Date: Sun, 07 Jun 1998 21:00:35 -0400 From: David Domeier Subject: Re: COZY: Antennas and taxi time... Nat, Re "I always install com antennas in each winglet, but never had to use more than one, and never had a failure. My radio reception and transmissions are better than most factory builts (I am told repeatedly)." I agree. I've got 2 VHF's and they are both working fine with an antenna in each winglet. Performed 3 high speed taxi tests today....all went well. Nose comes up at 55 knots very easily and in one test I think the mains lifted off for a second....I heard a little tire squeek when they settled in. The airplane feels like it is ready to fly. No leaks so far. Highest CHT was 342=B0C on #3 so cooling is working OK. Fuel pressure transducer has failed so that will have to be fixed before first flight....it was OK but now reads zero all the time. Take off RMP is 2370...is that in the ball park? I have the same engine and prop the proto-type has. The airplane accelerates very quickly compared to the 0-235 powered LEZ. So far so good... dd From: cdenk@ix.netcom.com Date: Mon, 8 Jun 1998 16:21:55 -0500 (CDT) Subject: Re: COZY: Antennas and taxi time... 2350 RPM isn't bad, maybe slightly high. depends some on air temp and altitude. Aim up and down wind, average and report that. Date: Sun, 21 Jun 1998 20:39:49 -0700 Subject: Re: COZY: N10CZ First Flight Update From: alwick@juno.com (ok How) David, you'll never know how much I enjoy reading your update. Thanks for sharing. Couple comments: That fuel dripping was part of the cause for one of our fellow pilots catching plane on fire. He had fire ext and only had to redo the engine cover on his cozy. I can't remember the details. I believe the fuel pooled at bottom cowl under certain conditions. I forget what caused it to light off. Nat may have some insight on this. You checking for grey streaks coming from ailerons? Flutter? Just trying to help. Thanks again. I'll be dreaming of flying again tonight. -al wick 79% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components, now sand, spend, sand. On Sun, 21 Jun 1998 21:18:51 -0400 David Domeier writes: >To all Cozy forumites - N10CZ first flight (second flight) update. > > After the first flight on June 18, just ahead of a batch of very >nasty >MKIV #155 > > _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] Date: Mon, 22 Jun 1998 07:00:53 -0400 From: David Domeier Subject: Re: COZY: N10CZ First Flight Update Correction on my last post: re "I think the FAA person requesting this item is screwed up because his reference, FAR 25.101 does not apply to Experimental airplanes." The FAR regarding repairman certificate is 65.101 and 65.104, not 25.101.... dd Date: Mon, 22 Jun 1998 07:43:02 -0400 From: David Domeier Subject: Re: COZY: N10CZ First Flight Update Another correction to my post last night - man, was I tired... re " This afternoon I decided to fix the roll trim problem by adding 2 thin washers to the top right wing attach bolts between the center section spar and wing. That took about 3 hours...what a bear it is to remove those bolts and get them back in." I added the washers to the LEFT wing so as to increase it's angle of incidence slighty. The right aileron trim indicated that the right side was producing more lift than the left so I figured I had to increase lift on the left or decrease lift on the right, or both. I probably should have added one washer to the top bolts, left side, and one washer bottom bolt, right side, but the thought of removing BOTH wings yesterday was beyond what I wanted to do about it. In any event, it cured the problem. I now have to deal with a slight miss match of left wing to strake, but I've got the rest of my life to fix than problem. I've got some other cosmetic anomalies that only EAA guys notice and will deal with them also when time permits....the critical measurements of this airplane are right on, but the finish job could be better, all because I really HATE sanding, filling, sanding, filling, priming, and painting.....I mean I'd rather fly a 1000 times over spending the rest of my life finishing an airplane. I'm sure people who go to hell in the next life spend much time doing such work.... dd (slightly more awake this morning) Date: Sun, 21 Jun 1998 21:18:51 -0400 From: David Domeier Subject: COZY: N10CZ First Flight Update To all Cozy forumites - N10CZ first flight (second flight) update. After the first flight on June 18, just ahead of a batch of very nasty thunderstorms and a 3 day work schedule, I=92ve had to reluctantly stand down until today, June 21. I awakened this morning at 5:30am after a very noisy night of lightening, thunder, and rain to find the sky clear. It was also very calm...a perfect time for the second flight. I told my dreary eyed wife I=92d be back for breakfast by 8:30. I got to the airport at about 6 with no one around but one FAA guy working the tower. I pushed the airplane out of the hanger, did the walk around and climbed aboard. (I pulled the cowlings and inspected the engine compartment during rainy weather yesterday.) I=92ve learned it is not necessary to prime this engine (0-360-A4M) with electronic ignition...simply push the mixture to full rich, open the throttle a bit, and hit the starter. It roars to life almost instantly. The Ellison unit dribbles a bit of fuel out the intake when I turn on the electric pump before start. It does not do it if I start with the electric pump off and shut down the engine with the pump off. I know most of you guys have a few flights in perfectly calm air. It was such a morning until about 8:30 today. The second take off was a delight...just a little back pressure at 60 knots, the nose came up slowly and I was flying. The game plan was the same as the first flight...right climbing turn to 2500 feet, keep the runway near in case the engine found a reason not to run. But it didn=92t. It purred very nicely. My major concern has been dirt in the fuel system. I flushed it after some 2 hours of taxi time and found almost not dirt at all. I then pulled the gasolator filter, the in line filter, and the screen at the Ellison unit. No dirt at all! I was a little surprised and skeptical...maybe I did get all the saw dust sucked out after opening the tanks to install the fuel caps. On this flight I noticed I needed quite a bit of right aileron trim to keep the airplane level. But it was very controllable. After about 20 minutes of turns and feeling out the controls, I decided maybe I should go back in for some fuel. On the first flight I carried about 15 gallons since I did not want to cause too great a fire if things went really bad. This time I added 20 gallons to the 5 or 6 remaining and decided to take it up to 4500 feet, once again over the airport. I let the airplane accelerate at full throttle for several minutes. It indicated 150 KIAS and trimmed out very nicely in pitch. It would have gone faster but I didn=92t want to push the envelope to quickly. Aileron trim was still about half way full right. On the third flight I decided to fly rather than drive to meet my EAA Tech Advisor to have him sign a letter attesting to my qualification for the Repairman Certificate. I think the FAA person requesting this item is screwed up because his reference, FAR 25.101 does not apply to Experimental airplanes. We should be using 25.104 and I will raise that issue with them tomorrow, but I also have letter in my back pocket if needed. That flight was my first venture away from home plate and went well although the skinny runway made me a bit nervous. It looked about 12 feet wide. Some people were have a BarBQ at that airport and of course came to looked at my creation. This afternoon I decided to fix the roll trim problem by adding 2 thin washers to the top right wing attach bolts between the center section spar and wing. That took about 3 hours...what a bear it is to remove those bolts and get them back in. I took off for the 4th time at about 4:30 to see if the I needed the aileron trim anymore...I do not. This time I flew west about 10 miles and climbed up through a scattered deck to 4500 feet. I did a few steep turns and on descent let it wind up to 160 KIAS. No pieces departed the airplane so my envelope is now successfully opened to 160 KIAS. On the slow end I=92ve flow it at 70 KIAS on final. The full aft stick stuff will come next week out west at about 8000 feet. What am I most pleased about this airplane? It flies like a mini jet fighter. On the last landing the tower guy asked me to make a short approach from down wind =91cause a Cessna was 2 miles out on final. That was a pleasure. Opposite the numbers at about 700 feet, gear down, pop the board, and a descending 180 turn to the runway...long finals behind Cessnas in this airplane are a real bore. Keep building guys, you=92ll love to fly this airplane. dd MKIV #155 From: "Nat Puffer" Subject: Re: COZY: N10CZ First Flight Update Date: Mon, 22 Jun 1998 09:38:06 -0500 Dear David, If you have to add washers to either wing attach to compensate for one wing providing more lift that the other, the question is whether to increase the angle of incidence of the heavy wing, or to reduce the angle of incidence of the light wing. Either will level the wings, but then the question is, how is the resulting incidence compared with the canard incidence. The only way to determine that would be to level the airplane and then check the incidence of both the canard and the main wings. If the main wings have too much incidence in relationship to the canard, that will reduce the stall margin. In our flight tests, after adding lower winglets and shortening the canard span, we checked for stall resistance in level flight at idle power, slowly coming back on the stick until we got full aft stick. With everything correct (lower winglets and shortened canard span), we still didn't get a stall at a fuselage station 1.3 inches behind the aft c.g. This told us that we had an extra margin of safety to cover builder differences. Before shortening the canard span and adding lower winglets, we were able to get a main wing stall, but we never had to move the c.g. forward to recover, because we watched the airspeed indicator, and when the main wing stalled, the airspeed suddenly started dropping from 50 knots toward zero. By applying full forward stick while the airplane still had forward motion and the elevator was still effective, the airplane recovered nicely. We did this a number of times (at least 12) both Jim Patton and I, and always were able to recover without having to move the 135 lb. weight from the firewall to the nose. A word of caution, we did not check any violent maneuvers, or any full power stalls, or stalling at full power and chopping power, or hammer head stalls, because this airplane is not approved for those types of maneuvers. It is classified in the normal category. Not utility, not aerobatic. Incidently, for other builders reading this, the shortening of the canard span applies only to the first edition plans. The span was corrected on the second edition plans. The lower winglets are shown on both editions. When we built our plans model, we left them off to test to see if they were required, and we learned that they are. We hope that no builder would make any changes which might affect the stall characteristics, and then go up and do stall tests at aft c.g. or unapproved violent maneuvers without having installed a traveling weight mechanism that is capablable of moving the c.g. at least 6 inches forward. Tossing a sack of lead shot forward, as one builder thought, won't hack it! Also, you should double check your weight and balance and c.g. calculations, and if there is any question about whether you have done it correctly, seek some expert help. If anyone has any questions on this matter, please contact us. Regards, Nat Date: Mon, 22 Jun 1998 11:59:59 -0400 From: David Domeier Subject: Re: COZY: N10CZ First Flight Update More on first flight - Just a few kudos on stuff available for the Cozy ... The Steve Wright electrice nose lift adds some weight but it is up front where we need it. The unit works very well but we must be prepared to deal with loss of electric power, i.e., have a ratchet device on board at all times for manual extension. And make sure it is 6 point unit, not 12. The Wayne Lanze electric board extender is very handy, but also one must have some sort of indicating system of where it is. I cut a 2 inch hole in the back seat rest too see it visually and have a yellow light also. I've decided not to extend the unit until I am committed to land. The engine CHT's go up very soon after extending the board and I wouldn't want to miss the approach and not be able to retract it. Wayne also supplied the electric panel. Very, very neat unit. Makes hooking up the electric system EZ. I like the low voltage warning light feature of the B & C linear regulator. I feel it is a must when operating with electronic ignition. The Jeff Rose electronic ignition is operating very well so far. The engine starts almost instantly and runs very smooth. The pros and cons on electronic ignition need be considered though before committing to it. I've read Cessna has dropped it from the production line because it does not deliver much fuel burn advantage and it does cause higher CHT because of earlier ignition. It was their conclusion the added cost was not justified. dd Date: Tue, 23 Jun 1998 15:59:47 -0400 From: David Domeier Subject: COZY: Third day of flight testing N10CZ Third day of flight testing - N10CZ Yesterday was stand down day. I pulled the cowlings again to check for leaks and anything else that might be loose. Everything looked OK. I also layed up a panel to cover the battery section aft of the rear seats and worked on a glare shield. Today I had three objectives: 1. Climb to 8500 feet and do a flat out run to check for max prop RMP and IAS at 75% power. 2. Perform aft stick maneuver at minimum speed. 3. Expand the envelope to 190 KIAs on the way down. I adjusted the CG aft of the 100.5 limit I used for the first flights to the rear limit of 102.0. I had 43 pounds of ballast and reducing it to 26 pounds moved the CG to 101.96 - close enough for government work. Flying at the aft limit is actually more pleasing than forward of 100.5. The airplane rotated smoother and seemed to perform just a bit better. The climb was uneventful although I noticed a cloud deck moving in so I did not have much time. The 75% run produced 155 KIAS with 2680-90 RPM. Pretty much in the ball park with the prototype (I think). True airspeed works out to 182 knots which equals about 210 MPH. (assuming the IAS is accurate) I enter the aft stick maneuver very gradually. Heard too many stories about flat spins so I was bit apprehensive. But all for naught - at 55 knots the nose dropped slightly and the airplane began to descend. I had full aileron control. I don=92t think the airplane was anywhere near departing flight. Enough of that. I didn=92t spend a lot of time trying to get it to depart. I pushed the nose over and let the airspeed built up. With the throttle just above idle the speed built up very quickly. From 160 on up I did it gently waiting for the dreaded signs of flutter. But again, all for naught. At 185 KIAS I eased the nose up and headed back to SUS. Total flight time about 30 minutes. After landing I discovered one prop blade to be damaged. It had a ding about 4 inches from the tip that was about an inch long and about 3/8=94 deep. Good =91ol dummy decided to use removable 2600 Camlocks instead of screws on the bottom cowling and guess what - one of the Camlocks removed itself inflight. I had a sinking feeling I would have to return the prop to Performance for repair and the flight test program would be delayed for 6 weeks. I called Clark Lydick and told him what happened. He said it happens all the time, and yes, I could repair it myself! So I mixed up some 2426 with flox and should be back in business tomorrow. I am also removing the Camlock receptacles and reinstalling nut plates. dd MKIV #155 From: cdenk@ix.netcom.com Date: Tue, 23 Jun 1998 17:46:40 -0500 (CDT) Subject: COZY: Camlocs Domeier writes I hsven't lost one in 600 hours, probably not accustomed to when they are properly seated and proper length. The correct length is the head is flush to slightly recessed with the panels snug. I hope you don't go back to screws, they will vibrate out and into the prop!, The nut plates wear out to help this. I picked something off the runway the day before the FAA came, split the prop lengthwise 4 inches. The moral: Always have a spare prop ready to ship, with someone instructed how to. Date: Wed, 24 Jun 1998 09:26:15 -0700 From: michael amick Subject: Re: COZY: Third day of flight testing N10CZ David Domeier wrote: >=20 > After landing I discovered one prop blade to be damaged. It had a din= g about 4 inches from the tip that was about an inch long and about 3/8=94= deep. =20 > ...He said it happens all the time, and yes, I could repair it myself! = So > I mixed up some 2426 with flox and should be back in business tomorrow. >=20 > dd > MKIV #155 Might be good idea to rebalance the prop since the damage was so close to the tips. Michael Amick MKIV plans#317 Date: Wed, 24 Jun 1998 17:27:35 -0400 From: David Domeier Subject: COZY: Flt test day 4 - elevator position Flight Test Day 4 - Elevator Position Nat, Today was boring holes day - I=92ve got to log some time to get this thing out of phase one. In the process, I decided to see what the elevator was doing at various speeds. First of all I measured elevator angle from side to side on the ground to see if they were out of rig. The left side bottom at the outboard edge next to the canard end faring read 9=B0 up. At the same spot on the right side without moving the elevator, it was 10=B0 up. So the elevator= s are within 1=B0, at least at that point. I rigged up an angle measuring device made of aluminum, covered it with masking tape so I draw some lines on it and taped it to the left canard inboard tip faring next to the elevator. I then marked the device in degrees at 5 up, zero, 5 and 10 down. I know this is not very scientific, but I figured it would be something to look at while I lolli-gagging along within my 25 mile radius leash area. It was hot in St. Louis today - about 95=B0F. So the ride was a little bumpy, but here is what I saw. At 70 KIAS the elevator was at 3=B0 down. At 90 KIAS it was 0=B0 At 110 KIAS it was 2=B0 up. and at 130 KIAS it was 3=B0 up. Are these numbers in the ball park? I think too, we must consider that I was flying with the CG at the aft limit of 102. Obviously, if the airplane were loaded to the forward limit of 97.5, much more elevator down would indicated. I am pleased with engine cooling. The Vision Micro system records maximums and minimums for each flight. Max CHT was 386, oil temp 193, oil pressure 76, rpm 2380, manifold pressure 29.5, fuel flow 13.5, amps 28, and volts 14.2. This system is the cat=92s meow!! It also keeps track of fuel burn based on f and appears to be very accurate. It will tell you how much fuel remains in gallons and time. At 100 KIAS I was burning 4.3 gph! (1700 rpm) What a way to sight see Missouri. Thanks for a great airplane. dd From: "Nat Puffer" Subject: Re: COZY: Flt test day 4 - elevator position Date: Thu, 25 Jun 1998 08:03:45 -0500 Dear David, I plotted your points, elevator position vs speed at a c.g. of 102. They are definitely in the right ball park, but the shape of the curve doesn't look the same as the curves I plotted, so I am wondering how accurately y= ou were able to measure. I had an expanded protractor attached to the tip of the canard, and a needle extended from the tip of the elevator so I could read within plus or minus one degree. If your readings are not that accurate, then about all we can say is what you already know, that your airplane is stable in pitch and has at least the same stall resistance as mine. Regards, Nat Date: Mon, 29 Jun 1998 08:11:24 -0400 From: David Domeier Subject: Re: COZY: Flt test day 4 - elevator position Nat, re " I had an expanded protractor attached to the tip of the canard, and a needle extended from the tip of the elevator so I could read within plus or minus one degree. If your readings are not that accurate, then about all we can say is what you already know, that your airplane is stable in pitch and has at least the same stall resistance as mine." My measuring device was not as well done as yours, so there definitely is room for error. And it was quite bumpy that day. But I think the proof of the pudding is how the airplane responded to a full aft stick maneuver at minimum speed. I'm satisfied it is safe and I guess that is what flight testing is all about, even though it is being performed by a non test pilot. I now have just under 10 hours on the machine and am working on finding the best approach and flare speed. I've made a few too slow and few too fast. It seems 75 knots and a "flare, fly it on" method is producing the best results. In one case I tried to hold the nose off by increasing back pressure as soon as touch down occurred and found myself nose high airborne again, which was not good. It was in the high 90's again yesterday and I continue to find the cooling system working well. Max oil temp was 181° C which is when the poppet valve opens. I did seal the wing-center section joint and the edges of the oil cooler after one flight when the CHT hit 400°. That made a difference. I have also found that aggressive leaning at low altitude will cause the CHT to go up almost a fast as EGT. I pushed the mixture forward and could see the CHT drop. That may be a result of the Jeff Rose electronic ignition firing so far in advance of the mag...fuel does help cool the cylinders on very hot days. dd From: cdenk@ix.netcom.com Date: Mon, 29 Jun 1998 16:04:09 -0500 (CDT) Subject: COZY: Flare speed If you are flaring with one person in the front seat at 75 mph (knots)(which) then probably with maximum front seat weight it will be 90 (units). Get 5 50 pound sand bags. Gradually add a bag and explore flight caracteristics. Also add atleast 5 knots for rain and 10 or more for 1/8" ice. Date: Mon, 29 Jun 1998 18:35:46 -0400 From: David Domeier Subject: COZY: Re: Flare speed Carl, re "If you are flaring with one person in the front seat at 75 mph (knots)(which) then probably with maximum front seat weight it will be 90 (units). Get 5 50 pound sand bags. Gradually add a bag and explore flight caracteristics. Also add atleast 5 knots for rain and 10 or more for 1/8" ice." Seems to me, if an airplane is trimmed properly, at a stable approach speed and in a normal visual slot, it ought to flare about same no matter what the CG is, so long as it is not out of CG limits. I'm just trying to establish what that speed is. 75 KIAS seems very comfortable, but that's at about 1500 lbs. A heavier weight might need 80 KIAS, as would a gusty cross wind. Some of you guys might have noticed that I've been referring to Lycoming temps as degrees C. As Nat points out, Lycoming temps are in F and I'm sure my indicating system is degrees F. Whatever numbers I've been posting, they are in F. dd From: cdenk@ix.netcom.com Date: Mon, 29 Jun 1998 20:46:35 -0500 (CDT) Subject: COZY: Re: Flare speed First remember my COSY is a little nose heavy and the canard is 6" longer overall. My front seat is 400 lbs, and I use 1900 lbs gross as a limit. I use 95 knots as over the fence with 2 people in the front seat. With only myself in the front seat, I might be as slow as 75 knots. With full load and front seat loaded on takeoff, I will either raise the nose wheel slightly and let it fly off, or run along flat, elevators in trail to slightly down to 85 knots and haul it up abruptly and keep climbing. There are 2 CAUTIONS: 1: On landing, there must be enough airfow over the canard to flare! If you are too slow, it will be a carrier landing, squating the gear major. You will find this by testing, every aircraft is different. My Ideal approach is rather steep, with the right amount of airspeed, judging the weight and balance to flare nicely and settle nose high onto the runway. I frequently deploy both rudders or slip to lose altitude close in. My normal ground run at 780' elevation with fairly hard braking is 2000' 2: On departure, carrying the nose too high or lifting the nose to high too soon, will result in lifting off, settling back to the runway several times before there is enough airspeed to sustain flight. This is the backside of the power curve, where my IO-320 is able to power out of, but it takes lots of runway. For this reason, I don't take chances with getting the nose high on takeoff, but run along in a minimum drag configiration/attitude to 85 knots, and the a F-16 type takeoff, nose up, your flying with a good rate of climb.