Builders:Gregory W. Richter, Robert and Valerie Harris
Type: homebuilt experimental jet canard aircraft
Powerplant: 1 x Mazda 13B (early fit)
Significant date: 2001
According to homebuilder Gregory W. Richter, it was Chuck Kerber's flawless L-39 Albatros jet which inspired him the turbine powered version of the Cozy, which he appropriately called the CozyJet. "To answer the obvious question, of (...) how I got it all done, I'll defer to my ace mechanics: Robert and Valerie Harris who did the cutting, welding and splacking to turn my Clark Kent Cozy into the iron-pumping beast she is this week," explained Richter.
Test pilot Len Fox went through a very detailed shakedown that included the canopy popping open and a few other exciting things that a pilot might not handle with grace and speed. "Making the first hop in an experimental jet is no question a job for a professional test pilot and luckily, I have a friend who is one" said Richter, who claims that "Fox climbed out at 3000 feet/minute indicating 150 knots at 85% power on the first hop, and made a better landing than I did in my own plane."
"My take is to never make the first hop in a new machine—your love for the project will keep you in it long after you should have hit the silk and bailed out. Same reason that first flights should be semi-clandestine—you don't need an audience when you are working through something you'd hope would never happen. It was TOUGH watching someone else have all the fun, but I got in as soon as Len got the numbers down and haven't gotten out since."
N722's original fit was with a Mazda 13B engine from a 1992 RX7 car. With a whole stack of modifications, it's a very smooth and elegant way to turn a propeller, but the engine of choice finally turned out to be the General Electric T58, a turboshaft engine that turns the blades on Sea King choppers among other things. By removing the N2 section and fitting a tailcone, you end up with an extremely loud gas producer. The T58 conversion is insanely loud. After much theorizing and hanging about we came up with a reasonable understanding of why it's so loud. RV driver and fellow engineer Tom Lloyd figured out how to best remove the exhaust screech, and Robert Harris' fiberglass S Duct intake took care of the compressor noise.
The hush kit has got the sound level down to about where a Citation is at idle, although there's no hiding the flow noise on takeoff. "I thought 722 was destined to be the noisiest kid on the ramp, but with a little engineering, and more than a little help from my friends, she's sounds like just another Bizjet" said Richter. The cone and tailpipe were laser cut, rolled and welded by Brad Snodgrass, a fellow EFIS driver and an RV builder who also happens to be in the metals business. He figured the optimal alloy on the price/temperature curve to be Hastex, which is a swoopy high temperature stainless steel.
"Most jets are comlicated machines with long checklists. We all tried very hard to make 722 easy to fly and easy to operate" Richter explains. This is made obvious by the lack of breakers, switches and "the usual frankenstein collection of electrical yeehah". The PC board at the back handles switching, lighting, current limiting, fusing, pitch and roll trim, flaps (speed boards in this case), canopy alarm and essentially the whole airplane electrical system. Test pilot Fox noted that it was the easiest plane to operate he had ever flown—"throw the switch and go". 722's checklist is actually shorter than a single engine Cessna's! Now that the CozyJet is all wrapped up and headed for adventures unknown, what next? "Well, the rumor is true. We're building a 4 place jet", says Richter with pride.
Population: 1 (c/n 400) [N722]
CozyJet's interior sets new standards of excellence