Wednesday, December 1, 2004
The Klapmeiers’ vision enters the second generation
|For those of you who haven’t heard, Cessna was just recently dethroned as one of the top-selling general-aviation companies in the world. For the first two quarters of this year, the total number of Cessna Skyhawks and Skylanes was bested by Cirrus Design’s combination of SR20 as well as SR22 sales. In fact, the vast majority of Cirrus’ sales came from its showpiece, the new SR22-G2.|
The SR20 met with immediate success, and we all knew that it was only a matter of time before Cirrus introduced an upgraded model. Everyone speculated that a retractable might be the first improved airplane, but that wasn’t to be, and for some good reasons. The late Roy LoPresti, speed guru and expert on certification of both fixed and retractable-gear aircraft, explained the logic several years ago: “A retractable doesn’t always make sense if you already have an efficient fixed-gear design. The retraction mechanism is always heavier and more complex and adds quite a bit to production incorporation costs, and the drag reduction may not be that great. You’ll often realize only an extra 10 to 12 knots more speed, sometimes 15 knots. Certification costs are higher, as well, and of course, a retraction system is just one more system that can fail.”
For all of those reasons, both the Klapmeiers elected to concentrate instead on a horsepower makeover. The Cirrus SR22 was a logical next step, a 310-hp Continental IO-550N-powered version of the original design. The fuselage was the same, although the nose was pushed forward to accommodate the larger engine. Wingspan was increased 1.5 feet per side, adding 10 square feet of surface area, the better to lift 3,400 pounds of gross, 400 pounds more than the SR20. The SR22 also was an all-electric airplane, without a vacuum system.
The performance benefits of adding 55% more horsepower were immediate and predictable. Climb performance, always the primary beneficiary of any power increase, improved by 500 fpm to 1,400 fpm at sea level. Cruise jumped 20 knots, from 160 to 180 knots, vaulting the SR22 up into the Mooney speed class.
Useful load went up 220 pounds to 1,150 pounds, although some of that was lost to the higher fuel capacity, 81 gallons versus 56 gallons on the SR20. The SR22 almost immediately began outselling the SR20, causing 20% of existing SR20 customers to upgrade their orders to the more powerful airplane. By 2003, the new model was accounting for 80% of the Duluth, Minn., company’s sales in dollars.
Now comes the Cirrus SR22-G2. In this case, “G2” doesn’t allude to an exotic, long-range business jet, but stands for “second generation—because evolution shouldn’t take 50 years,” according to Cirrus. We can all agree on that. The SR22 utilizes the SIMPLE (Single Movement Power Lever) power system, a total integration of throttle and propeller control that allows the pilot to manage both parameters with a single lever.
The G2 incorporates a number of new features, refinements to the SR22 design that serve to enhance function and comfort. Cirrus paid attention to such things as door latches. General-aviation door latches have often been regarded as clumsy and inefficient, too often making doors difficult to latch and thereby increasing the likelihood that they’ll pop open in flight. The new Cirrus door-latching system is automotive in concept, providing easier closing and opening with the push of a single button. Cirrus calls the new system Secure Latch, and it even extends to the baggage compartment.
Engine mounts might not seem a logical target for improvement, but a solid engine mount can make the difference between a smooth engine and one that will send vibrations through the airframe and passengers. The G2 adopts a six-point mounting system, compared to four points on most general-aviation designs. The additional two isolators help secure the engine to the mount and avoid much of the fatigue associated with vibration.
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