Dec 31, 2017     Why Cozy & Progress - (20 hours)       Category: C01 Introduction

PK - My decision process took place in 2016-18. Things stabilized enough that I again had a long term residence with garage space. I still have the PA-12, but I like having a project. My track record was buying and restoring a BD-4, buying and restoring a PA-12, partnering in a RV-6a and EAA BiPlane, and volunteering on the EAA's replica of a Bleriot (steam bending ash!). In each of those I was a shadow and assistant to projects led by experienced builders in Hartford's EAA Chapter #166. I may have confidence greater than my ability, but that risk is balanced by openness to critical review, a willingness to redo bad work and a lot of patience. So long as I 1) listen to experts and 2) recognize when I've made a practice piece, I can do this safely. The decisions that took me to the Cozy were
a) find a fun and different plane that can use the IO-360 I have after selling off the BD-4.
b) flip through the KitPlanes index and narrow it down to a short list - something unlike the PA-12, with a good safety record and fun to fly. I ended up looking at RV's, the T-18, and oh yeah, the Cozy IV.

The final screening was looking for a suitable project. Many or even most kits are never finished, and the completion rate for plans built is said to be less than 50%. Therefore, the optimal move is to find and assume an unfinished project with great workmanship. I ended up networking into the Cozy builders group and its chief guru referred me to a good candidate project. Attached are pictures showing the condition of this project when I did the pre-buy (most parts made, stored uncovered in a dusty hangar) and when delivered to me. There are a lot of pictures, so the files are zipped.

As of 6/09/2023, my progress is as per the attached spreadsheet. Bottom line, some odds and ends, the engine install and then configure the panel. Add 100 hours for final paint and I'll be ready for a move to the airport and inspection.

The original builder had a write up on similar lines...

Why Build a Cozy MKIV? 04-26-2009

My father was a pilot both in the Navy and commercial airlines, and I've had the bug since I was a kid. I had planned on taking lessons and working towards my Private Pilot certificate whenever I had cash to spare.But, as I started planning out this dream, I ended up spending a lot of time thinking about the future and what that certificate would do for me.Rental rates are terrible, (barely) affordable Cessnas are slow and out of date, and there's just something about owning your own plane. I want to be able to go up whenever I like, without answering to another owner, timeshare partner, or invoice.

Buying an aircraft is a lot like buying a car. You have a number of choices, each with different features in terms of safety, comfort, and speed. The problem is that a 1990s Cessna with a decent (but not extravagant) avionics package can run over $100,000, and even a very old, 1960s Cessna can run in excess of $30,000. Mortgages are long enough that these are relatively affordable, but when I did the math between speed, age, features, range, and capacity, I concluded that I wasn't getting enough for my money. It took a while before I came around to the idea of building. I suppose I figured it was a "weird" thing to do - nobody in my neighborhood was building a plane. No, that was something those guys do out on the Salt Flats - you know the ones, the same guys on TV building trebuchets to fling washing machines or "model" rockets bigger than a car. The kind of thing you'd love to do, but you don't know anybody who has actually done it, and all your friends look at you oddly when you talk about it.

As it turned out, once I started asking around, everybody seemed to know somebody who knew somebody who was building, or had built, an airplane. Weird. I live in Connecticut, not Utah. We don't have any salt flats. What's more, I found that there were even more building choices than buying choices - kits, plans, quick builds, aluminum, composite, weird mixes of both, etc. I was overwhelmed by the choices I had to make. I spent literally months researching the options, reading manufacturer sales materials, Web sites maintained by other builders, magazines, and anything else I could get my hands on. In the end, I chose a Cozy MKIV for the following reasons:

1. Composite construction. There's a saying: Composite aircraft are built; aluminum aircraft are assembled. Well, I've never built an aluminum aircraft, but I love working with wood because it's so malleable, and composite construction feels much the same. It's very tolerant of slight variations between builders. Have a bit of a low spot? You can easily fill it. Parts slightly out of alignment? Fill with flox and BID tape over it, and it's just as strong. That's not to say you don't have to make things correctly. But you work the material, you carve the foam, and you shape the finished surface. It feels very much like sculpture. It's also very refreshing to see materials that are so weak by themselves (namely crumbly sheets of foam, cloth you can pull apart with no effort, and liquid glue) come together with such simple techniques into such immensely strong structures that you could quite literally park a car on them.

2. Safety. The Cozy MKIV is a "canard pusher," which uses a positive-feedback front airfoil (the canard) to lift the nose for pitch control, rather than an elevator pushing down the tail. This is not only very efficient, it's also very safe. By setting the canard at a higher incidence angle than the main wing, the aircraft can be made more or less stall-proof. The canard will stall first, dropping the nose back to a safe attitude before the main wing itself stalls. This produces a gentle "nose bob" effect. The clean lines of the aircraft also give it an excellent glide ratio (15:1!), and it climbs to altitude quickly (1500fpm). One can reach 10,000 ft in just a few minutes, and from there glide 30 miles during an engine failure. Name a Cessna or Piper that can do that!

3. Performance. In addition to reaching cruising altitude very quickly, the Cozy is fast. With a turbo rotary engine and a willingness to burn some fuel, one can easily cruise at 200kts+ with a maximum range of up to 1000 miles. That means it is actually possible to use this plane for realistic, cross-country flight operations. I have family and friends all over the U.S. and Canada, and love to travel, so a fast means of transport is a Good Thing (tm).

4. Cost. This has actually risen sharply since I started building. At the time I started building, the plans suggested a budget of $15,000 each for the airframe, engine, and avionics, or $45,000 total. But rising fiberglass, aluminum, and epoxy prices, plus inflation in general, have pushed this number much higher. Today I think it would be safe to double the airframe cost, and add at least a bit to the engine and avionics since few builders install the bare-minimum they can find. Still, for $60k (about the price of a mid-range BMW) you can get yourself a brand-new aircraft capable of 200kts+ at 10,000ft with 1000mi of range. You can even do your own maintenance. Those are good numbers in any book!

5. Support. The Cozy has a big following, and there are a number of good Web sites and mailing lists with other builders answering questions, and sharing information, photos, and experiences. When there's something you don't quite understand in the plans, it can be very helpful knowing that you can ask for clarification on a forum, or visit another builder's site who describes how s/he resolved the issue. Update: I started this project in 2005, and I'm now most of the way through the build. I've had a few "holds" placed on the project due to work, life changes, and moves, but I'm happy to say that the bulk of the airframe is now complete. With luck and hard work, I'll be flying in less than a year. After four years and over a thousand hours of build time, I'm now convinced I made the right choice!

  Dec 31, 2025     Project Selection - (40 hours)       Category: C01 Introduction

This entry describes events of Q2 and Q3 2018. I want it as the display entry for the builder's log, so I date it 2025.

I am the 3rd owner of Cozy project #1147, having acquired a "mostly" complete hull, wings and canard. This log is organized by chapters of the 2-volume set of plans, and includes entries by both prior builders and me.

Prior Builder. Chad Robinson is a software designer and developer with an unstoppable personality and a gift for precision. As his first build he picked the Cozy Mk IV, a plans built airplane that will take 2000-4500 hours to complete. He launched this project in September 2003, working out of a shop around New London, CT. At the same time that I was active in the Hartford EAA and networked with the DAR's and homebuilders throughout the state. Even so, I did not know Chad - he was working down on the shore and seemed largely outside the EAA networks.

Eventually a big family and a growing business cut into his build time and Chad sold the project to Craig Westwood, a first time builder in Athens, GA. At the time of the sale this project was inspected by Marc Zeitlin, a highly regarded aeronautical engineer who specializes in canards and does 10+ canard condition inspections each year. He gave #1147 a clean bill of health at the purchase by Westwood. Craig Westwood bought the project, spent some time sanding and thinking about components, then decided he wanted a plane in which he could learn to fly. He bought a flying Cozy and sold this project (removing some high value parts he plans to use). I was referred to this project by Marc Zeitlin. Since then I have been pleased by the work of Chad Robinson and wished that Craig had better documented his holding period actions.

Craig and I hammered on a price for a while, and I probably paid too much, but better to pay a mediocre price for a great project than a great price for a mediocre project. Then we had to find the right shipper, and that occasioned a renegotiation. The airplane was delivered via a specialty trailer, with a hydraulic system for raising and rotating the aircraft. Neat!
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Sidebar on Resale Values
High quality homebuilts are the great bargain in aviation - a pristine 20-year-old home built might sell for the cost of the used engine. Unfinished, engine-less projects go for less than the cost of materials - yep, all that labor adds zero value. I've been a happy team player working on airplanes where all or most of the starting project came free to my EAA chapter. We worked as a team, got the airplane flying, and sold it on to a new owner. My favorite project story is a happy little acrobatic biplane donated to the chapter by a widow. We got it back in the air for less than $10,000 and sold it for our cost plus a young eagles donation. The plane is still zipping around and everyone is happy to see it getting loving care and attention.
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  Oct 15, 2003     Plans - Modifications - (3 hours)       Category: C01 Introduction

Following is a thumbnail description of the modifications made to the plans. All mods are well-known in the builder community and accepted as enhancements that do not compromise safety. Almost all of the mods had been made in the project as I received it, and were reviewed during a pro-purchase inspection by Marc Zeitlin, an expert in the Cozy. For each of the mods, see also the builders log of construction.

1) Forward-Hinged Canopy. I expect to regularly fly with a passenger, and wasn't very impressed with the side-opening canopy. If left unlatched, a side opening canopy is a potentially fatal problem. Front opening is easier for getting in or out, or when I something from the cabin, or happen to the on the wrong side of the plane! I installed a forward-hinged canopy using two car trunk hinges with built-in gas struts. They were designed for a heavy trunk, and easily support the weight of my canopy. To attach it, I added reinforcements for the attach bolts, and additional plies of carbon fiber for stiffness to keep the canopy from swaying as it's lifted or lowered. The finished assembly looks and works great, and I'm quite pleased with it.

2) I also installed retractable steps on both sides of the fuselage. These are nothing more than solid rods in tubes with a pin inside the canopy to move them in and out - very much like door latches, actually. This provides a lower drag, more durable solution than the plans step, and a step on both sides of the fuselage.

3) Higher Canopy and Turtleback. The plans Cozy was built to fit its designer, who was closer to 5'6" than my 6'. Additionally, I have short legs and a long torso. In an RV I fly with no cushion to gain an inch or so of extra room. A higher canopy is a common mod that's well documented in the builder community, and others report it works well. The back seat of a Cozy looks like a seat, but is typically used as a trunk. I've done three things to make the back seats more comfortable and usable. First, I lifted my turtleback nearly 2 inches when I installed it. Second, I spread it slightly wider than plans to give more feeling of headroom. This makes for a taller, flatter canopy, and a different look and feel. There is a drag penalty for this, but I understand it does not materially affect handling of stall characteristics. Third, I have larger windows for the rear passengers to improve their visibility.

4) Electric Pitch Trim, Landing Brake, and Nose Gear Retract. All three systems are manual in the plans. Adding small servo motors is a common modification, done with components agreed in the builder community. The Strong Pitch Trim System connects to the elevator surface on the canard, running to a bracket floxed onto the fuselage wall just forward of the instrument panel on the passenger side. The speed brake cable and bellcrank was replaced with a small actuator motor, using the plans modification shared on the builders group, placed behind the front passenger seat back. The Jack Wilhelmson Nose Lift is the one change requiring a manual back up - there is a manual extension rod that runs through a bronze oil-impregnated bushing in the instrument panel, a universal joint and another bushing through the face of F22 and then through a universal joint to the top of the lift.

5) Larger Nose Hatch. The slightly larger forward hatch (located atop the brakes) makes for easier access during the build and easier service in the future.

6) Car Seat Head Rests. The design calls for large "triangles" growing from the top of the front seat back, padded for headrests and potentially providing rollover protection to the occupants. In a common mod, the triangles were ommitted, the canopy was reinforced with additional plies of carbon fiber and I used auto head rests.

7) Cozy Girrl Strakes. The Cozy Girrrls' swept-forward strakes are a common mod that delivers a storage area at shoulder height. The perception of shoulder room is very welcome and comes at no discernable change in the center of lift or structural integrity - again, as per the builder community.

8) Upgrade to Matco brakes. The plans call for the use of Cleveland #199-152 Super Heavy Duty brakes and 5” wheels with the main landing gear. This has been the source of controversy for several years. Many builders, including some who are aeronautical engineers, have disputed the use of those brakes. Nat Puffer, the designer stands by them and doesn't like the idea of replacing them with the MATCO W-51 brakes with the 5” tires. J. D. Newman, of Infinity Aerospace, sells a nice package of wheels, brakes, axles, tires, tubes and master cylinders, for about $1,600. Many of the Cozy builders use the MATCO package. The MATCO system is a triple-puck system that, as engineers tell me, is better able to dissipate heat and handle the high landing speeds of the canard aircraft, as well as comply with the FAR part 23 brake requirements. Marc Zeitlin, expert in the Cozy, writes; “Previous calcs have used 80 kts for an aborted takeoff, but at gross weight, forward CG, and/or high DA's, this is optimistic. You might be indicating 72 kts, but on a high DA day in Durango, CO, your GS could be 86 kts. Even 80 kts is a bit optimistic in those cases. In this case, you need a bit over 300K ft-lb of energy absorption/wheel (not ft/lb, not lb). The 5.00x5 MATCO heavy duty triple puck brakes are the ONLY 5.00x5 brakes that have the capacity, per any of the MFG's claims.” J. D. Newman of Infinity Aerospace also does the math and provides a similar explanation on his website for the MATCO system.

9) Replace Nylaflow brake lines with SS/TFE and hard lines. The project arrived with Nylaflow installed as per plans. Now, stainless steel braid over a Teflon-lined hose from Aeroquip runs from brake up the gear leg into the fuse, then hard lines (aluminum tubing) along the fuse walls forward, then the SS hose to the brake cylinders. Cleveland brakes installed as per plans, but then discarded and gear legs modified to use the Matco brakes. New gear leg fairings have an embedded fiberglass tube providing larger conduits for the brake lines and any temperature sensors I choose to run. These SS hoses could handle 3,000psi as opposed to the 1,000 psi or less that the Nylaflow would handle. Since we could generate up to about 1,500 psi brake pressure, I felt that this was a good move—which is also being used now by more builders. I used Aeroquip AN3 hose with AN3 fittings. Of couse, I had to get Aeroquip adapters from the AN3 to the 1/8” NPT connections of the Matco master cylinders, wheel cylinders and parking brake. I also used a pair of AN3 90 degree bulkhead connectors to go through the LGBs. It was a bit pricier than the nylaflow, but I felt better about doing it this way.

10) Main gear fairings. To install the upgraded brake lines I had already cut the minimal shaping already done to the main gear legs, and decided the repair should address the drag coming from the main gear. These planes fly at about 2 degrees nose-up at cruise, and in a better world I would have determined and built the fairings for minimal drag at that AoA. Instead, I eyeballed a good alignment with the expected airflow. I cut the back 1" off the legs as delivered, avoiding the weight-bearing "hoop". I selected an airfoil shape and made templates which I used in building a new profile and trailing edge. For minimizing drag, the optimal ratio of length to thickness of a strut should be between 4-1 to 6-1. These fairings may add minute amounts of structural strength and weight, but at the cost of still more stiffness - this plane will jolt you on a hard landing. For minimizing drag, the optimal ratio of length to thickness of a strut should be between 4-1 to 6-1. I believe I achieved it with the selected NACA airfoil.

11) Pitot, landing and taxi lights in the nose. Essentially the plans pitot system was installed through the foremost nose bulkhead, with an intake point in the center of the nose under the landing light lens. The aluminum tube was wrapped in a heat tape, with the temperature rise, amperage and wiring tested on the bench. Landing and taxi lights were placed in the nose rather than in the belly under the pilot's seat. Placement under the pilot's seat would create a hole, a draft, and drag. Several other builders who are now flying have placed lights in the nose—Tim Lumpp, Marc Zeitlin, Joe Hull, Yair Gil—as well as several others who are not yet flying. Each has a slightly different approach. Mine is similar to others - I purchased a small LED light bar intended for off-road vehicles, then modified it to better fit the space available in the nose. A number of lenses were shaped and fitted, and the best one was put in place with adhesive, then faired with a wood flour mix.

12) Hidden Rudder Bellhorns – The wings, as purchased from Dennis Ohlman, came with the hidden rudder bellhorns rather than the plans ones. The plans bellhorns stick out of the end of the wing/winglet and are susceptible to being bumped by uninformed passers-by and bent, plus they can add a little extra drag in-flight. The hidden bellhorns work as well without the problems. The procedures for building and installing the modification were created by the Rutan Airplane Factory (RAF) for use in the Long EZ and were used by Ohlman.

13) Proseal for fuel tanks. The original builder intended to use an auto engine, and to use auto fuel. The Proseal is ethanol-proof, and I am fortunate to have had someone else work with that mess! (I used ProSeal to repair wet wing sections on my BD-4, and declare it pilo-phillic - it loves sticking to arm hair!)

14) Nosewheel Doors – John Slade, hangar mate of the first builder, created nosewheel doors mounted by piano hinges flanking the wheel well. The hinges are mounted to two strips of plywood (one for each side) behind which are mounted 10 aluminum slugs (5 per side) which are drilled and tapped for AN3 washer-head bolts. These two strips were floxed and glassed into the sides of the wheel opening. I copied what most builders were doing and built a very simple mechanism with door stops to hold the doors even with the outer skin, and a screen door-type spring that pulls the doors closed when the wheel is retracted. Doors are held open by that same spring when the nose wheel is extended. The door opening is also slightly tapered so that the air stream can assist in keeping the doors open when the gear is extended. The doors were molded by using a foam plug shaped as needed to hide the wheel. Glass was laid-up over the foam, and then most of the foam was sanded or cut away. The hinges are sandwiched by the glass and reinforced by AN3 washer-head bolts through the glass and hinges. Slade had used the design on his own plane and was copied by several builders, including Joe Hull, Wayne Hicks, Tim Andres, Skip Schneider and others, including Long EZ and Berkut drivers. Tim Andres and Jerry Schneider used more complicated closure mechanisms than the others (Tim later changed his), but this project follows the simple design.

  Sep 30, 2003     Plans - purchase, review & update - (7.5 hours)       Category: C01 Introduction

I ordered the plans while away on business, and couldn't wait to get home when my wife called to tell me they had arrived. I also ordered the free catalogs from both Wicks and Aircraft Spruce. I've heard a number of stories about the quality of service from these two vendors, so I'll try both and see what happens. The Robinsons are officially building Cozy MKIV Serial #1147! I like the sound of that: 1147... 747... Get it

I have a tendency to rush things, so this project will in part be a test of my patience. I have decided to carefully read every word of the plans several times before beginning each step, and I'm not about to skimp on the introduction. It looks to me like I need to get some post-it notes and go through the newsletters to identify areas where the plans need to be updated. Update: No worries about patience. There is so much wait time between steps while things cure that I'm automatically prevented from rushing things.

While reading through the plans, Nat makes it very clear that he frowns on major modifications. I fully support his reasoning, but I'm going to go with some minor changes that aren't as controversial (and perhaps one that is). For example, I do not intend to widen the fuselage, but I will probably install an electric pitch trim system, a joystick with more controls on it (to control the trim), and a few other things. There are a number of builders who have successfully made these modifications, and some are even endorsed by Nat in the newsletter. I've decided that every decision I make will be based on the knowledge that my children will likely be riding in back. Safety first!

The Cozy plans are not the end-all answer to building this plane. There is also a newsletter, and changes to the plans for safety and other reasons are published there. It is therefore necessary to go through the plans to update them. To that end, I've purchased a glue stick, a pad of airmail paper (which is very thin) and a few pads of Post-It notes, and will make my modifications that way. The cost listed for this step went to those supplies.

First, I made a list of all of the modifications for consideration. These are spelled out on a separate page. Next, I went through all of the newsletters, checking of plans changes as I made them. Fortunately, I have the "rev. 3" set of plans, so not many were required. It still took a while! I was diligent in reading every word of each newsletter because I wanted to pick up tidbits, like additional recommended tools. I'm glad I did - some of the letters contained useful details. I will probably end up getting this all again when I go through the electronic format mailing list archives, but what the hell, it's a good first step

  Apr 15, 2018     Project Purchase - (100 hours)       Category: C01 Introduction

Here is the time and expense involved in the project selection and purchase:

Date Hours $'s
Monday 6/18/18 24.0 2,500.00 Visit, inspect, negotiate, settle, and down payment
Sunday 7/29/18 8.0 8,000.00 arranging for moving, balance of payment
Friday 8/10/18 4.0 1,440.00 moving services (Rocket Racing League truck)
Wednesday 6/20/18 12.0 project meetings w current builders (Tampa + Pilot Country)
Wednesday 2/15/17 16.0 250.00 Sport Air workshop (Composites)
Thursday 2/15/18 16.0 250.00 Sport Air workshop (Electrical)
Saturday 6.0 phone consultations with Zeitlin, Westwood (seller) and email with Chad Robinson (original builder)
Sunday 7/15/18 24.0 15.00 x-ref project plans to build log, checking for completion

My total project acquisition cost was $12,455. Chad Robinson documented costs of approximately $31,500. Back out the parts removed by Craig Westwood and it comes to costs of approximately $29,000. Wherever my total costs end up, add $16,545 ($29,000 - $12,455). I'll also use an audio panel I have lying around, and the tools and materials in the shop - no charge for those. Bottom line, there will never be a precise fix on the cost of this plane, but it will be more than I want to admit.