[Cozy MKIV Information]
COZY NEWSLETTER #43
Table Of Contents
As always, we stopped in Minnesota to visit our kids & grandkids, to attend the christening of our newest grandson and a housewarming for our youngest son.
Monday July 26th dawned clear with one heck of a tailwind (40 kts), so we headed for Oshkosh. We set a speed record 250 miles from St. Paul to Oshkosh, ground to ground, in 1 hour flat, and we weren't even flying at full throttle! It sure is nice to get to Oshkosh before the rush starts!
By prearrangement, Chris Esselstyn had come up from Waukesha over the weekend to rope off a row on the flightline for Cozys (aptly dubbed Cozy Lane), and our pop-up camper was also waiting for us in Paul's woods, so it didn't take us long to get settled in. We picked up a car and stopped by Robbins to double check arrangements for the Cozy banquet.
The next day more Cozys started arriving. Gene & Carol Davis arrived in our 3-place, N22CZ. This was a first for us, to have 2 of our airplanes there at the same time. Actually, it was reported that our old Varieze, N2NP, was also at Oshkosh, but we weren't able to locate it. Altogether we counted 15 Cozys at Oshkosh.
The ground was rather soft from so much rain and the wheels sunk down to the wheelpants, so Gene Davis went down to the local lumber yard and had them saw up a sheet of 3/4" plywood into smaller pieces to put under the wheels. Thank you Gene! Our Cozy forum on Saturday was well attended, as was our banquet on Saturday evening at Robbins. This was the 3rd year in a row that we ran out of room. We reserved for 80, and 93 people attended. So next year we reserved for 120. The food was good and everyone seemed to have a good time. The Pershings volunteered to take over arrangements for next year, and to organize some entertainment.
We attended the IVHC banquet on Monday night, and yours truly was awarded a plaque "For Remarkable Dedication, Contnbution and Service to Homebuilders-Especially In The Area Of Expenmental Aircraft Design". Thanks guys!
Attendance was slightly off this year because of weather. One night it stormed pretty bad! Several trees were blown down in the campgrounds and 7 airplanes were overturned (no Cozys).
Tom Poberezny stopped by to look at the Cozys, and commented that they were planning to build a new wing on the museum just for prototypes of the various homebuilt designs. He said they would like very much for us to donate our 3-place prototype to the museum, and we tentatively agreed to do this next year, subject to our getting it back from Gene Davis. He is flying it until his Mark IV is completed.
We departed Oshkosh on Wednesday, and on the way back stopped off to visit again in the Twin Cities and Albuquerque. Another Oshkosh was history!
This list of Cozy builders is intended only to provide builder to builder support, for location of Cozy builders near you, and support across the country should you need assistance enroute. Someone called it a hospitality list. We have received calls from new builders who were hungry to taik with someone who had "been through it.' Cozy builders have no trouble talking about their building and flying experiences.
Nat asked us to help organize the 1994 EAA Cozy banquet. It will be held at Robbins, Saturday night of EAA at 6 PM. We have reserved a room for 120 and plan to have the meal served family style with 3 meats plus veggies, etc., including tax and tip for around $10.50. How about door prizes - any suggestions or donations?
Send us a 35mm slide of your Cozy (whatever stage it is in) by June 1,1994. Put yourself (and your family) in the picture. Add a personal comment and send it, regardless of whether you plan to attend the banquet. If your workshop has something unique (from some of the stories told at the banquet, I think several qualify!) send a slide of it.
Rex & Barb Pershing
Cedar Falls, IA 506134
A well designed canard aircraft is not supposed to be capable of stalling when operated within the approved c.g. range. Burt Rutan's designs didn't and our 3 place Cozy didn't. However, in the past few years there were 4 reported cases of main wing stall accidents in the Velocity, one of which was fatal. Those pilots who survived said that the main wing stall became "locked in", and no combination of control input or power enabled them to recover.
We don't think we can achieve a main wing stall in the Mark IV, because it is very similar to the 3-place, unless we move the c.g. far aft of the aft design limit. If we can achieve a main wing stall, we need a way to recover. So earlier this year, with the assistance of friend Tom McNeilly, we built a mechanism to install in the Mark IV which could move the c.g. about 8 inches in flight. This would allow us to move the c.g. approx. 4 inches aft of the aft limit we designed for, and if a stall occurred, move the c.g. back again to the forward limit. This mechanism consisted of a 135 lb. lead weight inside of a 6 in. diam. x 8 ft. long PVC pipe, which could be driven back and forth via an electric motor, chain, and pulleys.
This apparatus is now installed on the right side of the Mark IV, and runs almost the entire length of the fuselage. Installation required cutting large holes in the front and rear seat backs, and building a series of bulkheads along its length to support it in either the upright or inverted position. Believe me, it was really hard to cut up our airplane; I had to keep reminding myself that it was a necessary precaution for conducting these tests safely. We also installed an elevator position indicator, and angle of attack indicator, and a video camera with voice recording hooked into the radio and intercom. We also acquired a parachute (which we hope we will not have to use) on loan from Long EZ builder Harry Bawcom.
We have made arrangements for Jim Patton to do the aft c.g. testing for us. Jim is a highly qualified test pilot, having flown many different aircraft in the Navy, graduated from test pilot school, and been a test pilot for NASA for many years until recently retiring. He has had much experience in this type of testing. He will not only be able to determine and document the performance of the Mark IV for us, but he will be able to compare it with other designs he has similarly tested. More importantly, as an independent authority, his findings should have great credibility.
While waiting for Mr. Patton to arrive (his home is in Florida) we used the newly installed apparatus to determine the point of neutral stability for the Mark IV. In a well-designed airplane, if it is trimmed for hands-off level flight, and then some outside force causes the nose to either go up or down, it should automatically return to level flight, without any control input. This is called positive pitch stability.
Then, if the c.g. is moved aft, the point is eventually reached where the aircraft no longer recovers from an upset by itself.
This is called the point of neutral stability. It is important that the approved c.g. range of the aircraft be well forward of the point of neutral stability, so the aircraft always has positive stability. The point of neutral stability can be determined from data on the relationship between speed and elevator position at at least 3 different c.g's. Being able to move the c.g. in flight made it much easier to obtain this data. It then must be plotted as shown in Figure 1.
One then measures the slope (the change of elevator position vs. the change in speed) of each of the c.g. curves for several different speeds, and plot these as shown in Fig. 2.
These plots should all intercept the abscissa (horizontal axis) at the c.g. for neutral stability. For the Mark IV this turns out to be a c.g. of 103.9. This is good news because it is well aft of the c.g. range that we designed for.
We are planning to display the Mark IV, with its variable c.g. mechanism, at the Copper State Fly-in October 1-3, for anyone who is interested to see.
Cozy 442 took to the air on 6/27/93, at 6:25 PM. The flight was utterly uneventful! The Performance Props 3-blade was the star performer, giving a smoothness and power that has to be experienced. Starting from the beginning, the airplane weighed in at 981 lbs. with oil, is equipped with an 0-320, light weight starter and alternator, a light VFR panel with no vacuum system, but comm radio and transponder, Apollo GPS and hand held backup. The ignition system consists of a non-impulse Slick, and one of Jeff Roses' ignition systems, with all the bottom plugs being on the electronic unit. These are the Bosch plugs that Jeff sells. This thing works, the drop when the mag is off line is unnoticeable at idle. The induction system is one of the many things I stole from Vance Atkinson, a Performance Airflow fuel injection system. The engine starts and idles flawlessly and turns 2500 static, 2850 in cruise. All temps were normal with standard cooling system, and Vances' oil cooler installation with the separate scoop. This is a freshly overhauled engine, which I ran on the ground for an hour in five min. increments till the temps stabilized for more than 10 min. at ambient temp of 85F. During this time I shut the engine down any time CHTs got to 350F. In between runs the engme cooled enough to touch. This with thanks to a very informative letter from another builder, published in this newsletter. Do it, it works. The highest CHT I saw was about 425 during first flight, although I did a good deal of climbing and descending while dividing attention between instruments and horizon. Nat, I want to say m closing, that all of the products I mentioned here were reasonably priced, backed up with excellent service and technical support, and meet or exceed the makers performance claims. Special thanks to Ken Miller for his expertise throughout, and to Dewey Davis for a very generous and very skillful checkride in his lovely Cozy. To all you builders, yes, it is worth the long journey, to feel those wheels break free, and see the sky come down to meet you!
Lastly, thank you, Nat, for having the skills and imagination to make this such a wonderful airplane!
COME ON GUYS! LET'S HAVE THOSE FIRST FLIGHT REPORTS!
I'll start at the beginning. When we got married, Chris started building the Cozy. Naivete of course is part of the "I do" vows because you don't really know what that means until you live it out. So it is with the Cozy. In marriage having learned alot about both, I can now confidently & joyously say that both are worth the effort. During the building stage my effort, whilst Chris built, was encouragement. Now I (and most of my worldly belongings) & Chris as chauffeur fly around.
We take approx. 3 major trips per year. Being out-doorsy types, most of our recreational interests are in the western states. We live in Waukesha WI. In the winter we take a quick skiing trip to Taos NM, where our friends live. We UPS our skis ahead of time. By leaving @ 4 AM, we are able to ski for a half day in the afternoon at Taos Mountain. That's convenience!
On the way home, we ski m the morning and fly into the night. It's approximately 7 hours flight time with prevailing westerlies. In the fall, we fly to Teton National Park, in Jackson Hole WY. We carry a week of back packing equipment with us (sleeping bags, tent, stove, packs, food, and clothes). Jackson airport is about 5 miles from the entrance to the park. We fly in, lay out all our gear on the ramp, pack our back packs, tie down the bird, & hitchhike to the park. I think we might look a little like flying gypsies!
This spring, we went to Lakeland FL for Sun & Fun. We enjoyed the weather, and less regimented style of the fly-in than Oshkosh. Besides the Cozys, there was a balloon race, a B-1 bomber, and teriffic sea of planes. Revelie bugled every morning at 6:30 AM. We camped at the fly-in a few days, then rented a car & went scuba diving into the fresh water springs in North Central Florida. We even swam with a Manatee. After driving back to the plane, we flew to Boca Raton to visit friends, then on to Key West. Key West has a good airport and is a fun place to fly to.
When we flew from Waukesha to Lakeland, we had a 50 Kt. tailwind. Flying at 11,500 ft. we cruised at 200-220 knots and arrived in 5 hours flight time. This outstanding performance was achieved at close to gross weight!
During the good old summertime we fly to Oshkosh. That's a snap for us. We live 90 road miles away, and 30 minutes by air (unless you're in the pattern for an hour).
Because our vacations are centered around kayaking, mountain climbing or scuba diving, we haul a lot of gear. As some of you have already witnessed, I have perfected the technique of packing the aircraft. Our plane is utilized like a work-horse. Still it maintains fast, efficient and cost-effective transportation with it's elegant and graceful design. It is sturdy, safe, and a joy to fly in. Flying at 18,000 ft. over the motmtains is not uncommon for us. Besides the plane itself, the Cozy people are a wonderful group to be with. They're friendly, and always willing to give a helpful hand, and share advice. It's an honor to be part of such a fun, organized and outstanding group.
I have become very spoiled by "Iapetus". The only plane that I can imagine that might be better than a Cozy is a cargo carrier that burns 10 gal/hr. Then I could really bring all my gear and get to those remote places. I'm not going to hold my breath.
If you have already built part of your airplane with Safe T Poxy, RAE, of PTM&W, there is no need to worry because all of these epoxies have acceptable properties and adhere to each other if the surface has been properly prepared.
We will be trying the new epoxy first hand very shortly, and will report in the next newsletter.
Dr. Curtis Smith
1846 Sextant Dr.
Worden, IL 62097
Please find enclosed a check for plans and info. pack. I am a Long-EZ builder, and I have been following the construction of a Mark IV by my neighbor, Don Hansen.
Thank you for your support of "amateur aviation".
Marvin Bowers III
July 23, 1993
Dear Nat & Shirley,
Enclosed is a check for the newsletter. Enjoying the Cozy we purchased. Formerly N566MG but now N34PC. Will be at Oshkosh this year again.
Finally got my wife to go on an 800 mile cross country (her first ride in the Cozy). Now when ever the prop is turning, she's standing there with a suitcase. She won't even consider getting back into the Cessna 310.
Feb. 12, 1993
I hope this letter finds you and your wife m good health. As I write, another of our Mid-Michigan snow storms is passing through. Got any extra room out there at Falcon Field? My Cozy Mark IV is progressing nicely. We just pulled the fuselage sides out of their jigs last night and the next week or so should see us fitting the fuselage sides to the bulkheads. It seems that all the builders have nothing but praise for your plans and we certainly agree.
My main reason for writing you is to discuss the epoxy systems we use. I started with the RAE system. I didn't even complete the bulkheads before a pretty good rash developed on my arms. I stayed away for a week and came back and did a little 20 minute layup and it was like I rolled in it. Boy, did I hurt! I had to switch to Safe T Poxy or I was finished.
Safe T Poxy seems to be just a little more viscous than the RAE system. To keep the epoxy good and fluid, I built a warming box. A 25 watt bulb keeps it at 80F. I even started keeping my flox and micro in there as well. Now, any mix I make is good and warm. Using this 80 deg. epoxy in a 70 deg. shop really does the trick. If I've had the epoxy out for an extended period and it thickens up a little, a couple passes with the hair dryer fixes it right up. My allergic reactions have all healed and there is no swelling or irritation at all. While it's lower in toxicity, a good barrier creme is still required.
I wanted to let you know about my experiences with the Safe T Poxy system because I get the impression from the newsletter that there's a number of people out there struggling with allergic reactions when they really don't have to.
Jan. 6, 1993
Thanks again for helping me out on the phone the other day. I had called concerning extra space in my landing gear attachment. You recall that we discovered that I had installed the bushings so that the flanges were on the outside of the bulkheads instead of the inside. You suggested heat to help get them out since they were already floxed in place. That however made me a little nervous and I knew I did not want to pound them out, so after thinking for a little while, I pressed them out using a 3/8" bolt, a nut ground down to 5/8" and a bunch of washers. It worked really well removing the parts without any damage. A couple of them were really in there! After reinserting the bushings in correctly, the landing gear fit very well. As a matter of fact, the whole strut took many hours, but came out very, very well. I amazed at how it all fits together when you follow the plans.
Thanks for sending me a copy of Newsletter #27. There is a wealth of information in the old newsletters. I originally received them because I had purchased the 3-place plans. Some Mark IV builders might want to have a complete set, from #4 on. I finally got a ride in a Cozy! It was everything and more that I thought it would be. The Cozy builder who let me fly in his plane gave me much more than a once around the pattern flight. I can't thank him enough. It was an experience I will remember for a lifetime. I can't wait to finish mine. again,
Dr. Jim White
Just a quick note to say thanks for the hospitality at Oshkosh. I enjoyed the visit with you and Shirley and your friends the Davises and Vargases.
I've been flying a lot this month so the only thing accomplished on the MK IV has been the left wing sheer web layup and the bottom spar cap. Hope to skin the wing this week. The right wing, canard, elevators, fuselage, and center section spar box are done, and all foam is cut. So far $7,474 and 357 hours invested. I've had to do some layups in 95F weather if I want to get anything done this summer. The layups seem OK, the glass wets out well, but cure time is very quick. The Safe T Poxy II cured to knife trim in less than 5 hours. The downside seems to be a short squeegee time.
Nat, you are providing we builders with much good info and detail. I read the newsletters on layovers, and sometimes carry the plans also, and am really impressed with the material you present. I wish I could write as well as you do (I guess a college education would help). The article on propellor installation, last newsletter, is standout excellent.
I am searching for an 0-36O A4M. It's the latest version, I think, with all late mods, a solid crank, no counter weights, and Slick mags. I am finding out they go fast. I had a line on one and it was gone by the time I called. But I will keep looking and I'm sure one will turn up.
I am glad we met and talked. Hope to see you again. Say hello to Shirley. My wife Margie wishes she had not missed your hospitality.
Enclosed are some photos of what may be the only 3-place Cozy to sport a Mark IV nose. I had to build and shape the rest of the nose, aft of the lovely Feather Lite nose cone, to fit the prefab part. I am fairly pleased with the results, but I will be doing a bit of reshaping to get rid of the micro-joints.
The main gear rework you recommended worked like a charm, and just beats heck out of any of the radical solutions my boyfriend and I had come up with. You may remember I told you that the main gear mounts on the fuselage had been incorrectly placed by the original builder, resulting in a half inch height difference between the main axles. I had begun to wonder whether, in skinning the outside of the fuselage, I had somehow "twisted" the airframe, thereby moving the mounts out of
OKAY, this is the OTHER side of the cutout - what's in this paragraph?????
Thanks again for being there when i needed advice.
I'd like to ask you, and other builders, for good sources of information on engines - what to look for, what to avoid, what models are best, what all those letters mean, where the deals are, etc., People have told me, "It's a whorehouse out there." I can't afford to get rolled, so any advice is welcome. Please print my address in the newsletter for interested parties to respond.
Liese C. Aufill
2555 Federal Ave
Los Angeles CA
Dear Nat & Shirley,
Please find enclosed a check for the newsletter. I always look forward to the newsletter, especially the news of completed Cozys.
We enjoyed Oshkosh much more this year from our new perspective as builders rather than purely spectators. My only regret was that we had to leave Sunday in order to make it to work Monday morning.
I want to thank you once more for the invitation to sit in your Mark IV. Recognizing the fact that you can't possibly allow everyone the privilege, we were very appreciative of your invitation.
Since Oshkosh we have been building the right wing. My wife and co-builder (one in the same) was my right hand and the result was a wing we are very proud of. The wing layups progressed with a minimum of difficulty. I am expecially proud of how easily the glass was laid down, wrinkles removed and finished out. This was in sharp contrast from the first layups where great battles were fought and won!
In closing I want to commend everyone who was able to attend the Cozy builder's dinner at Robbins. We enjoyed meeting everyone and look forward to networking with them. The atmosphere at the dinner was fabulous.
Enclosed is a check for your info pack. From the review in U.S. Aviator and from electronic correspondence with one of your happy customers, I should stop saving for a Lancair and immediately get to work building one of your Mark IVs.