The Very Light Jet (VLJ) market is seemingly one that has always had a great future ahead of it.
One need look no further than the Eclipse 500 to see the divergence between the promise and reality of this harsh segment.
The economic downturn of 2008 and the demise of charter operator DayJet, the Eclipse 500’s largest customer, sounded the death knell for Eclipse Aviation.
While the Eclipse brand’s new owner, One Aviation, has continued serial production of the type with the 550 and the Project Canada stretched variant, current orders are nowhere near the backlog peak of more than 2,500 for the original 500.
Into this barren landscape a new VLJ has sprouted: the Cirrus Vision Jet. Launched in 2006 as the SF50, the single-engined VLJ received US Federal Aviation Administration certification in October 2016, with European Aviation Safety Agency certification the following May.
Model is aimed at SR-series pilots looking to upgrade
Jeremy Dwyer-Lindgren
While “sprouted” might be a strange term to use in a flight review, the Vision Jet’s roots stem from Cirrus’ extremely successful series of piston-powered singles – the SR-20 and SR-22. Rather than developing a piston twin or turboprop to offer enhanced performance, Cirrus jumped into the deep end of the pool with a single-engined turbofan.
While the marketplace will determine where it flourishes, the Vision Jet is aimed squarely at current SR pilots looking to move up.
DESIGNED FROM INSIDE OUT
One trait that has helped differentiate Cirrus’ piston offerings from those of legacy manufacturers is their large and airy cabins. The Vision Jet continues this signature trait. The cabin’s cross section is weighted to provide ample room for the first two rows of seats, two seats at the instrument panel and two in the middle row. The middle row has a small central aisle to access the third row, which features one full-size seat and two child seats outboard.
The full-size third row seat can be moved longitudinally to any of three positions, to optimize cabin configuration. All passenger seats are removable, much like those in some minivans. While dimensionally the Vision Jet’s cabin is smaller than the Eclipse’s, its layout and large windows made it feel slightly roomier than its twin-jet rival. One safety feature that sets Cirrus offerings apart from competitors is the Cirrus Airframe Parachute System (CAPS). It is standard across the entire range of aircraft, and Cirrus felt it was essential that the Vision Jet also come equipped with CAPS.
Aircraft design is an exercise in choices and compromises; here, the large cabin and single engine largely dictate the Vision Jet’s unique configuration.
Additionally Cirrus wanted the aircraft to fit into T hangers found in the US. While not standardised, as a rule of thumb T hangers limit wingspan to about 12.5m (41ft) and aircraft length to about 9.75m. Rather than bury the engine in the aft fuselage, like the Diamond D-Jet, Cirrus choose to put it on top of the aft fuselage in a configuration reminiscent of Germany’s World War II-era Heinkel He 162.
Engine efficiency should be increased by this arrangement, as there is no inlet ducting to contend with. To keep the empennage out of the exhaust stream, either a “V” or “H” tail configuration was dictated.
Rather than adopt an H tail like the Heinkel, Cirrus chose the more visually appealing V tail. In theory, a V tail design should offer reduced drag compared with a conventional tail configuration, as each surface does double duty. In practice, this advantage is seldom realised as the size of each V surface must be increased for acceptable stability and control characteristics. Additionally, control linkage and actuation schemes are more complicated compared with conventional tail configurations. Finally, V tails, with their large effective dihedral, may be prone to adverse Dutch roll characteristics.
Recently FlightGlobal was given the opportunity to see how the Vision Jet performed on a two-leg ferry flight from Fresno, California to Little Rock, Arkansas. I accompanied Matt Bergwall, Vision Jet product manager, as he performed the pre-flight walk around inspection of N52CV at Fresno.
The Vision Jet does have a certain “ramp presence” with its large cabin and piggy-back engine. The Vision Jet features fully-booted wing and empennage leading edges, giving it authorisation for flight into known icing conditions (FIKI). The engine inlet uses bleed air for ice protection with a TKS spray system for the windscreen.
YAW AUGMENTATION
Of particular note during the inspection were two ventral fins mounted below the V tail with moveable control surfaces, which formed a truncated “X” when viewed from behind. These were the control element for the yaw stability augmentation system (yaw SAS). As mentioned above, lateral directional stability can be a concern for V tail designs, typically compensated for by an active yaw damper (YD). For any number of aircraft, there is a pilot observed limitation prohibiting take-off or landing with the YD engaged. In the Vision Jet, the YD is automatically engaged climbing through 200ft AGL and disengaged descending through 200ft AGL, as determined by GPS position data.
To provide needed stability and control near the runway, the yaw SAS steps in. Controlled by the autopilot (AP), its operation is transparent to the pilot and allows for cross-control inputs in crosswind landing scenarios. The pre-flight inspection was straightforward and no more involved than that for any light aircraft.
Access to the cabin was through a large clamshell door that incorporated steps in the lower half to ease entry. The forward left-hand seat was slid fully aft on its tracks, allowing me to sit directly in the command seat. Once belted in with the three-point harness, I slid the seat forward, allowing Bergwall and Cirrus safety pilot Jason Dillion to enter the cabin.
Bergwall strapped into the forward right-hand seat with Dillion siting in the second row. The flight deck is well-arranged in a somewhat unique manner. The forward panel is dominated by two 14in GDU1400 display units, including one for the primary flight display (PFD) and the other for the multifunction flight display (MFD). Aft of the screens is a bolster, housing switches as well as three touchscreen controllers. The AP control panel and single thrust lever (TL) are placed on the centre console. In what I found to be an outstanding feature, all emergency controls are located on the overhead mounted “emergency panel.” Most prominent among them is the CAPS actuation handle.
HIGH-PRICED SALOON
Engine start controls, just forward of the sidestick, seemed more like the ignition button for a high-end Audi or Jaguar car than a turbine-powered aircraft. Once cleared by ramp personnel, the engine knob was turned to “RUN” and the engine button pressed to initiate the start sequence. The full authority digital engine control system made the engine start sequence essentially automatic, with the pilot only monitoring for any abnormalities.
Time to idle engine speed was about 30s with inlet turbine temperature peaking at 650ºC, well below its limit of 1,000ºC. The flaps were set to the intermediate 50% position, and the parking brake released for taxi to Fresno’s runway 29L. Initially I found taxiing the Vision Jet tricky as it has a fully castering nose wheel. I would have expected an aircraft in this category to have nose-wheel steering, but Bergwall assured me that upgrading Cirrus piston pilots are quite used to this scheme.
Lower parts of "X-tails" are moveable fins, part of the autopilot-controlled yaw stability augmentation system
Jeremy Dwyer-Lindgren
Prior to entering the active runway, Bergwall reviewed take-off contingencies. In the very unlikely event of engine failure our course of action would be determined by our altitude. Below 1,000ft AGL? Land straight. Between 1,000 and 2,000ft? Deploy the CAPS. Above 2,000ft? Initiate an air start while turning towards an emergency landing field. Once cleared for take-off, I advanced the TL to the full forward TO detent. On the hot 35ºC day, TO power stabilised at 62% of standard day rating, as indicated on the thrust display on the engine indication system. I first used differential braking to maintain runway centreline with the rudder becoming effective around 40KIAS. At 90KIAS a firm aft pull was needed to establish the 5º nose-up TO attitude. Pitch force changes caused by gear and flap retraction were easily countered with sidestick actuated pitch trim. At 3,000ft AGL, in a clean configuration and above obstacles, I retarded the TL to the maximum continuous thrust (MCT) detent.
CLEARING THE SIERRAS
After an initial climb speed of 150KIAS was established, I engaged the AP. The TL was left in the MCT detent as we climbed above the Sierra mountains en route to Denver’s Centennial airport. Passing FL200, the climb profile transitioned to a constant Mach speed of 0.313. Our TO weight had been 2,692kg (5,935lb), just below its maximum of 2,722kg. Temperatures during the climb were 20ºC hotter than standard, with the Vision Jet leveling at FL270 about 23min after lift-off.
I kept the TL in the MCT detent after level off, with indicated thrust now at 34%, and the Vision Jet accelerated to and stabilised at 182KIAS. Test day conditions (ISA +15ºC) showed a Mach of 0.46 and a fuel flow of 59gph, giving a true airspeed of 287kt. Observed performance agreed well with Cirrus data, its listed 300kt top speed well within reason. To sample a long-range cruise condition, I next set fuel flow to 45gph. Indicated thrust was now just 27%, with the Vision Jet slowing to 149KIAS. An indicated Mach of 0.38 gave a true airspeed of 235kt.
With the AP still engaged I returned the TL to the MCT detent to hurry us along, as I unstrapped and went to sit in the second row of seats. Up to this point I had been wearing a noise cancelling headset, and with it off I was able to get a feel for the ambient noise level. I was able to carry on a conversation with Dillion at normal voice levels. Subjectively I found it louder than the light jets I had flown, but undoubtedly quieter than turboprop cabins. The Vision Jet’s 6.5psi pressurisation system kept a comfortable cabin altitude of 7,540ft.
After I returned to the flight deck, Bergwall pointed out an approaching line of thunderstorms with tops around 35,000ft. We would not be able to overfly them, so steered through the clouds. This challenge presented an opportunity for the Vision Jet’s Garmin 3000-based Perspective Touch avionics package to shine. XM satellite weather gave us the big picture of the convective activity, while the onboard weather radar allowed us to refine our path close-in. I especially liked the Perspective Touch’s large display area, enough to have a full screen PFD, as well as a map, approach chart and EIS panels. Additionally a Vertical Situation Display can be shown, which graphically depicts upcoming crossing restrictions. Crossing the Continental Divide, we cleared the thunderstorms and started our descent for landing.
APPROACHING STORM
Our initial plan was for a coupled instrument landing system (ILS) approach to Centennial’s runway 35R. Numerous prior flights in Garmin-equipped aircraft had allowed me to load and activate the approach procedure with little assistance from Bergwall.
I found that the own-ship position presented on the geo-referenced approach plate greatly enhanced situational awareness. As we manoeuvred downwind, a large thunderstorm approached the field. To ensure we landed before the storm hit, we abandoned the instrument procedure for a visual approach with a shorter final. As our altitude on the downwind approach was too high, I immediately dropped the gear and lowered the flaps to 50%, which slowed the aircraft through 190KIAS. I found the sidestick-actuated pitch trim rate was too slow to relieve the changing pitch forces. Bergwall suggested I use the pedestal-mounted, manual pitch trim wheel instead, which ironically was too effective and caused me to overcorrect. Many aircraft have variable trim rates, some simply based on flap position. Cirrus may find that a variable-speed pitch trim system will enhance the Vision Jet flying experience.
With 100% flaps, our approach speed was 85KIAS, equivalent to the reference landing speed plus 10KIAS. This was perhaps the slowest approach speed I had ever flown in a jet aircraft, one that allows the Vision Jet to fit in with piston aircraft at small airfields.
On final, 30% indicated thrust held our approach speed. With the TL at idle at about 20ft, I started a slow flare manoeuvre. Initially a tad high, I milked the Vision Jet down to the runway, where the trailing link main landing gear ensured a soft touchdown. Toe-actuated wheel braking quickly slowed us for runway turnoff and taxi to transient parking. During the taxi I found having the thrust above idle gave me enough momentum to negotiate corners with differential braking and castering nose wheel. After shutdown, I noted the 926nm (1,715km) flight had taken 2h 57min while burning 715 litres (189gal) of fuel.
RESIDENT SAFETY
Dusk was approaching as we started the Williams FJ33 engine for our flight to Little Rock, Arkansas. The wind had shifted since our arrival and we taxied to runway 17L for takeoff.
Pacing on takeoff was similar to my first one in Fresno, the higher elevation being compensated for by the cooler temperatures and lighter gross weight. Dillion was based in Denver and wouldn't be continuing with us on our journey. The climb to FL270 took approximately 26min, where MCT power was left for high-speed cruise at 173KIAS to Little Rock. A fuel flow of 54gph gave us a Mach of 0.441 and resultant true airspeed of 273kt.
The nearly 2h at cruise altitude gave me time to reflect on the Vision Jet’s strengths. The Perspective Touch avionics package is by far one of the strongest, most capable systems I have experienced in any jet except for those found in current large cabin offerings. One unique feature, especially at this price point, is a daylight/infrared enhanced vision system (EVS). The EVS presents the forward IR view on the MFD, and should increase situational awareness in low light and obscured conditions.
Jeremy Dwyer-Lindgren
The Vision Jet’s safety features also set it apart. Resident in the Perspective Touch package, pressing the blue “LVL” button will roll the aircraft wings level and hold altitude. Additionally the AP’s electronic stability and protection (ESP) feature prevents roll as well as slow- and high-speed exceedances. The extremely reliable FJ33 turbofan should not be overlooked as a safety improvement over a piston engine. Finally, if all else fails, Cirrus’ proven CAPS is available to save the day.
CHEAP JET?
The descent and landing at Little Rock was uneventful, save for my making the last tight 90º turn into the ramp parking spot.
Some have commented that the Vision Jet is the “cheapest” jet on the market, and nothing could be more irrelevant. There is nothing “cheap” about the Vision Jet. It is a well-made aircraft with many strengths from an established manufacturer that has striven to improve safety in general aviation. It is the lowest-priced new jet available, but this does come at a cost. If flying higher, farther and faster is your goal, there may be better – and more expensive – options available. If you are an established Cirrus pilot looking to move up into something larger and faster, the Vision Jet will suite you to a “T”. Or should I say “V”?
Source: FlightGlobal.com
