Before
each flight you gotta ask yourself “Am I ready to be a hairy chested hero
today”
 
S. Todd Bartrim
C-FSTB
Turbo13B RV9
http://www3.telus.net/haywire/RV-9/C-FSTB.htm
http://members.cox.net/rogersda/rotary/configs.htm#C-FSTB
 
 
 
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Joe Hull
Sent: Saturday, December 23, 2006 8:16 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Dead Rotor at 3000ft
 
 
 
The
weather today in the Seattle area was marginal for flying – but a nice
hole opened around my home airport (KAWO) and I was there tinkering with the
plane anyway (re-torqueing the prop)– so up I went. I did 4 touch and
goes just for a wee bit of practice and then departed the pattern toward a
bigger hole that would be legal to climb through VFR. I flew about 30 miles
northwest of the airport out to the edge of the Puget Sound and enjoyed just
being in the air. Power setting was about 4400RPM and I was loping along at a
lazy 135kts.  I turned around and headed back for Arlington and decided to
ramp up the power to ramming speed – errr I mean cruising speed. In a few
minutes I was cruising along at 170kts at about 5500RPM. Then all of a sudden
BAM – the engine stumbled and RPM’s dropped to 2300RPM.  I
immediately throttled back and switched tanks while turning toward the airport.
Altitude was 3200FT (about 3000AGL) and I was maybe 7 miles from the airport.
The engine was running real rough and wouldn’t give me more than 2300RPM.
Even with that little bit of power I ended up entering the 45 to the pattern at
about 800 above pattern altitude. It was pretty slow at the airport so I easily
made a normal landing and was able to taxi back to the hanger under power. 
 
At
the hangar I double checked everything I could from the cockpit – fuel
pressure good at 36PSI, oil pressure good at 55PSI at 2300 RPM, MicroTech ECM
showed “OK” for the size major areas it monitors. So, I shut it
down and pulled the cowl. I pulled the prop through a number of times and it
seemed that there was a couple places where I should have been hearing a
“pop” in the exhaust but didn’t. I also notice that there is
a nice ding in the prop that is about an inch long – that wasn’t
there when I left (remember I’m a pusher).
 
I
got the engine compression gage and proceeded to take the spark plug out of the
front rotor – top – BR9EQ-14. Hmmm – I don’t remember
there being a casing around the electrode – and why is that casing
sliding?  Apparently the casing around the electrode broke somewhere
inside the sparkplug and into two halves long ways down the electrode. Each
half slides freely up and down the electrode and even sticks out a little from
the end.
 
I
put the compression gage on and it looks like I get 30-30-70 when I turn the
engine over. I tried this several times and there is definitely a couple of
places where it only goes to 30. So I double check the location of that ding in
the prop – hmmm it’s exactly even with the bottom of the exhaust
– right about where an apex seal would come out.
 
I
put two new BR9EQ-14’s in both rotors and did a quick run – 2300RPM
rough is the best I could get.
 
Some
time this week I’ll go up and yank the exhaust so I can see the apex
seals – my guess is I’m missing at least one. Bummer. 
 
Joe
Hull (getting tired of little surprises in the air).
Redmond/Seattle
WA, Cozy-Mazda Rotary 71hrs