Flight Test: G5 Cirrus SR22T
- Credit: PIL JAN17 FLIGHT TEST Cirrus SIN
Increased load capacity, enhanced performance, fantastic handling and advanced navigation aids make the ‘fifth-generation’ SR22 the best SEP tourer we’ve seen — full stop. Dave Unwin explains why (Photos by Keith Wilson)
“So Charlie, do you remember the last time we flew together?” Cirrus UK’s Charlie Kimbell replied, “Yeah, a Tiger Moth, out of Sibson.” For a moment we both contemplated the panel, which wouldn’t look out of a place in an airliner. “Hard to believe this is on the same SEP ticket!”
I first flew a Cirrus ? an early SR20 ? about fifteen years ago and, to be honest, the latest ‘G5’ SR22T looks the same, even though there are perhaps around a thousand changes. In fact, probably the greatest challenge faced by a Cirrus salesman is convincing prospective buyers that the new model really is that innovative.Some of you may be asking why there wasn’t a G4. Well, Cirrus is owned by CAIGA (the China Aviation Industry General Aircraft) and four is an unlucky number in China!
The aircraft in front of me on the apron at Cirrus UK’s Sywell base certainly looked familiar, yet I knew this really was a different machine from an early SR20 or the SR22T I flew in 2008. There are even differences between the 2015 and 2016 models.
The significant improvements are that the C of G envelope has been expanded and the useful load increased. The last Cirrus I flew (the 22T) had a useful load of 415kg and a slightly restrictive forward C of G. On the G5, not only is the envelope wider, but the maximum all-up weight (MAUW) has been increased by 91kg, allowing for the addition of a fifth seat.
However, and as with most other aircraft, if you do fill the tanks you won’t be able to put an adult on each seat, let alone anything in the baggage bay. Nevertheless, Cirrus deserves praise for achieving a difficult feat – increasing the MAUW requires strengthening the airframe, which increases the empty weight. Engineers managed to lose some weight by tweaking a bit here and shaving a bit there. They had to as the increase in MAUW also required a larger parachute, which needed a more powerful rocket, which weighed more… Truly, increasing an aircraft’s MAUW is a vicious circle.
As we walked out, Charlie explained that the 22 is available with either a normally-aspirated or turbocharged engine. The demo aircraft’s turbocharged engine is based on the same unit fitted to the last SR22 I’d flown, the Teledyne-Continental IO-550 air-cooled flat-six. However, unlike the earlier installation, which was ‘turbo normalised’ (i.e. set up to produce the same maximum power throughout the operational altitude range) the G5’s turbocharger delivers constant boost, to a maximum of 37in, all the way to 25,000ft, producing better performance and climb rate.
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The previous model used dual turbochargers and intercoolers supplied by aftermarket specialists Tornado Alley. The G5’s Continental TSIO-550K uses factory fitted units, runs 200rpm slower and has a reduced compression ratio, enabling it to run on lower octane 94UL. It’s noticeably quieter, mostly because the propeller is turning at lower revs.
The three blades sprouting from the highly polished spinner are of the increasingly familiar Hartzell Scimitar type. As with most aspects of the G5, the prop is quite advanced and the blades’ unusual shape is claimed not only to enhance airflow through the cowl inlets but decrease transonic drag and noise at the tips. Made from a carbon fibre/Kevlar combination, the blades are amazingly tough, as well as being more than five kilos lighter than those of comparable metal props.
The G5 is taller than the original SR22. The mainwheel track has been reduced by 49cm by decreasing the included angle between the undercarriage legs. This change in geometry has resulted in the G5 standing about five centimetres taller than earlier aircraft, which increases propeller and tailplane clearance and gives the machine more ‘ramp presence’.
The nosewheel is the same fully-castoring unit, while the wheels and brakes are now made by Beringer, who burst onto the aerospace market over the last few years. Their units fitted to the G5 are exceptional. The wheel hubs are CNC machined from solid aluminium then anodised red, while the brake calipers incorporate twin polished pistons. The discs are stainless steel and the braided lines Teflon coated, meaning the brakes are light but provide great stopping performance, while the wheel’s low-resistance bearings make it easy for a ‘single person’ to move the aircraft with a tow bar (although the relevance of this individual’s marital status is unclear to me).
All three wheels are closely spatted, and another small but significant improvement is that the spats now feature small doors that provide access to the valves for the tubeless tyres. There used to be little blue patches on the inside of the mainwheel spats for checking the brakes (if the patch has gone black, the brake pads have overheated and should be inspected as per the POH) but these days you get a warning on the primary flight display (PFD) in the cockpit.
Because of the castoring nosewheel, overheated brake pads are more likely than you might think. Imagine taxying for half a mile on concrete with a stiff ninety-degree crosswind – the downwind brake is bound to get hot. I think it’s high time that Cirrus looked at installing a nosewheel lock, which would take the load off the brakes. It could be as simple as a spring-loaded pin and a Bowden cable, or something more sophisticated using an electromagnetic system. Anything would be better than the current arrangement!
The wings feature the same stall strips, drooped leading edge (Cirrus call it a ‘cuffed wing’) Frise-type ailerons and large, single-slotted flaps as on previous aircraft, but the wingspan is almost a metre wider to cope with the considerably greater MAUW.
Although the airframe is primarily constructed in composite materials, Cirrus prudently decided years ago that those parts most vulnerable to ‘hangar rash’ ? such as the ailerons, flaps, elevator and rudder ? would be made from aluminium.
On either side of the fuselage just forward of the wing root is a small ventral fin. This is a vortex generator, which, as well as improving low-speed handling, ensures that as the wing approaches critical alpha the airflow initially separates at the root. Separation then propagates outboard to the tips so the ailerons continue to work after the mainplane has stalled.
This process is helped by the cuffed wing, everything outboard of the cuff is at a lower angle of attack, meaning the inboard part of the wing stalls first leaving the outboard and ailerons still effective. Of course, the same effect can be achieved with washout (twisting the wing downwards towards the tip), but then the incidence would not be optimised for the cruise.
The wing root fairings have been restyled in order to reduce drag, and I noted that the leading edge wing root air intakes for the cabin have been removed and replaced by an NACA duct on the starboard side of the cowling.
The SR22 is approved for FIKI (flight into known ice) and uses a TKS ‘weeping wing’ ice protection system. A glycol-based antifreeze solution seeps through porous titanium panels fitted to the leading edges of the wings, tailplane and fin – there are 133 laser-cut holes per square centimetre – while a ‘slinger’ ring on the prop coats the propeller and windshield. Earlier aircraft had a single fuselage tank, but now there’s a fifteen-litre tank and filler port for the TKS in each wing. This is a much better arrangement, as not only is it easier to fill and visually check the contents, but the amount of de-icing fluid has been greatly increased.
There is an intriguing pod under the port wing, carrying the thermal-imaging camera for the Enhanced Vision System.
So far I have listed ten or so changes. Most of the other 990 are either in the cockpit or hidden beneath the skin. Although the aerofoil is the same section as used on other Cirrus aircraft, the mainspar is now carbon-fibre and the use of this material, along with some other changes, has produced a wing that is 23kg lighter and substantially stronger, despite being larger.
Another major design change is that the useable fuel capacity has been increased from 307 to 358 litres, allowing you to cover up to an extra 180nm. However, you must keep in mind that this machine burns around 66lph (more than a litre a minute!) at max cruise.
The overall finish is good, but there were a couple of small areas already looking slightly shabby. As the test aircraft had only logged around 100 hours and had a cost getting on for a million bucks, is this satisfactory?
Charlie suddenly said, “Watch this” and with the air of a conjuror pressed the key fob, the doors unlocked and the interior lit up, just like a modern car. About time too! Access to the cockpit is very good, the doors are generously sized and open wide. The grab handles, steps and walkways are all well located, with the latter two being illuminated.
The cabin is quite roomy. As the rear seat backs can be folded forward and the front seats tilt backwards, there are good stowage options, particularly as the baggage bay is accessible in flight. The car analogy continues in the cockpit – there’s lots of leather, excellent ergonomics and it has that wonderful ‘new car smell’. Not only do the front seats adjust fore-and-aft over a wide range, but the rails they slide on angle upward slightly towards the front, raising the seat. I’m not overly tall, so I like this arrangement a lot.
On many GA aircraft, there is no vertical adjustment available as it is impossible to provide both this and adequate energy-absorption. Cirrus design has always been very safety-conscious and this arrangement provides a measure of vertical movement, while still allowing the seats to withstand up to 26g. Other inbuilt safety features include the well-known CAPS ballistic recovery system, an integral 3g roll cage and Amsafe airbag seatbelts, which are incorporated into the three-point harnesses.
Curiously, when I first sat down the seat didn’t seem that comfortable ? but it felt fine by the time we landed an hour later. The cushions have rather a thin foam core, sitting as they do on an aluminium honeycomb section built into the seat base for impact absorption during a CAPS landing. The seats are firm, but well shaped so there are no pressure points.
So, the pilot is well catered for, but what about the passengers? The cabin is quite big and the small skylight set into the roof makes it bright and ‘airy’. Each seat has an oxygen outlet and headset socket, factory-installed air conditioning is an option and other neat touches include magnetic headset holders and a pouch in the seat for your smart phone or tablet.
The main switch panel has been redesigned, and incorporates several new features. The switches are recessed to prevent inadvertent operation during flight and the entire unit is backlit. The main circuit breaker panel and alternate air selector are still to the right of the pilot’s right leg, although the parking brake is now below the panel in front of the P1 ? a much better location.
The instrument panel is dominated by the two large screens of the ‘Cirrus Perspective’ system, based on Garmin’s spectacularly successful G1000. Cirrus Perspective is amazing, frankly, and incorporates synthetic vision and enhanced (infra-red) vision, plus terrain awareness. The Nav/Comms are fully integrated and the transponder is ADS-B In and Out.
The Garmin GFC700 digital autopilot features Electronic Stability Protection (ESP), which prevents the aircraft exceeding predefined pitch and roll limits and provides high and low speed protection. Engine and fuel monitoring are displayed on either or both screens and there’s even an automatic hypoxia check above 18,000ft (if you don’t respond, the autopilot initiates a rapid descent). Now, one of these systems would be impressive ? that they are all integrated is remarkable. And that’s what makes this machine so special.
Most of the autopilot’s controls (including a full keyboard, so much easier for entering flight plans) and a GMA-350 audio panel are carried in a centre console that extends downwards from the bottom of the panel and then aft between the seats. Another great feature is you can actually prepare your flightplan at home on an iPad, then simply Bluetooth it to the Perspective system.
Below the avionics are the flap switch, position lights and oxygen system, followed by the boost pump, power lever (combined throttle/prop lever) and mixture control, and then the fuel selector valve. There is an armrest between the front seats, which hinges open to reveal a very useful storage compartment. Two things catch my eye – the blue ‘LVL’ button (punch this and the autopilot automatically returns the aircraft to straight-and-level flight) and the much higher limiting speeds printed next to the flap selector.
I always thought that ? for a fast piston-powered aeroplane with an air-cooled engine but no speed brakes or cowl flaps ? the limiting speed for the first stage of flap was too low at only 119kt. If a controller gave you a ‘slam-dunk’ approach, it was only too easy to end up with an embarrassment of either airspeed or altitude. First stage can now be selected at up to 150kt, a massive improvement. Second stage deployment has also gone up to 110kt, and the flap travel has also been increased by 3.5° to keep landing speeds low.
As is the case with most modern aeroplanes, the hardest part of getting checked out is learning how to operate all the avionics efficiently! Consequently, before going anywhere Charlie gave me a briefing on the systems, not just those fitted to the demo aircraft but all options.
Charlie flies A340s for Virgin Atlantic and has thousands of hours of glass cockpit experience, but even he freely admits it took him a while to become completely comfortable. Indeed, the systems are so sophisticated that Emirates have ordered SR22s as basic trainers, thus introducing cadets to ‘glass’ at the start of their training.
Interestingly, a philosophy that Airbus and Cirrus share is cockpit commonality, making it easy to go from the entry-level SR20 to a SR22T. And I bet the cockpit of the Cirrus Jet will be the same.
I’d say the G5’s avionics and pilot/aircraft interface have set an entirely new level for SEPs. The quantity of information available, the clarity of presentation and the amount of redundancy built into the avionics is nothing less than remarkable. Furthermore, the already impressive level of 3-D accuracy is enhanced by new WAAS technology, enabling fully coupled GPS approaches utilising lateral and vertical managed guidance.
As the Garmin GFC-700 autopilot is slaved to the Cirrus Perspective system and offers altitude pre-select, GPS steering and ILS glideslope coupling, as well as all the standard features of a modern autopilot, reducing the pilot’s workload greatly. With all this information displayed on the MFD’s big screen the pilot’s situational awareness is raised to levels that would have been impossible barely ten years ago. Forget automatics, this system is probably best described as automagics!
However, as good as it is there are still a couple of aspects about the panel that could stand improving. I know I always say this, but you can’t beat red ‘Master Warning’ and orange ‘Master Caution’ lights sited just above the Primary Flight Display (PFD) – the actual nature of the out-of-limits condition can then be displayed on the system’s MFD. To be fair, red warnings and amber cautions are displayed on the right side of the PFD, but there’s a lot going on in the screen, and I like my warnings to be big and obvious.
Secondly, the new Mid-Continent 4-in-1 digital standby instrument is not only too small but poorly sited. I’d move the P1’s air vent a bit higher, replace the key operated rotary mags/starter switch with guarded tumbler switches for the mags and a button for the starter beneath the PFD, then install an Aspen EFD 1000. After all, if we have a keyless entry system, why do we still need a key to start it?
The Cirrus is obviously a serious travelling aeroplane, so I decided to do the test in two parts. The air-to-air shoot would also enable me to examine the speed envelope, control and stability, and slow flight characteristics, while on the second flight I’ll use the aircraft for its primary purpose, – and actually go somewhere.
Time to start the engine. A six-cylinder motor will always run more smoothly than a four, and the IO-550 fitted to the G5 is no exception. Indeed, it’s super-smooth, although the fact it is attached to the airframe at six points (most aircraft only have four) may also have something to do with it.
Sywell is a pretty simple airfield to navigate around, but if it weren’t the electronic airfield diagram displayed on the MFD would still make it easy to follow the correct taxiway. The pre-takeoff checklist was displayed on the PFD and was extremely comprehensive. There were even reminders to consider weight & balance and density altitude, along with an admonition to check that you can complete the proposed flight safely.
At the start of the takeoff run, I needed a couple of dabs of right brake to track the centreline but the airspeed rose rapidly and the rudder soon came alive. The briefed Vr is eighty knots, and this was achieved quickly, using around 450 metres of the runway in the process. Flaps up at ninety then accelerate to 120, this was twenty knots faster than Vy, but significantly improved the forward view.
We soon overhauled the cameraship. The Cirrus isn’t the easiest aircraft to fly formation in (I miss not being able to control the prop) but it didn’t take long to slide in. After breaking off, I got on with assessing the stability and control. It has well harmonised controls and with the optional yaw damper engaged, all but the steepest of turns require practically no rudder at all.
The Electronic Stability Protection was always on, even when the autopilot was off, and initially I found it quite disconcerting to feel the aircraft resisting high rates of roll and steep angles of bank. However, chucking around a G5 isn’t what it’s about, so that wasn’t really a valid test. It’s an easy aircraft to trim and, once trimmed, flying is more a case of merely applying pressure to the side yoke, not actually moving it.
The field of view in the turn and every phase of the flight is perfectly acceptable. Unsurprisingly, speed stability is good. When trimmed for 140kt, a displacement of 20kt saw it return to the trimmed speed after only two long wavelength-low amplitude phugoids. Stability is clearly strongly positive longitudinally, positive directionally and just barely positive laterally. The ailerons are spring-loaded so if you deflect them on the ground, they return to neutral. This means during a turn you can set the bank, let go of the stick and the aeroplane maintains the bank angle, just like an Airbus.
Slow flight is benign, and the stall innocuous, while a great safety feature is that, due to the drooped leading edge, the ailerons work even though the wing is stalled. The stall strips and ‘cuffed wing’ really work. As with its predecessors, the G5 is a pleasant and easy machine to fly – but you do need to sit down with the POH, plug into a ground power unit, and spend some time learning to operate those automagics to really get the most out of it.
Examining the cruise is interesting. On the G3 you had to set the power lever for 2,500rpm, then lean the mixture out until the fuel flow was 17.5gph, which gave 85% power, irrespective of the altitude. With the G5, you simply set the power lever to 30.5in MP, then ease the mixture lever back until the fuel flow indicator is adjacent to a cyan line. Simple ? and we soon had a very respectable TAS of 180kt.
If we’d had the time and inclination to file for FL250, the max TAS is a claimed 213kt, not bad for an aeroplane with a fixed undercarriage. The maximum wing loading is quite high at 121kg/sq m, so as you’d imagine the ride quality is very good.
Along with all the usual engine indications (such as rpm, manifold pressure, oil pressure and temperature) the Perspective can display a huge amount of other engine information, such as fuel flow, CHT, EGT, power (as a percentage), volts, amps etc etc. Fuel management is easy, as a fuel flow totaliser computes both MPG and fuel remaining at each waypoint in the flight plan, including your destination.
Should you want to operate the engine at a more economical power setting, there is a ‘lean-assist’ function included in the system. Not only does this provide guidance for both ‘rich-of-peak’ and ‘lean-of-peak’ operations, but it has built-in advisories to automatically alert the pilot when the mixture is either too rich or too lean.
In an aircraft like the G5 there’s nothing like flying a reasonable, stabilised final ? and my approach back to Sywell was nothing like a reasonable, stabilised final. Nothing falls off, but it’s fair to say it wasn’t the best landing I’ve done.
Despite that, my afternoon with Charlie convinced me of something. I’d thought the G3 impressive, but the G5 is considerably better, being another evolutionary step for a well thought out and highly successful design. Could the G6 possible be better still?
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