Chapter 29 - Flight Testing part 5

Taking care of Squarks

Next cat I get, I think I'll name it squarks. Speaking of cats, I'm starting to like the "Slick Kitten" name. I might even paint it on the fuselage. It'll look good parked next to "Cat's Meow" at Rough River.

I used the old AC drier for an oil catch can. It already had the 1/8 npt holes I'd drill when I used it for calibration. Any oil blown out of the breather tube goes in at the top. At the bottom I used an old brake pipe fitting with 6 inches of clear brake pipe to let me see the level. I found a spot for the can on the firewall and attached it with a rubberized clamp. Finally I added an overflow which lets out into the bottom of the cowl (on the cold side).

I picked up a $10 pneumatic spark plug cleaner from Harbor freight and used it to clean the very black plugs. It seemed to do an excellent job, so I put them back. I'm thinking that these plugs hadn't been cleaned since Tracy was down here a couple of weeks ago. The mixture is much better, but it's still rich at low rpm and the plugs still get fouled. Maybe the plugs were causing the rough running at low rpm.

I swapped the oil temp sensors. The one in the line to the redrive was the one for the analog gauge which was reading high. It's mounted on a rubber pad on the redrive plate. Perhaps it's getting some radiant exhaust heat from the turbo shield. If the EM2 shows high next flight, and the analog gauge is normal, then I'll know it's a radiant heat problem. If it's the other way around I'll know it's a calibration problem.

The adjustment bolt on the blow-off valve was 1/4 inch, if that, away from the cowl, and was touching when the engine moved a little at different power settings. That was easily fixed. i found a shorter bolt. At the other side, I rotated the vacuum regulator on its fittings to increase the clearance.

I took a real close look at the main gear and the wheel pants to check for possible damage after the fairly firm touchdown I'd made. No problems that I could see. I need to tighten the nose wheel axle bearing a bit more and the nose wheel damper to get rid of a bit of a shimmy between 40 and 30 kts when braking. After that the only remaining work is to refit the upper cowl and clean the canopy. Hopefully I'll get to that tomorrow, which is supposed to be a rainy day, and will be ready to fly again Saturday morning.

Slick Kitten 2

Saturday morning I tightened up the nose wheel a little more, installed the cowl and went flying. The plan was to do a few circuits, land and check that the catch-can was dealing with any oil issues, then go back up for a longer flight.

The pattern was chock full of aluminum. I was at 300 ft on final when a pile of it (aluminum, that is) pulled onto the runway for takeoff. Geesh. I buzzzzzed over his head and went round again. My second approach was a dogleg to give a Cessna time to get down and clear the runway. When I was at 100' on short final he was still taxiing slowly and a ways from the turn off, so I went around, again, this time flying the runway at 100'. I think Paul & Al were enjoying this from their ringside seat on a golf cart. I turned my landing light on in the nose for better recognition. On the third approach I had the runway to myself, got it down to 80 kts and gently sat her onto the mains. As I rolled out with the nose still off the ground an unknown voice on the frequency said "Nice landing, Cozy"

The oil pressure and temps were good for the entire flight and everything seemed smooth - dare I say it - normal. This time the EM2 oil temp was higher than the analog, so my sensor is definitely getting heat from the exhaust. Back at the hangar there was some new oil on the cowl. I took the cowl off and hunted for a source with no success. The results, however, were easy to find. Just about everything had a thin film of oil on it. Probably doesnít add up to more than a 1/4 cup, but its getting everywhere, including hot places. Obviously the long flight was cancelled for today. We backed her out of the hangar and Al leaned over the wing to inspect all the fittings while I ran the engine. It's hard to be sure, but we think it's seeping out between the block and the mount plate at the front right side. RTV won't work with the plate at 180F, so I cleaned it off with brake cleaner and sandpaper, then left it to cool. This evening I'll put a bead of RTV along the join and let it cure overnight. While short, the flight had been pleasant. The idle is still rough and a bit high. I find that I can get a much smoother idle on the ground by disabling one set of injectors. The brake shimmy is still there, the EM2 is bitching about the voltage being 14.3, and I still have an oil leak, but still - it was fun flying the pattern and there's now another 0.4 on the hobbs.

The Value of Mail Lists

Saturday evening Char & I went down to the hangar and she passed tools while I cleaned up the area with brake cleaner, air and sandpaper, added a bead of red RTV and left it to cure. I rested on Sunday. ok?

Monday was 70F and blue skies, a beautiful day for flying. I headed to the hangar determined to beat Paul Conner's score of 3.5 hrs the day before. Before pushing out to test the oil leak fix I decided to follow through on discussion on the rotary list and see if a leak in the intake system might be contributing to my idle problems. I removed the manifold pressure fitting, hooked up the air hose and regulator and pressurized the intake to about 25 PSI. Of course pressure was leaking through the engine and back through the intake system, but there was enough residual pressure for me to feel the cool air escaping from one side of the throttle body gasket where it attaches to the manifold. I removed the throttle body, realizing that the new RTV would need to cure overnight, and my flying for today was cancelled. Damn. An hour later the TB was reinstalled with new RTV and all the safety wires replaced.

Now I was stuck - perfect weather and wet RTV. Discussion on the Cozy list had reminded me that I hadn't checked the brake cylinders for about 3 flights. I removed the cover and found that the right (Char's) side was 1/2" low, and there were signs of fluid on the floor below the cylinder. I checked around and discovered a less than fully tight brake pipe connector. I tightened it and replaced the missing fluid. Good catch. Thanks, Carl. Reading the flyrotary list, Cozy list and the canard aviation forum every day takes up a lot of time. Today's finds prove that it's worth it.

Next time I run the engine I have a couple of things to try on the EC2 tuning to adjust the idle. One is to raise the staging point a little with mode 7 so the secondary injectors don't fire at the lower manifold pressures. The other is to adjust the mixture manually in mode 1. If these don't work it's been suggested that I try swapping the primary and secondary firing circuits. Apparently rough running idle is a common problem. As Ed says - the rotary is so great, you have to beat it with a stick to get it to slow down.

A Disappointing Day

I borrowed the title as a tribute to Steve Brooks, who's moved to another state and has to drive 600 miles to flight test his turbo rotary Cozy IV. Today Steve had a fuel injection problem that forced him to stay on the ground. He reported it as a "disappointing day" Disappointing isn't a word I'd use in that circumstance. More evidence of the sheer tenacity needed to get this done. Meanwhile, back in Palm Beach, I was sitting in my plane with 20 gallons of additional gas on board, the cowl on and ready to taxi. First I wanted to adjust the EM2 voltage limits to get rid of the spurious flashing voltage warning. The flashing is with a voltage of 14.2. The high range is set at 15. I bumped it up to 16, which is way more volts than I want to see, but hopefully will get rid of the warning.

garbage data While messing with the EM2 I thought to check the graph of injection pulse widths at various MAP settings in the hope of seeing something I could adjust to fix the idle problems. When Tracy came down here and first pulled the graph up it looked like random garbage. good dataThat's how it looked today. Alternate bars were ranging from zero to full scale like the graph on the left. The graph on the right is what it looks like when its programmed sensibly. I called Tracy, but the line was busy (probably Steve). Twenty minutes later I got through. Tracy thinks it might be noise on the program store line or a bad ground. I'm beginning to wonder if it's a bad chip or internal connection.

The good news is that the engine seems to run fairly well on garbage data, and I do have a backup controller, so I was still considering flying with the restored default settings, if only to see if my oil leak has gone away. Interestingly, Steve is chasing a similar oil leak too. This is where things started to go bad. My preflight checks include the landing brake. It's down, and for the first time since I fitted it, it won't come back up. The fuse is good, and the LED (which takes power from the switch) is working, so it's got to be either the relay or the actuator. Unfortunately the relay is fairly well hidden under the IP cover. I removed the cover from the actuator and found my voltage meter. The red probe had ripped off the wire. OK. This is good time to test my new "cold heat" soldering thing I bought from a TV ad. Twenty minutes later I junked the cold-heat gun and used my propane solder gun to get the job done. Another $30 down the Swannee. I tested the voltage at the actuator. Nada, so it looks like the relay or the switch.

At that point I packed up and drove home (6 miles) in disgust thinking of Steve and his 600 mile trek. I'll come at it with a better attitude in the morning.

Another title I considered for this entry was "72. Skies of blue. No F'ing joy with the EC2!"

Switching Switches

I have a suggestion for every builder who hasn't done the wiring yet. Drop in at Radio Shack and pick up a couple of their neat little microswitches. Then, on the way to the hangar, stop in at home depot and get yourself a large mallet. When you arrive at the hangar, put the switches in the middle of the concrete floor, stand back, then hit them really hard with the mallet. This way your resolve NEVER to put radio shack switches in your airplane will be firmly stored in memory.

The first thing to check on my landing brake was the switch. I'd installed one of those neat little Radio Shack microswitches to control the relay. I used this type mainly because it matched the one supplied with the electric nose lift which was next to it on the panel. I tried to undo the little nut, but it wouldn't budge. It seemed to be corroded in place. Eventually I cut the nut off with the dremel and pulled the switch out from the back. There was power on the center terminal, but nothing on the "up" terminal. I replaced the switch with a big clunky airplane switch, and the landing brake worked fine. I looked at the nose-lift switch suspiciously. This one came pre-wired with the Williamson gear. I undid the nut, which moved easily, and the switch pole came out in my hand. Talk about a problem waiting to happen. If the switch had come apart in the up position my manual lowering tool would get the gear past the microswitch, then it would come up again electrically. I'd have to disable the electric to get it down. Interesting - here's an argument for fuses over breakers. Anyway, the cheap, nasty, puny, pathetic, little switch came out and I got half way through installing a lovely, big, clunky, heavy, trustworthy airplane switch. To get both new switches in the panel I have to make a few more "adjustments'....

I made the adjustments the next day. A small matt black aluminum panel now holds the new switches and the LEDs for the landing brake and gear. Everything works, and another small piece of my walnut veneer panel is gone. I added another 8 gallons of fuel. Now both tanks are topped to the brim so I can start my fuel flow calibration by setting the EM2 to zero. It will now count up the gallons it thinks I used. When I've been through a couple of tankfuls I can calibrate it by setting the actual gallons added. The EM2 will then be able to give me accurate fuel flow, HP and available fuel data. Finally, I used the EC2 controls to copy the good default data to the B controller so I have a backup if things get scrambled again. Tracy wants me to check my grounding and run shielded cables from the EC2 to the controller panel, but that's fairly big job which will have to wait until another day. It was dark by the time I got done, but at least the plane's ready for testing - again.

Saturday morning I wheeled her out and prepared for a flight, but after startup the low oil level warning light stayed on. I was indicating good pressure on both the EM2 and the gauge, and I'd checked the oil during preflight, but still...
Since I had the engine running I decided to do a taxi test anyway to see if I still had an oil leak. I took her down the runway to about 50 kts, then throttled back and taxied back to the hangar. After shutdown Paul said the engine sounded as if it was running very rough. It sounded fine to me, but the acceleration might have been a little bit off. I hadn't done a full runup where I'd have noticed lower power or rough running. Based on Paul's input I decided the plugs needed a change, and I wanted to find out what was wrong with the low oil warning anyway, so I took the cowl off and investigated. To find out if it was the sender or the wiring I cut the wire to the low oil level sensor. The light stayed on. Huh? Then I figured it out. I'd been confusing the low oil level light with the low oil pressure warning. I need to reprint the labels for the instrument panel cover. Once I knew it was the low oil pressure it was one of those "smack yourself in the forehead" times. I'd shorted out the hobbs so that it will tick over while I'm working on the plane. You see I only installed the hobbs a few hours (read 4 months) ago, and it needs to catch up with the hours I've actually done. Shorting out the hobbs had disabled the ability of the sensor to turn off the warning light when the pressure came up. Duh! I repaired the wire for the low oil level, but left the short on the hobbs for now. It's reading 12.4 currently, so I have to run it another 1.5 to catch up. Shouldn't be a problem.

With the cowl off I searched around for any signs of oil leakage. A few areas around the mount plate were just a little wet, but it looked a lot better.... until I looked at the bottom of the cowl. There was signs of fresh oil running back from the NACA. Damn. This was after just one run down the runway. I suspect the leak is somewhere near the turbo return at the front (water pump end). I started to take the fitting off, but the inspection light died. I'll pick up a new one in the morning. I'm beginning to think that the only way to find this oil leak is to take the prop off and run the engine while searching around with a good light. It's definitely not just a seep through the mount plate join. There's too much oil for that, and it only happens when the engine is running. Ah well. Tomorrow I'll dig deeper. The weather today wasn't very good for flying anyway.

Sunday is mainly "home" day, but I managed a few hours at the hangar to remove the turbo oil drain. I may have discovered the problem. The hose fitting nut could have been touching one of the front cover bolts and not tightening up all the way to make a seal. I adjusted things a little and reattached the fitting making sure it tightened up snugly. I also removed the aluminum plate where it attaches to the engine, removed the studs with the two nuts at a time trick and replaced them with bolts for easier access. Three hours work in a really awkward area, but I got it done. The RTV is curing. What's the two nuts at a time trick? You put two nuts on the stud, put a wrench on each and tighten them together very tight. Wrench on both at the same time, and the stud turns instead of the nuts..... Speaking of studs and nuts, this sets the scene nicely for the paragraph to follow.

Not a Good Week

It all on started Monday morning when I got shot in the ass. No. I mean REALLY. Not kidding. Fourteen times to be exact. At what range? Would you believe about minus 6 inches? What's even worse - I PAID to have it done. This web page is peppered with little off-topic tidbits. Here comes another one. Just skip the next paragraph if you've already read more than you wanted to know.

Apparantly, like the gear-up landing club, there's another distinguished group in which male pilots are either "paid-up" members, or WILL BE. The club involves people who earn a pretty good living donning latex gloves and inserting their middle digits into other peoples rear ends. I have to wonder - Who actually applies for these jobs? Anyway, back to the story, it seems that these guys get bored doing the "digit thing" day after day, and like to have some variety, so they invented this gun device with an sophisticated aiming system. To add to the fun, a lot of them like to do it without anesthetic. I wouldn't go to a dentist that doesn't use Novocain, I sure ain't going to a stone-age proctologist. Anyway, the long and the short of it, if you'll excuse the pun, is that it #$@%$#@ hurts, even WITH the anesthetic (don't even THINK about it without), and I was, shall we say, off my stride for a few days. The good news is that the results were negative so, guess what - he wants to try again in a few months in case he missed. Donít worry, I told him. You definitely didn't miss. I'm certain of that. Besides - how could you possibly miss at that range? I mention it mainly because I spoke to 3 Urologists before I found one that seemed to know more about the field than I did after 2 days on google, and only one who'd learned that modern medicine uses pain killers. So, if you're ever invited to join this exclusive club do some research before blindly submitting to the initiation ceremony, and make sure the guy has anaesthetic in stock, because if he doesnt use it on you, he's probably gonna need some for himself when you're done with him.

Monday afternoon, standing at the computer keyboard, I learned that Paul Conner, my Cozy check-out instructor, had everyone's nightmare - a partial engine failure at 250' on take-off in his rotary powered SQ2000 canard. He made it back to the field, but not the runway. Instead he used a parking ramp and got the thing stopped in 472'. New tires, new underwear and he's good to go. Amazing.

The following day I developed a nasty head cold, took a bunch of extra-drowsy cold formula and, before I knew it, it was Wednesday. Kevin (Clutch Cargo from the Canard Aviation Forum) dropped in for a visit, so I dragged myself down to the hangar and did some taxiing and runups to see if the oil leak was gone. It wasnít. We saw air bubbling through the seal between the engine and the mount plate, so the sump definitely had to come off and get resealed. This involves actually lifting the engine off the mount plate. On Thursday I got the lower cowl off and started on the engine mount. It was cold and dark, so I held off on the lifting. Friday I worked all day and didnít get to the hangar at all which was good because my new tool arrived via UPS. I'd read Marc Z's analysis of our brake shimmy problem and ordered a dial indicator kit from Grizzly.com for $26 to check the run-out on my brakes. Last week I thought a dial indicator was part of a phone, and run-out was what you do when the house is on fire. You never stop learning.

So, I guess it wasn't such a bad week all-in-all. My prostate ultrasound biopsy was negative, Paul Conner didn't break his airplane, and I got some work done (mostly standing at the keyboard). However, I'm happy the week is over and I wouldn't want to repeat it anytime soon. 13.9 hours and holding.

A New Twist for Sunday's

This is the new fitting which lets the hose run straight The end of the week just keeps getting better and better. I found the oil leak. Saturday was spent lifting the engine and removing the mount plate and sump. As I worked under the engine I looked up at the turbo drain line and noticed a drip of fresh oil on the lower fitting. I'd drained the oil and cleaned up from the last engine run. This oil was new. It must have come from above. I removed the turbo heat shield, detached the drain hose from the turbo and discovered the problem. This is a very short steel braided hose, and it's a very tight fit between the fittings. I even had to replace the studs on the engine with bolts to get it in place last time. The hose was bent a little as it came out of the top fitting. It was enough to twist the hose in the fitting on one side and cause a leak. I replaced the hose, used a 90 degree fitting which allowed more room to maneuver, and reinstalled the stratoflex parts being careful that the hose went all the way to the end of the insert. End of problem. I'm certain of it. The new setup is secure and tight.

I checked the oil pickup tube - after all that worring about oil pressure, it was tight and safety wired in place. No worries there. Next I cut 2 inch diameter holes in the mount plate under where the turbo and redrive returns come into the engine case. I cleaned up the old RTV on the sump and the mount plate, cleaned all the edges a razor, fine sandpaper and then with alcohol, then used ultra gray RTV to put it all back together. I lowered the engine onto the plate, bolted the sump pan back on and left the RTV to cure. Sounds easy. Took about 5 hours.

Here's another example of how the week got better. Al was at the hanger on Sunday getting his LongEz ready for a flight the next day. He'd brought with him an attractive young lady who prompty changed into a bikini and lay down to catch some rays by the hangar door. OK. This is new.

Privately Al told me she was a virgin, and he was going to initiate her. He did too, and he let me watch. A master at his trade and licensed to charge fees for his skills, Al took it slow and gentle at first, added a little firm pressure on his stick at just the right moment, and then, before she knew what was happening, Al was up and it was too late to turn back. He added full power and they both climbed into the heavens. I was impressed. Very nicely done, Al. An hour later the deed was done. Al obviously had a good time, and the young lady seemed no worse for the experience. The color was coming back to her face quite quickly. I like this new Sunday's at the Hangar idea. It's a bit like the EAA Young Eagles program, but with a Palm Beach twist.

A Slow Week

As the week progressed I only managed an hour or two at the hangar on three of the five days, but I did gradually get everything reassembled. Saturday 2/19 I finished the lower cowl reinstallation, added fluids and did some testing with the top cowl off. No more leaks. Just a little smoke from around the turbo which is probably due to my oily fingerprints. The engine ran well. There was no sign of soot on the prop. Idle is now down to 1200 rpm and the engine is smooth and consistent through the rpm range up to a static of about 4050. After taxi testing it's quite common for people to "show up" to look at the Cozy. This time I met Blake, owner of Cozy plans #0008. Blake finished the tub, then decided the plane was too small, and he was getting bigger. He decided not to finish the build, and is restoring a 182 instead, but I could see the sadness of cancelled dreams in his eyes as he looked around my finished bird. Anyone up in the CT area looking for a part finished fuselage, Blake could be someone to contact, but be gentle. I don't think he's entirely happy about letting go.

The only squark on the taxi-test was the brakes. The right brake is a little higher than the left - i.e. it engages earlier, and I still can't hold her on full power. In the light of Paul Conner's experience needing (and being able) to stop in 472 ft, I'm looking for every possible bit of stopping power from my brakes. I think the rudder stops are still limiting full brake travel just slightly. I'd like to have full rudder before the brakes engage and I need to adjust the linkages so that both brakes are equal. I began installing the upper cowl and removed the front access cover to get at the brakes, then called it a day. More tomorrow.

Sunday I finished installing the cowl and adjusted the master cylinder a little on one side, then got Al to check the travel on the rudders as I pushed on the brakes. I had full travel on both rudders, but the right pedal still felt higher, and the right rudder hit the stop before the left if I pushed equally. Al looked in the access hatch to see what was going on, and smiled. You have your right foot on the front edge of the pedal instead of the pedal bar, He said. Oops. I took the plane for a taxi test and possible flight. Apart from a couple of farts as I adjusted the mixture, the engine ran well, but I still didn't like the feel of the brakes even with my right foot now properly positioned. They were equal now, but I think I need to move the adjustable pedal forward a notch so I can reach them better. After a long wait for three spam cans in the pattern, there was a small gap, with another C172 on base. I took the runway, brought here up to about 65kts, then chopped the throttle and tried emergency braking. It stopped fairly quickly, but not as quick as I'd like. The 35 kt shimmy didn't help. I have the dial indicator to measure wheel run-out, but haven't gotten around to it yet. I taxied her back to the runway, but by this time the temps were 210/205 and there was no sign of a gap in the aluminum rain. I taxied back to the hanger via the taxiway opening her up as much as I dared to give the engine some more exercise. A Cessna was landing on the runway to my left. I was going faster than he was. Oops. Back at the hangar there was still no sign of oil on the cowl, and this time there was no smoke from hot oily finger prints either. Y'know what. Move the brake pedals forward, and I think she's ready to fly.

Pilot Squarks

Monday 2/21 I moved the rudder pedals forward one notch and tried the brakes. Much better. Conclusion - pilot legs too short. It was fairly windy and, being President's day, the pattern was full of aluminum again, but I pushed out and started up determined to get some air time.

These flight reports are, thankfully, getting shorter. What can I say. Everything went well. Temps stayed within range, the engine ran smoothly, idle was good, the brakes were better, etc. etc. etc. I stayed in the pattern and did 0.7 hrs of approaches and go-arounds. Eventually I hit a triple pilot squark. I was hot, hungry and had a slight headache. I landed (normally) and put her back in the hangar. There was a few small oil streaks on the bottom of the cowl. Maybe this is left over from some nook or cranny I didn't get to clean up. Maybe not. I'll keep an eye on it. If it hadn't been for the headache (which had been developing before I got to the hangar) I'd have taken her up for a longer flight. Oh, yes, there are a few minor items on the airplane squark list too. EM2 still keeps warning me that the voltage is within range, the brakes still shimmy at 35kts and the transponder seems to be making a regular clicking radio noise. I noticed the green light is on all the time. I wonder if it's stuck in acknowledge mode.

A couple more Squarks

In answer to Wayne Hicks, no, these aren't "squawk's", they're squarks. This is my name for a special kind of problem that comes and goes on it's own without any apparent rhyme or reason. The name comes from particle physics, where a squark is a hypothetical boson partner of a quark (you know - that guy with the ears), whose existence is theoretical, implied only by supersymmetry. I think it's these that are effecting my computer data and causing the headaches! Now, back to the story.

Today 2/22 was interesting. I forgot to mention that during the last flight I experienced that progressive weak feeling again. Richening the mixture cured the problem for a few minutes, then a couple of minutes later I'd need to go even richer to keep the engine smooth. After landing I checked the EC2 data graph and, sure enough, it was scrabbled just like last time. I mean exactly like last time. Alternate bars were zero through most of the range. I called Tracy and he suggested restoring the defaults, then cutting the program store wire just before the EC2 to eliminate any possible random noise based programming instructions. This doesnít look random to me, but I did what I was told and went flying. After a few minutes in the pattern the same symptoms returned. This time I checked the EC2 data in flight. It was scrambled in exactly the same manner. I flipped to computer B and the engine ran fine for the rest of the flight. The good news here is that the engine will continue to run quite well with total garbage in the injector map table. That's pretty impressive when you think about it. The bad news, of course, is that I keep getting total garbage in my injector map table.

I did a few patterns at altitude watching the temps and experimenting with the flashing voltage warning as requested by Tracy, then decided to bring her in for landing. There was an 8kt wind down the runway. The engine was running very, very smoothly, even at idle, so I was able to bring my approach speed back to about 80kts from my usual 90 or so. I put the landing brake down on long final, doubled checked the gear and settled back to wait for the ground to come up and meet me. I was feeling quite pleased with the smooth steady approach, thinking how nicely this bird flies, and how easy landing a Cozy really is when a gust of wind off the lake caught me by suprise at 5 ft. I pulled back instinctively to avoid touching a wingtip, touched one wheel, did a gentle bounce/zoom kinda thing to about 2 feet, then settled back down to the runway in a sort of cessna style landing holding the nose off as usual. I taxied off at the end of the runway, which is where my hangar is, without even touching the brakes.

Thinking of a question from Chrissi about how she (my plane that is) cools on the ground without the fan, I checked the temps - 210/205 - and then taxied slowly all the way back to the other end of the runway. When I got there the temps were down a little to 205/200. Ambient today was 78F, so I think that shows that she cools fine and stabalizes so long as I don't use any power. How Chrissi cools on the ground is a whole other discussion that I won't get into here....

I did another high speed taxi / braking test to get back to the hangar. At the end of this run the temps were up to 230 / 220. I shut down and climbed out, feeling quite pleased with the day and mentally drafting my email to Tracy. The engine didn't seem overly hot, but I opened the coolant access door to let the heat out.

That's when I noticed the prop. Oh sh.t, I must have clipped it on that landing.

All three tips were ragged with a flat edge to them. One had a small jagged area where a piece of the wood had departed. At first glance it looked like a $2650 write-off, but then I looked closer. The damage wasn't really that bad. There was no sign of a split on any of the blades. I measured the prop. It's 1/8 inch shorter than it used to be. A little gentle sanding with 80 grit got the rough edges cleaned up, then it didn't look so bad. I painted all the rough areas with epoxy, then added a little wet flox. I think it'll be fine when I sand the flox to shape. No one will ever know and, hey, I needed to cut the prop back a bit anyway. Clark Lydick is going to give me hell when I send the prop back for it's finishing touches. The learning experience here is that the prop is awfully close to the ground and you just can't afford to flare. I had no idea at all that I had the nose too high. Now I know the limit. Another successful test completed.

Reminders to self:
1. Don't get too slow on landings in gusty weather. i.e. Always down here
2. Don't pull up on a slow landing.
3. Add little bottles of epoxy, flox and BID to my travel kit.

I now have 14.9 eventful hours on the hobbs. This is progress - right?

Curing

Next day both the flox and the ego were fairly well cured. My first act was to check the bottoms of the winglets. No damage here, so I hadn't touched a winglet. I sanded the flox to shape and the prop looks pretty good. The prop tips are the fasted moving part on the airplane, so I decided to give it another day to cure. To help pass the time I took a look at the brakes. This meant jacking up the wheel. I was alone, and our hangar jack stands departed with the Velocity. Hmmm.

I positioned my workbench on wheels under the wing attach and got the scissor jack from my car. Next I found a suitable length 2 * 6, padded the end with a towel, lifted the end of the wing on my shoulders and used the 2 * 6 to support the wing while I got the scissor jack in position. I cranked the jack up 6 inches, and the wheel was an inch off the ground. EZ.

I removed the wheel pants and checked the runout on the disks. The highest reading I got on either side was 7 thousandths. The tires, however, range from 60 - 90 thousandths off true. The tread on the right side is a little more worn than the left, but there's plenty of landings left in these tires yet, so I'll hang onto them for a bit longer. While checking the caliper on the right side I noticed that it seemed a bit loose. Investigation showed that one of the bolts wasn't fully tight. I removed the wheel and found that some idiot - can't imagine who - had installed the caliper bolt with too thin a washer, and stripped the threads on the nut by over tightening it against the end of the thread. Also, the bolt wasn't safety wired, mainly because it didnt have a hole in it. The other bolt was correctly tightened against a thick washer and safety wired. I drilled the bolt, replaced the nut, added a thick washer and safety wired it. I think this loose caliper could have been partly responsible for my case of the shimmys, but if it persists I'll just put up with it until tire change time. While the pants were off I cleaned up the edges and sanded them down in preparation for painting.

I also took some measurements that people had requested. The distance from main wheel centerline to prop plane is 58.5", and the distance from the tip of the prop to the ground is 11 7/8" (used to be 11 3/4). Perry Mick worked this out at 11.35 degrees. It would be interesting to compare this with other Cozy's to see if I'm sitting lower, perhaps because of sagging gear. I'm pretty sure my thrust line was set exactly the same as a plans Lycoming installation, but it wouldn't hurt to check this also. One other variable that occurs to me - this was only the second time I'd flown with the fuel tanks brim full. Maybe the extra weight makes a difference to prop clearance. I'll measure the prop clearance and longeron height with level longerons and full / empty tanks, then compare the measurements with other Cozys.

Discussions with Tracy continue. He's worried about my buss voltage and the possibility of AC current coming off the alternator. The alternator checked out fine on the AutoZone machine before I installed it, but I suppose anything's possible. He's asked me to try a few more tests, then it looks as though I'll have to send the EC2 back for a replacement of the EEPROM on the A controller. If I have to send the EC2 back, maybe I'll do some painting while I wait for it's return.

The Hangar Rat

On arrival at the hangar I sanded the prop tips a little more, then used a footstool to compare the lengths as each tip went past it. One blade was about 0.1 shorter than the other two. I sanded this one a bit more until I had the difference down to about 0.05. Tracy had asked me to test the engine off and engine running voltage, both DC and AC, from various points. I hooked long wires to the EC2 ground stud, the firewall ground and the EM2 ground, then hooked the EM2 to the alternate battery. DC voltages were 12.28 at the back and 12.25 at the front. AC volts showed 1.0. I wheeled her out naked (pantless) to try out the prop and test the voltages.

The engine started easily and there seemed to be no vibration. Now DC volts were 14.23 at the back and 14.18 at the front. AC volts were 30.9 and 30.7. Really? That didn't seem right. I ran her down to the runway and did a runup. 3750 was max rpm. Strange. I did a high speed taxi. She accellerated fairly well (I'm used to REALLY well) with rpm around 3800 on the roll. She could easily have flown if I'd let her. I chopped the power and tried the brakes. The shimmy has almost completely gone away. Excellent. Now where's my power gone? I did another runup and watched the MAP. It got to 34 and stuck there all the way to full throttle. I think I know what this is. Tracy had asked me to check whether the EM2 still flashed when it was connected to the alternate battery. It did, so I called to let him know.

While I was speaking with Tracy a large rat trotted happily across the hangar floor, stopped and looked up at me. Somewhat taken aback, I said to Tracy, I said "I found a rat". "Great, says Tracy. What was it?". No, I said, I mean I really found a rat. The rat wandered off under Al's plane to chew on his nose strut so I continued the conversation with Tracy. Now he wanted me to test with the alternator disconnected and the fanbelt removed. I removed the cowl and immediately spotted the boost problem. The turbo outlet pipe to the intercooler was off. It was partly lined up, so some of the boost was pressurizing the system. Most of it was going into the cowl. I thought I'd tightened the clamp. Apparantly not enough. These silicone hose clamps like to be tightened a LOT. I reattached the hose, tightened the clamp good, then removed the alternator belt. What a pleasure it is to work on the engine now there isnt a film of oil over everything!

I pushed back to get the prop out of the hangar, then started up. I had 26v AC. I shut down. Now, with the engine stopped, I was still getting 26.2v AC on the main bus. I turned everything off except the master, then pulled fuses one by one. The 26v reading stayed. I called Tracy back. He thought this was unlikely, and had me describe the scale on the volt meter. When we established that I was on the right scale Tracy had me climb in the back and test across the battery terminals. 26.2v AC. They don't make AC batteries, do they?" I asked. If they did it would be just my luck to get one by mistake. We agreed that I need to test the voltages again with a new voltmeter. I'll pick one up on the way to the hangar in the morning. As I prepared to close up the hangar, the rat showed up again - just sitting in the middle of the hangar looking up at me. He seems pretty freindly. I think he'd have let me pet him if I wanted to. I didn't. Maybe the hangar owl will deal with him for us. Maybe he's just passing through.

Oh, by the way, someone asked me to measure the radius of the tires and the height with longerons level. Answers: Axle center to floor is 6.4". Longerons to floor is 47.2".

An uneventful flight

Saturday 2/26 the weather cleared somewhat, so I picked up a top-of-the-line multi-meter from harbor freight. While there I also pickup some diamond dremel cutting disks part #31501 ($2.50/pack on special) and some diamond sanding wheels. Where were these when I was building? I could have saved a few hundred dollars in dremel accessories. Finally, I spotted a safety wire twisting tool for $5. I've never owned one of these. I've always done it manually. At the hangar I tried out the twister. Cool. I wish I'd bought this tool 2 years ago.

I pushed the plane back to get the prop out from under the door, started up (with the alternator belt off) and tested the AC & DC voltages. 12.6 DC 0.0 AC. I reinstalled the belt, hooked up the alternator and started the engine again. 14.2 DC, 0.06 AC. I think that's ok, but I'll send the numbers to Tracy. I did notice that the alternator 'B' lead could have been tighter. Maybe I was getting voltage spikes. I'll keep an eye on the EC2 data. If it gets scrambled one more time it's going back for a new chip. The EM2 still flashes as soon as the engine starts. Maybe I'll send them both back at the same time. At least that'll save on shipping.

At Paul's suggestion I decided to see what the angle looks like when the prop is about to touch. I lifted the nose until the prop was about 1 inch from the ground, supported the prop hub at the back, then put a box under the nosewheel. The nose wheel was 14 inches off the floor. With some difficulty I climbed in and took at look at the view. Man - that's a crazy angle to be flying at, and the prop still had another inch to go. I shut the canopy and took some mental pictures of the view. I certainly don't remember having got the plane in this position, and I'm beginning to wonder again if I did the prop strike on rotation rather than landing. At least then you expect to be pointing upward. At Nat's request I measured the FS of the prop flange. 165.85, which is, I think, exactly the same as his with his 8" extension. The center of the prop to the ground, as near as I could measure without removing the spinner, is 46.25. Nat says we can operate a 70 inch prop without fear of prop strikes. Mine's a 66 and, as far as I know it's in exactly the same position as his within 1/2 inch or so. I'll send the measurements to Nat and see what he has to say.

Ah well. I lowered her back down, checked the fluids, changed the plugs and installed the upper cowl. Speaking of the cowl, I've been thinking that my upper cowl is a bit draggy and needs some work. Not on the outside - on the inside. The air from the heat exchangers is flowing into the wing root areas and can't get out. When I was blowing oil I could see the trails as air came out of the cowl where it joins the wing at the back. I can see I need to put some baffles inside to block off the wing roots and duct the air to the cowl exits. On the right side the air can't get out because the exhaust heat shield seals against the cowl. I think I need to change this, but not today. After a day of solid rain, the weather was 5000 overcast with some low scud coming in from the West. Tomorrow is forecast as another day of rain, so I wanted to get some air time if possible. I left the wheel pants in the hangar. I'll put them back on tomorrow when its raining rather than take the time to refit them now.

I removed all the ground test wires, backed the plane out and prepared to fly. Computer A data looked smooth as I taxied, but I couldn't get a radio check. I circled around to Paul who was sitting on his golf cart with his handheld. After a couple of tries I realized that the radio volume was all the way down. Oops. OK. Off to the runway. The short one was active today, but it'll do. Pre take off checks looked good, except that static was down just a tad to about 4000. There was no indication of vibration from the prop. I back taxied to get the full length and rolled. She got airborne easily and climbed, but I've seen better climb performance. I had 80 kts and wasn't getting much of a climb rate. By the time I turned downwind I was just making 900', so something's not quite right here. The engine was perfectly smooth as I headed around the pattern a few times. Not a hiccup of any sort at any rpm setting. I was tempted to open her up on the downwind, but there were other planes in the pattern so I held off and just toodled around at 100 kts for this flight. If all is well after this flight I'll get some height on the next one so I can experiment with the mixture, throttle and turbo boost. Today I was content to get airborne and do some pattern work.

After buzzzing around for a while I decided to land and check the back end. I followed a Lance on a wide left base. He cleared the runway as I turned final but, just as I called final, a Cessna took the runway calling that he'd be out of my way quickly. He'd misjudged my approach speed of about 100kts instead of the usual 60kts he's used to seeing from the Cessnas. I called, Thanks, but this is a fast approach. He rolled immediately and was just getting airborne as I came over the threshold. Being careful to keep the speed up and the nose down, I did a fairly smooth landing, held the nose up for a little while, then dropped it down to get on the brakes. The shimmy is still there. Perhaps a little better than it was, but still annoying.

The plane is now parked ready to fly when the weather clears. I have a few minor issues to keep me busy in the meantime. I'm looking forward to getting some time out of the pattern for a change. I'm wondering about the power issue. There's plenty of power to fly, and it's very consistent, but there ought to be more. The flight testing has been spread out over many months, and I'm trying to think what I'm comparing it to. It could be that I'm comparing to the power I used to get with the old turbo. The new one is designed for higher rpm than I'm using and/or getting. Another possibility is that the engine's down on power for some other reason. Mixture? Lower compression for some reason? I'm running entirely 87 octane right now knowing that I'll be forced to fillup with it at some airports I want to get a feel for how the engine handles it. Because of the low octane I'm a bit wary of giving it a lot of boost, so I'm holding back on the throttle quite a lot. The next tankful will be hi-test. Once I see how that behaves I'll try a tankful of 100LL.

Another (relatively) uneventful flight

A couple of days of low ceilings and high winds went by while I got on with other things. Wednesday 3/2 was still a bit windy, but I flew her anyway. Again the engine was consistent, which is a real pleasure, but just a bit down on power, which isn't. Take-off roll was a little longer than usual and climb rate at 80 kts was only 1000 fpm. In the pattern she behaved well, so I felt it was time to take her higher and experiment with the engine a bit more. In the early days (i.e. the first 10 hours) I would abort immediately at the first sign of a hiccup with the engine, and not take the time to figure out what was going on. This may have cost me some progress, but it made my butt feel much more comfortable. Now I've reached the point where I can experience an engine falter and take time to investigate. I had two of those on this flight. The first was the familiar "weak feeling" as the mixture drops off. I get this whenever the injection computer data table gets scrambled. (4 times now). I flipped to B and she picked right up. I checked the data table and it was back to it's alternating columns picture. The next problem took a second to figure out, and I haven't found the cause yet. RPM dropped quickly. Mixture was all the way lean. My scan took in the fuel pressure which had dropped 10 psi. I flipped on the backup pump, pressure came back and the engine settled down again. Later in the flight I reverted to the bad (left) pump with no problems. I ran on the left pump for about 30 minutes before switching back to the right side for landing. I need to check the pressure on that pump, check the filter and maybe just replace the pump anyway. Whatever's wrong with the power is totally consistent. It's maybe 20% low. On the same scale, take-off in a Cessna would be about 70% low, so I don't feel as though I'm in any danger. Whatever is costing me the power is unchanging and unaffected by throttle settings, speed, boost setting, mixture or anything else I could find.

I did 1.4 hours in 10 mile rectangular pattern over the field. At one point I recorded the numbers. 5000rpm, 5000', 33 map, 140 ias, 1680 egt, 160/180 temps, 65 oat. (no wheel pants). After landing the GPS claimed max speed at 220kt. There was a fair wind up there today. But no. Hold on a minute. That's left over from a previous flight. I zeroed the trip settings. There were a few very small oil trails on the bottom of the cowl after landing, and some soot on the prop. I'd expect the latter from the EC2 computer failure, but I'd love to know where that oil is coming from.

Now its time to take the cowl off again, change the plugs for brand new ones, test the compression and generally search for something to explain my power shortage. On this trip I did try a couple of cans of octane booster in the left tank. It didn't seem to make any difference. 16.8 on the hobbs and my bird has yet to touch ground away from home.

That afternoon I removed the cowl and the power problem, or at least part of it, was obvious. That silicone hose from the turbo to the intake pipe had come off again. I threw it away and found a nice chunky piece of thick radiator hose to replace it. I have radiator hose on all three junctions now. It seems to hold much better than the expensive blue silicone stuff. Next I removed and cleaned the fuel filters. There was practically nothing in them at all. Finally, checking around for the minor oil leak, I'm beginning to suspect the main seal behind the flywheel is weeping a bit of oil. It's a small amount. Never enough to make a difference on the dipstick, but enough to make a mess on the cowl and around the engine compartment. Tomorrow I plan to check the maximum fuel pressure on both pumps, then maybe it'll be time to fly again.

Next day I turned the fuel pressure regulator up as far as it would go and compared the pressures from each pump. Both were 55 PSI, but I suspect it would be higher if the regulator wasnt in the circuit. With the regulator set back at minimum I saw 41 PSI from each pump, and 44 PSI from both. This all seems fine, so I dont have an explanation for the fuel pressure drop. I'll double check the vents tomorrow.

I backed the plane out, started up and did a quick taxi test to warm the engine for the compression test. Power seemed to be back to normal. Excellent. Back in the hangar I recruited Mark from the hangar across the way to turn the starter as I checked the compression on each rotor. Checking compression on a rotary is difficult with the standard compression gauge because you're looking for three equal pulses rather than one. I got 100PSI, and as far as I could tell, three equal pulses, on each rotor. I think the engine is fine. My power problem was the intake hose.

As a final job for the day I remade the rudder quick disconnect linkage on the right (Char's) side. The tension was too loose in one hole, and too tight in the next. I was just in-between holes, so I made new aluminum strips with different spacing for the holes. This should get me an extra inch of rudder travel on the right side to match what I have on the left.

I installed new BUR7EQ and BUR9EQ plugs, checked the fluids and reinstalled the cowl. Before leaving for the day (it was raining) I restored the defaults to the EC2 A computer. Until I get the chip replaced I'll test that both work ok during preflight, then fly on the B computer. Tomorrow is supposed to be a rain day. Maybe I'll get the wheel pants back on for a Saturday flight.

Landing Practice

Saturday morning I propped the plane up again. This time I measured the angle of the longerons with the prop an inch off the ground. It was 11 degrees. I took some pictures and posted the various measurements to warn other new Cozy flyers of the relatively benign prop strike potential when slow heavy and inattentive. Measurements done I took her around the pattern a few times to do some practice landings. I find that I've swayed to the other side of the fence now. I'm landing a bit fast, so I just stayed in the pattern and worked on my self discipline. The only problem today was that I kept getting "Negative, Ghost rider. The pattern is full". when I tried to do anything. I waited for 6 (count 'em) spam cans to come in on final before I could get a look at the runway, and fitting into a pattern with another 6 airplanes, one of which was a Wako doing 40 kts, without causing trouble kept me busy the whole time. After 0.4 hrs it was becoming hard work, so I landed and decided to try again later in the day.

I went back down to the field at 5:30 pm and wheeled her out again. Two firsts. I didn't have anything I HAD to do to the plane before flying again, and I flew twice on the same day. Three times if you count a landing to a full stop and another take-off. In general the flying went well. The sun was low on the horizon which didn't help approaches on 027. I was almost blind in the last 50 feet and the landings were solid plants. I'd thought about a longer flight, but the sun was only getting lower (duh!) and I'm not ready for night flying yet. I am becoming more confident (and I hope competant) at flying and landing the Cozy now the engine is giving me a little space to relax and actually enjoy the experience. My big mistake of the day - (You WERE expecting one - right?) was that last take off. I landed, taxied back and got ready to take the active again. The temps were just under 200, so I did a quick runup but, so much for discipline, didn't even glance at the check list. As I climbed out the temps seemed to be getting very high. A voice on the frequency said "Cozy - I think you may have your landing brake down." Ah yes. Why didn't I think of that? I had already throttled back a bit. I brought the brake up and the temps returned to normal by the time I was turning base. Moral of the story, at least for me:

1. Never, never skip the take-off check list.
2. Adjust the throttle advance microswitch some more. 
   I'm still not getting an alarm at the throttle settings I'm using.
In general, it was a good day. Another 0.8 on the hobbs and the engine is behaving well. The plane's ready to go again, and so am I. This is starting to be fun.

Stable

This is a word I haven't got to use much during the flight testing, so I though it deserved headline status. Sunday March 6th was another nice flying day. Char came down to the airport to watch the take-off, then went over to visit her sister while I circled overhead. The controller was busy, and I felt confident enough in the engine to fly out under the class c, so I pushed the speed up to about 160kts and headed south out of the pattern at 1200 ft. I climbed to 5000' ft over Boca Raton then headed back north to circle over the airport. I hadn't given myself a list of exercises to do on this flight. I just wanted to see some stability, and that's what I got. Flying on computer B and varying between left and right tanks the engine performed flawlessly for the entire flight. Not a hiccup of any sort. Temperatures were excellent in climb and cruise. I climbed slowly up to 11,000. Working with the GPS goto function, I flew north over West Palm to overhead North County airport, then back to PBI and LNA. I gently opened her up to about 3/4 throttle and noted the following numbers: Temps 180/165 Oil Pressure 74, Fuel Pressure 40, Coolant Pressure 20, IAS 165 kts, rpm 5700, altitude 10,000, OAT 43, MAP 36, Ground Speed 220 kts. After a few minutes of this I throttled back to about half throttle and continued to enjoy the stability. One temperature reading - the analog oil temp - continues to be a problem, but I've been watching it carefuly and it seems to be following EGT. At economy cruise (the EM2 said I was burning 6.5 GPH, but it's not properly calibrated yet) my EGT runs at about 1450 - 1500, and the oil temp reads about 240. My EM2 gives me an oil temp of 175. At higher throttle settings the EGT goes up to 1650 or so, and the oil temp which has its sensor on the redrive plate too near the exhaust, says the oil is 260 while the EM2 reads maybe 185 - 190. When I throttle back, the 260 comes back to 240. OK, so I need to move that oil temp sensor. Or I guess I could keep it to see how hot things are getting at the back of the engine.

After another half hour of stability over Lantana I drove out toward Pahokee airport, 38 miles West, then back to West Palm. Still all was well. The hobbs was ticking over 19.5, so I'd done over 2 hours and decided to call it a day. Everything had been very very smooth at 11,000'. I could fly hands off with not a tremor of vibration or wind buffet. It felt as though I could have stayed there for hours and gone a thousand miles like that. One day soon I will. Today, in descent the temps were quite low at 150/130. As I passed through 5000 ft I got some turbulence buffeting that woke me up a little, then things settled down again. The controller was still busy. After a couple of tries I headed back over to Boca to descend, but as I passed through 3500 ft I got through and received clearance into the Class C. I'd much rather do this than put myself at 1200' five miles from an airfield.

Finally I descended into the pattern, did my downwind GUMPS checks and called base for the (short) active runway. There were a couple of spam cans waiting to depart as I called base. I half expected one of them to take the runway at the last minute, but was quite supprised when one actually called taking the runway and taxied over the hold point as I was at 100' on final. I made a quick, curt call. Cozy six Papa Mike is short final for zero three" and the 172 circled back out of the way just in time to save me going around. I guess they just can't see me. I'm not sure if I had my nose light on. Paul said he couldnt see it when I know it was on. I prefer to flip a switch and haven't tried messing with the main landing light levers yet. Maybe I need to do that, or paint the nose red or something.

Since I'd partially set myself up for a go-around, landing was a little fast, but acceptable, and I taxied back to the hangar quite pleased with the flight. There was some soot on the prop, but I have been keeping the mixture rich deliberately. Maybe I can back off a bit on that. The oil trail was minimal. I think it's getting better on its own. The cowl was almost cool to the touch as I pushed the plane back in.

A word about Octane

I've been getting a few comments on my decision to use 87 octane mogas. Maybe it would help if I explained my thinking on this. All the rotary experts and all the turbo experts have said that I need to be running 93 hi-test. Tracy even said the idea of 87 octane and boost gives him the willies. The problem with this is that the few airports that DO sell mogas, tend to sell 87. The easiest option would be to just follow recommendations and always use 93 or 100LL (at $3.90/gal). However, I might fly 1000 hours over the next few years not knowing that I could have done it for half the price if I'd just set some limits on the boost and mixture. I want to know if 87 is an option for me, and I don't want to blow the engine over darkest Mississippi at night the first time I get stuck having to try it. Like the stock turbo - It's one of those looking for the limits things. This time I'm hoping I don't actually FIND the limit like I did with the turbo. So far I haven't blown the engine, so it seems that I can use 87 if I keep the boost low and the mixture high. I currently use about 46 MAP on take-off, and the most I used today in flight was about 35 MAP at 10k. The airplane is entirely usable at these settings.

The next tankful will be 93 Octane and the next high speed run will involve WOT (wide open throttle) to (finally) get my definitive prop numbers. Next I'll try a tank of 100LL to see how that feels. Based on all these experiments I'll decide what my fuel of choice is, and what my operating limitations will be with each fuel option.

As I decended into the pattern today I had 19.7 on the hobbs. I thought about staying up for another few circuits just to get over the 20 hr half-way point. I didn't, so I now have 19.8 on the hobbs. Close enough. Let's close this chapter and move on. In building they say the last 10% is 90% of the work. I'm hoping that the opposite is true of flight testing. In just over a month it will be one year since my first flight date of 4/9/04. I'd REALLY like to finish the flight testing before that date passes. I have places to go. People to see.

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