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.