Cirrus single-engine jet could fly in two years

 - July 30, 2007, 10:45 AM

A “verification prototype” of Cirrus’s recently unveiled “personal jet” could fly within two or three years, according to company officials.

Cirrus Design executives revealed a mock-up of the long-awaited single-engine jet at company headquarters in Duluth, Minn., in late June. To date, the company has received $100,000 deposits for more than 150 copies of “The-Jet,” mostly from current customers of its piston SR20 and SR22.

Cirrus did not provide a firm price, performance numbers, or a development schedule for The-Jet, which Cirrus vice chairman Alan Klapmeier characterized as “a bigger, more capable SR22.” Though Klapmeier declined to reveal a firm price or specs for the airplane, he did say he wants the single-engine jet to have simple systems, pleasant handling, good short-field performance, a top speed of 300 knots, a range of 1,000 nm and a price in the neighborhood of $1 million.

“We are not trying to be a business jet,” he said. “This is not a VLJ [very light jet]. This is a personal jet and it is all about simplicity. When passengers get out of this airplane they can envision flying it themselves.”

Klapmeier characterized the first Cirrus jet that would fly as a “verification prototype,” a developmental aircraft located between a proof of concept and conforming prototype. “The goal of the first airplane is aerodynamic testing,” he said.

The company has already conducted extensive wind-tunnel testing on The-Jet, according to Cirrus vice president of advanced development Mike Van Staagen. “What we are really focusing on is the shape of the aircraft,” he said. “We feel we have everything we need to build the first airplane and fly it safely.”

Details Still Scarce
As disclosed at last year’s NBAA Convention, Cirrus has selected the Williams FJ33-4A turbofan to power the aircraft. Van Staagen described Williams as a “risk-sharing partner” in the jet’s development. No other key suppliers have been announced, although the mock-up features a two-screen instrument panel layout similar to the one that houses the Avidyne system in Cirrus piston airplanes.

However, Van Staagen said that the company was not necessarily committed to Avidyne on the jet. “We haven’t made any decisions yet,” he said. “We really want to develop the avionics along with the airplane. We have some pretty aggressive ideas as to where we want the avionics to go, but we don’t want to be chasing our tails at the end of the project putting in a whole new avionics system,” he said, making a veiled reference to the avionics problems at VLJ maker Eclipse.

The jet mock-up features twin clamshell doors and flexible tracked seating for five, as well as two jump seats for passengers weighing less than 100 pounds. It also has a heated external baggage compartment large enough for golf clubs, and a V tail and centerline over-fuselage engine positioning resembling the U.S. Air Force’s Global Hawk UAV. The engine will be canted at a 20-degree angle, descend along the slope of the fuselage and use vectored thrust.

Van Staagen said the engine positioning gives the airplane a more flexible center of gravity. “The idea is to make all variable weight as close as possible to the cg,” he said. “All fuel is in the wings and all seats are located over the cg, with the bags in back.” It also makes the engine easier to access and service, shields the cabin from rotor burst and any resulting structure fire and mitigates FOD ingestion and cabin noise, he said.

Referring to the engine positioning, Klapmeier said, “We didn’t do it just because it looks cool. In the end it has to make sense.” The humped fuselage allows for a virtual stand-up entry way and facilitates ease of entry and egress from the front and second rows. The front seats slide back parallel to the doors. Both front seats and the middle second-row seat have generous amounts of floor tracking. The middle second-row seat tracks aft 12 inches parallel to the jump seats in the aft-most part of the cabin, giving occupants increased shoulder room.

“We’re not building any airplanes that make you crawl to get into the front seat,” said Klapmeier, noting that 30 percent of the time the current Cirrus fleet flies with a single occupant.

Van Staagen said the company already has 80 employees and additional outside consultants working on the aircraft and that many of its key features, such as the trailing-link landing gear and the location of the whole-aircraft ballistic parachute system (it’s in the nose), have already been defined. He also said that designers were close to confirming a weight envelope of maximum cabin payload of 1,000 pounds or maximum fuel of 1,800 pounds.

Klapmeier said the wide envelope will allow operators to “maximize flexibility with fuel and payload” and hinted that full-fuel payload could be as little as 300 pounds. However, Cirrus continues to work through significant aircraft systems issues, including de-ice and cabin environment.

The aircraft’s single-engine design limits the amount of bleed air that can be diverted to de-ice and environmental systems. Van Staagen said the company was evaluating electrical wing de-icing systems but didn’t know “if any is [ready for] prime time or will be…in the next couple of years or so.”

“We know we can do it [provide anti-ice protection] with TKS [glycol] or the Goodrich boot.”

He said plans called for standard vapor-cycle air conditioning in the cabin and that properly sizing the system was of concern because of the amount of solar gain from the aircraft’s large windows.

Cirrus began serious work on The-Jet in 2003 at an off-site location the company calls “The Moose Works.” The current mock-up is the third iteration. The airplane is the culmination of almost two decades of looking at a potential personal jet market for Cirrus. The company began looking at the personal jet concept in the late 1980s, according to Klapmeier, when it investigated the possibility of powering its pusher-propeller VK-30 kit airplane with a Williams FJ44 turbofan. During the 1990s, Cirrus developed a turboprop variation of the VK-30, the ST-50, in partnership with Israviation; however, that aircraft never entered production.