One surefire way for airplane makers to get a lot more performance out of their existing designs is by adding a turbocharger. It's hardly a new approach. It's been popular since the 1960s. And just in the past few years Columbia, Mooney and Cessna have all introduced turbocharged models, all based on good-selling existing airplanes. So it was no surprise when Cirrus, which had in fact been openly talking about the possibility for a while, pulled the trigger on its very own turbo project, launching the SR22 Turbo Charged at AirVenture last summer.
Fans of Cirrus' iconoclastic reputation will be happy to learn that the company somehow managed to change the way such programs are done. While Cirrus took a highly unusual (maybe unprecedented) approach, like every other controversial path they've tread-think parachute; think flat panels; think The Jet by Cirrus-there were good arguments in this case too for why it made sense to go outside the box to get things done.
Of course, the conventional way of developing a turbo model is to simply (okay, it's not really simple at all) bolt on a certified turbocharged version of the naturally aspirated engine already on the airplane and make the necessary airframe changes, if any, to accommodate the increased speeds, altitudes and weights. In the case of four of the current (or emerging) production turbocharged airplanes, the Cessna Turbo 182 and 206, the Columbia 400 and the Mooney Acclaim, the airplane makers went with just that formula and came up with impressive performance increases. The Columbia 400 and the to-be-certified Mooney Acclaim can do around 235 knots true at 25,000 feet.
In developing its turbocharged model, however, Cirrus decided to modify the naturally aspirated engine it was already using on the airplane. So it partnered with aftermarket turbo mod house Tornado Alley in developing the turbo system, which earned an STC for it last fall.
The STC approach had risks: Would the airplane fly well enough at altitude to not need airframe changes? Would Continental honor the warranty on its very expensive engines given the modifications? And would the modification do everything, or at least most of everything that Tornado Alley promised?
The lure of the potential benefits of the STC approach apparently won out. One of those claimed by Cirrus is highly unusual and deserves mention. The company has all along said that by going the STC route on the turbocharger, owners would have the option of removing the turbocharger at some later point if 100LL avgas ever disappears without there being a suitable replacement, a scenario that Cirrus apparently believes is more likely than most other industry observers.
According to Cirrus cofounder Dale Klapmeier, the "engine warranty does not change" for the turbocharged airplane. "There have been discussions between Cirrus and TCM on the subject," Klapmeier said, but the bottom line is "that warranty claims are made just like every other Cirrus SRV, 20 or 22, and assuming they are a valid claim, things get corrected."
