|Text and Some Images By AVweb Special Projects Editor|
Seems like everybody wants to strap a larger engine onto a successful aircraft design and call it "improved." But when Cirrus Design was ready to develop a step-up model after its very successful SR20, they knew they wanted to do more than just add some horsepower. AVweb's Dave Higdon shows that, while you might mistake the SR22 for its predecessor on first sight, wait until you climb in!
General aviation boasts some fine fundamental designs that thrived partly thanks to the time-honored tradition of making an engine change to make a different airplane. Cessna's Skyhawk 172, to cite a popular example, is currently available in versions with 160 and 180 horsepower, the latter dubbed the SP. Piper's original PA-28 Cherokee proliferated thanks to versions with 150, 160, 180, and 235 horsepower. Similar examples exist at Beech, Commander, Maule, Mooney, and beyond.
And the practice continues today, albeit generally with a bit more marketing savvy applied in giving planes names like "Warrior," and "Archer," and "SP," instead of "Cherokee 160," or "Cherokee 180," or even "172" and "180." Today, it takes a newcomer some time to learn that the Piper Dakota is really only a refined version of the Cherokee 235, or that a Cessna Cutlass is little more than a Skyhawk with a 195-horse engine and retracts.
But once in a while, a different designation is warranted as much because of distinctive differences in flying quality as because of differences in powerplants.
Cirrus Design Corp. builds such a distinctive model in the SR22, on its face merely the original Cirrus 200-horse SR20 tricked up with 310 horsepower. Despite their shared airframe components, these two airplanes differ enough in traits and features to warrant consideration as two totally different birds. (The SR20 was reviewed previously on AVweb.)
That said, these two Cirrus designs provide ample DNA evidence of their common genes in noteworthy areas: the standard-equipment parachute systems, for example, as well as the roomy two-door cabin and side-mounted yoke controls.
In the best part of this story, the SR22 picks up where the SR20 max'd out, offering improved payload, stronger climb, higher cruise speed, and a style of panel-power redundancy rare on single-engine airplanes. Yessir, while instances abound of planemakers swapping out the powerplant of a fine machine to make more-powerful -- albeit mediocre -- version, that's not the case with the SR22. It can stand on its own.
You possess a better-than-average eye for details if you happen to pick up on the differences between Cirrus' maiden model and its newer sibling, because they share so much -- like sisters born close enough together to share wardrobes but far enough apart to hang with different crowds. Some examples: the SR20 and SR22 share fuselages, interiors, avionics, tails, and parachutes.
But from the start, Cirrus intended the SR22 to be its own bird, if you will. A growth model, yes. A super-SR20, no. Cirrus co-founder and President Alan Klapmeier insisted from the start that differences between the two would be as prominent as similarities. And he spoke the straight skinny.
Differences abound between the two -- again, aside from the obvious engine difference. The SR22 uses Teledyne Continental Motors' 310-horsepower IO-550, the SR20 the IO-360-ES making 200 horsepower.
Cirrus employed a few significant design changes in the SR22's wing -- one of those noticeable, another invisible, inside the wing. The visible change involves the addition of an 18-inch extension at each wing tip. The wider span (38'-4") provides more wing area, to better distribute the higher wing loading and improve initial climb and high-altitude performance.
The SR22 also picked up about 40 pounds of structural improvements in the main spar to better handle the aircraft's 3,400-pound gross weight. While we're still hanging around the wing, the higher weight of the big-bore Continental and three-blade Hartzell prop necessitated moving the wing about three inches.
But if larger wing tips and wing-fuselage interface points are a bit subtle for you where identification is concerned, when in doubt, cast a glance at the wing root. Cirrus engineers mounted a vortex generator (VG) on the fuselage just ahead of each wing root to keep air flow attached to the wing at higher angles of attack, which, in turn, improves low-speed handling. Because the VGs stop working just above stall speed, stalls still begin at the wing root and propagate normally toward the wing tips.
And there are other changes you might notice with the two planes parked side-by-side. For example, the SR22 boasts a taller landing gear set, raising the SR22 about three inches for greater ground clearance with the big 78-inch Hartzell prop. As an average-to-short pilot, I noticed the taller gear did change the view somewhat during taxiing, while assuring a slightly earlier arrival on the ground.
The SR22's dual 24-volt electrical system is another noteworthy change from the SR22. Primary and back-up electrical systems provide power redundancy to a panel devoid of air-powered gyro instruments -- neither vacuum pumps nor air-powered gyro instruments exist in the SR22.
Cirrus designed a primary and essential electrical system using two of everything: alternators, regulators, batteries, and electrical buses. Even if the unlikely should occur -- the ship loses its main alternator, main battery, and secondary alternator -- the second battery provides the essential bus with about 45 minutes of power. Hardwired to the essential bus are the electrical attitude indicator, HSI, turn coordinator, S-Tec System Fifty Five X autopilot, and the primary nav/com -- the highly capable GNS 430 from Garmin International. This arrangement provides the pilot with full IFR capability, including ILS, GPS, and VOR/LOC functions, attitude and heading indications, and a powerful autopilot.
Too few small aircraft possess redundant suction sources; fewer also boast of electrical-system redundancy. And for too many aircraft still, the loss of either electrical or vacuum sources puts the pilot in a partial-panel situation. Now this isn't an endorsement for over-extending one's capabilities in bad weather, but what an assuring level of redundancy for those times when most of what can go wrong has -- weather worsening, systems failing, and a challenging ATC environment. Not my idea of a good time to face a partial-panel approach, if a good time ever exists.
Between the engine, airframe, and system changes, the typically equipped SR22 on the ramp carries about 300 pounds more weight than the typical SR20, tipping the scales at 2,250 pounds. And the cabin is well-designed and comfortable, with plenty of legroom in back and 32 cubic feet of luggage space with a 130-pound capacity.
With a gross weight of 3,400 pounds, the SR22 boasts a full-fuel payload of about 646 pounds. That's couple of adults, a couple of children, bags, and the full 84 gallons of fuel (with 81 useable). No one should feel squeezed, crowded, or claustrophobic on a nominal 500-nautical-mile flight. The trip won't quite take three hours.
That's because the SR22 is particularly strong at converting minutes into miles.
As closely matched as the SR20 and SR22 are in many areas, they differ most in speed, range, and fuel efficiency. At a true cruise speed just over 180 knots, the SR22 covers about 750 nautical miles in about 3.8 hours -- with reserves on its 84 gallons. That's about 50 miles shorter than the SR20 goes on 60 gallons cruising 160 knots for about 4.25 hours.
Cirrus Design Corp. SR22
Maximum Gross Weight: 3,400 lbs
Standard Empty Weight: 2,250 lbs
Maximum Useful Load: 1,150 lbs
Payload w/full fuel: 646 lbs
Fuel: 84 gallons
Oil: 8 quarts
Engine: Teledyne Continental Motors IO-550-N, 310 hp @ 2,700 rpm
Propeller: Hartzell three-blade constant-speed, 78-inch diameter
Wing Span: 38.5 ft (11.73 m)
Wing area: 144.5 ft (13.46 m)
Length: 26.0 ft (7.92 m)
Height: 9.2 ft (2.80 m)
Cabin length: 130 inches (3.30 m)
Cabin width: 49.25 inches (1.251 m)
Cabin Height: 50.0 inches (1.27 m)
Luggage compartment: 32 cubic feet
Luggage weight limit: 130 lbs
(ISA, sea level, gross weight, no wind)
Take-off ground roll: 1,100 ft
Take-off (to clear 50-ft obstacle): 1,600 ft
Maximum climb rate: 1,400 fpm
Landing (over 50-ft obstacle): 2,300 ft
Landing ground roll: 1,020 ft
Maximum cruise speed: 181 KTAS
Maximum range (plus IFR reserves): 1,000 nm
Minimum stall speed: 59 Knots
Airframe limitations: +3.8 Gs, -1.9 Gs
Service Ceiling: 17,000 msl
Vne: 204 KCAS
First flaps: 119 KIAS
Full flaps: 104 KIAS
Maximum maneuvering speed: 142 KIAS
Maximum demonstrated parachute deployment speed: 133 KIAS
Source: Cirrus Design Corp.
The SR20 consumes fuel at just over 11 gallons an hour at cruise, giving the 200-horse airplane a fuel efficiency of about 14.2 nautical miles per gallon at 160 knots. The SR22 uses about 16.7 gallons an hour but gets about 181 knots in return at 8,000 msl -- for a rate of about 10.5 nautical miles per gallon. At least, that's according to the latest from Cirrus' SR22 POH.
Interestingly, the SR20 can fly with about 614 pounds of payload carrying a full 60.5 gallons of fuel (56 useable). Thanks to its fuel efficiency -- about 11 gph -- eschewing about three gallons of fuel lets the SR20 pilot pretty much match the SR22's full-fuel payload and even range, but not the distance covered in an equal time frame.
And there are ways to stretch the range of the SR22, as there is with every airplane -- you basically sacrifice some of that speed for a lower power setting that yields a sufficiently higher fuel efficiency. As in, take the SR22 to 12,000 msl and above, live with 55 percent power, and get about 900 nautical miles at almost 170 knots -- still very respectable. And if you can tolerate the idea of 16,000 or 17,000 msl, the SR22 improves on its efficiency to give you more than 175 knots while covering more than 930 nautical miles.
Think for a minute about the efficiency of an airframe that can deliver 95 percent of its best-cruise capability on barely 55 percent power -- and the efficiency of a non-turbocharged engine that can still pull with more than 50-percent power just short of the official start of the Flight Levels.
And we're still talking legs under 4.5 hours. More so than with most airplanes, the SR22 turns out to be its most-efficient the nearer you get to its service ceiling.
As mentioned earlier, Cirrus' deep thinkers wanted the SR22's improvements to run deeper than from firewall-forward. And you've seen examples of how the evolved Cirrus compares to its elder sibling, examples which prove beyond a reasonable doubt that parents always treat the second child differently. We've talked about the changes in powerplant, in airframe, and in systems.
Fortunately, the two planes are fundamentally the same to fly and operate, aside from their fundamental differences. Sharing the same fuselage, cabin, landing-gear configuration, panel, and power-management hardware forms an unshakable common denominator. And that's pretty much a good thing.
Fundamentally, both Cirrus' share in interior configuration that mirrors the ergonomic cockpit-like interiors of modern luxury sports sedans, though the SR22's standard interior finish is more deluxe than the standard SR20 and more equivalent to the SR20's upgrade package. The two airplanes also share in panel configuration and available avionics, with both planes equipped with a large eight-by-ten flight-situation display (FSD); the new standard configuration uses a new screen from Avidyne after using Arnav displays in earlier aircraft.
In a sport-car-like center console directly below the FSD, Cirrus stacked the avionics in favor of the PIC, installing S-Tec's all-up 55X autopilot, and an all-Garmin stack: GTX 327 transponder, audio panel, and two muscular GNS 430 all-in-ones. Available equipment tucked away in back includes BFGoodrich's Wx-500 sensor, able to display its findings on either the FSD or one of the Garmins. Skywatch traffic alert gear is available, as is Sandel's 8803 electronic HSI/RMI/MFD.
The combination is all-encompassing in its IFR capabilities, thanks to the ability to substitute GPS guidance for DME and ADF-based approaches in most instances. Add Garmin's upcoming data-link receiver and the data-link service to get weather and traffic images, and you have some solidly capable weather- and traffic-avoidance gear -- even without the Wx-500.
Valuable though all this gear may be -- capable of flying the airplane to cruise altitude and back through an approach on its navigation and flight-control gear -- this highly capable airplane still requires a body and a brain, if for nothing more than to start the airplane and get it to and off the runway. And systems fail, making the appeal of a patently pilot-friendly airplane a major marketing asset.
In fact, the SR22 flies so nicely, so much like the SR20, that many of the SR-something pilots I've met spoke of the joy of turning off the S-Tec and maneuvering by hand for hours-long cross-country flights. The comments reinforce my feelings of comfort and ease in the SR22 -- balanced by a noticeable increase in stability at the high end of the airspeed indicator.
And like the SR20, the SR22 preps for flight easily and quickly, with pre-flight taking no more time than any other simple airplane. You check all usual suspects -- fuel, oil, wheels, tires, brake lines, control surfaces, lights, antennae -- and you've pretty much run the lineup. Making the step up might have been tougher but Cirrus decision-makers opted for a pair of steps -- fixed, like the landing gear -- mounted to the fuselage just aft of each wing.
Color-coordinated -- as in, white -- non-skid walkways provide the traction needed to make the transition from step-up to strap-in on a wing that advertises its slippery nature with the intensity of its gloss everywhere else. One step down to the floor, lower yourself to your seat, strap in, and start the checklist. Time to go flying.
There may be a problem for new pilots who earn a license in a Cirrus airplane and come to the time when they have to fly something else. After scores of hours in the logical, elegant layout of an SR22 (or SR20), the logic of some older airplanes' cockpits may seem to defy imagination. Cirrus designers placed virtually everything you need to touch within reach of the left seat -- starting with the main switch panel conveniently located on a horizontal surface on the bottom of the panel directly ahead of the pilot. Cirrus opted for wide rocker switches, labeled for easy reading, to control the master, avionics, back-up electrical system, and fuel boost-pump. Near the right side of this surface sit the dimmers for the interior lights.
Starting the big-bore Continental follows a common pattern. With the mixture at idle cut-off, engage the fuel boost-pump switch to its primer setting and watch for fuel flow, then stop the prime function. Turn the key, and when the engine hits, bring the mixture lever to full rich and pull power to idle. You're up and running.
Close the avionics master switch and up come the huge center-panel multifunction display, the Garmin hardware, and the S-Tec; you now get to watch a series of equipment self-test cycles run themselves while you wait for the engine oil to warm into the green. Once the big display finishes cycling up, you can run through the integral checklist items available. You can also program your flight into one of the Garmin GNS430s and finish the pre-departure checks.
Flying from Plant City Airport the day after EAA Sun 'n Fun ended, the temporary tower that existed the day before was no longer a factor. Accompanied by Cirrus' chief test pilot, Gary Black, it was almost time to taxi the SR22 to the runway for our final preparations.
For all its innovation, operating the SR22 is not that different than most planes, from start to shut-down.
Taxiing is one area, however, where Cirrus airplanes depart from the norm. Instead of direct-control nose-wheel steering, Cirrus uses a simple castering nose gear and differential breaking. In ground operations, the SR22 responds about as easily and quickly as the SR20, which surprised me considering the higher weight of the IO-550 up front. Once we reach about 20 knots, the rudder became effective enough to reduce my need for tapping a brake to change direction, which did make it tough to taxi slowly .
Another slight departure from the norm is in the engine-management hardware of Cirrus airplanes: A single lever to control throttle and prop, plus a mixture control. Although I'm not completely sure how it works, for the pilot the difference comes out like this: you don't have to worry about the propeller governor control. As you move the throttle from idle to full power, the linkage sequences the governor to full rpm, then back to a pre-set level as you retard the throttle lever that allows the prop speed to drop and manifold pressure to remain high. Pull the lever back more, and the manifold pressure starts to drop, then engine speed again, and finally, you're back off the governor altogether.
It takes a bit of patience to grasp what's going on, but no effort to manage: you set the power you want on one control. Set it and forget it.
Finally, Cirrus airplanes employ a side-mounted yoke -- not a side stick or center yoke, a side-mounted yoke. We've been here before on the SR20 and both the Lancair models. The entire hand grip rotates around the axis of a control column for roll control and the column moves forward and aft for pitch -- like a conventional yoke with only a single handle and moving in and out of the panel at the outboard edges.
The impact of the side-mounted yokes on the panel is as awesome in the Cirruses as it is in the Lancairs: acres of free, unfettered, uncrowded instrument panel directly in front of you.
And then there's the final checklist item you deal with before releasing the brake to taxi, one safety system that makes Cirrus airplanes truly singular: the Cirrus Airframe Parachute System, or CAPS.
Ballistic Recovery Systems Inc. (BRS) of South St. Paul, Minn., designed, tested, and certified the CAPS system, and helped Cirrus certify the system in the SR20 and SR22. CAPS employs a small rocket motor to break through a thin fuselage membrane and drag the parachute out of its container, a standard sequence developed and employed over BRS's years of experience in emergency parachute systems for aircraft.
In reality, your only acts in managing this unique piece of equipment involve arming it and using it.
To arm, you open an overhead cover and remove the red-flagged safety pin from the deployment handle. To use, you open that same cover and pull the handle.
The sequence lasts about 1.5 seconds from pulling the handle to full-line stretch; a full canopy follows in another couple of seconds, making the total process extremely fast. And when deployed, the canopy lowers the aircraft at about 1,700 feet per minute. Upon impact at that speed, the landing gear deform first, followed by the controlled crushing of the seats, as designed. The total residual impact force should let passengers walk away -- sore, bruised but otherwise unbroken.
The deployment saves the occupants but not the airplane, which will be considered totaled by the insurance carrier. Although more than 100 documented saves have been recorded by BRS systems on ultralights, experimental aircraft, and hang gliders, as of this writing, there have been no Cirrus CAPS deployments to report. If you're anywhere in or around aviation when that finally happens, you'll hear.
With the parachute armed, the engine run-up accomplished, our departure time is here. I use the coolie hat atop the side yoke to set a bit of nose-up trim, center the aileron trim, and check that the separate rudder trim is also neutral.
Lined up on Plant City's Runway 27, we turned up the wick: advancing the single power lever to full brings the big Continental up to a roar at its 2,700 rpm redline, and in an instant, SR22 N703CD begins to accelerate along the runway.
It takes but 13 seconds before the airspeed indicator passes 70, where the SR22 lifts off the runway smoothly and easily, accelerating toward 100 knots as we climb -- despite the humid 85 degrees of this warm Florida evening. The VSI swings confidently past the 1,500 feet-per-minute mark, and before we cross the departure end of the runway, it's time to pull the power lever back to a detent and let engine rpm drop to a quieter, less-thirsty 2,500 rpm.
It takes a bit of down trim to pitch the nose for a 120-knot cruise climb, where the VSI drops back to 1,000 fpm as the nose simultaneously falls to improve my view ahead. For me, the best attitude and climb is one with the best view ahead, given that the Tampa Class B sits but a few miles west, while post-Sun 'n Fun traffic continues to stream out of Lakeland immediately to the east.
And the best direction for my work is south, so with a gentle rolling motion on the side yoke, the SR22 carves an easy standard-rate turn as commanded, with virtually no rudder input needed while the climb continues. The big Continental churned away, taking us to 7,500 msl in about seven minutes while never losing the potential for four-figure climb rates.
That evening, extrapolating the day's conditions to what's more typical for summer in the western U.S., the number showed that that the SR22 should still climb at rates in the high three-figure range all the way up into the middle teens. As usual, horsepower proves a significant asset for flying out of high-field-elevation airports like those found in Arizona, Colorado, Idaho, West Kansas, Montana, New Mexico, and Wyoming.
Pulling the power level back to the next detent gave me a power setting of about 2,400 rpm and 23 inches of manifold pressure -- about 75-percent power. Leaning down toward 18 gph brought true airspeed up to 183 knots; leaning past peak dropped fuel consumption into the 16 gph range, while true airspeed declined to just above 170. As with most airplanes, lower fuel flows help extend the range of the SR22. But the higher fuel flow better assures the engine cooling necessary to get the engine to its 1,700-hour TBO.
Regardless of how hard you work it, managing the engine in any Cirrus is 33-percent easier and simpler than other constant-speed-prop aircraft; the single-lever control for power and rpm makes managing the Cirrus' power comparable to managing an aircraft with a fixed-pitch prop. Only the mixture control remains to manage between climb, cruise, and descent. And the EGT and fuel-flow instruments simplify the process.
Once you establish your trim, turn over the flying chores to the S-Tec, and lean for the desired fuel flow, you don't want to reverse the process. But at some point, we must all come down. And slowing the SR22 requires more in the way of advance planning and aircraft familiarity than most iron in this class -- a product of its clean, sleek, non-iron aerodynamic efficiency.
This is, after all, an airplane that cruises easily with the fastest of its 300-horsepower class -- and better than many 300-horse birds -- with its wheels welded in the down position. Perhaps the somewhat-low flap-deployment speed exacerbates the sensation of time; it's no quick matter to go from 160 knots indicated down to the 119 knots indicated where you can use the first 16 degrees of flap. This is an area where practice will improve the process, and slow-learner pilots should plan on logging some added hours to assure that their descents work out as needed.
Conversely, once slowed, the SR22 engages no need for special caution or concern about maintaining control, even in the briskest cross winds. Carrying over one of the SR20's strongest traits, the SR22 can be handled with aplomb, regardless of which end of the envelope you're flying. Take high-speed cruising, for example. With trim controls for all three axes, you can dial the SR22 in to level flight over a broad range of flight conditions. Once trimmed, the SR22 resists diverging from that attitude -- without the touch of the S-Tec.
S-Tec's System 55X provides pretty much the full boat in autopilot capabilities, allowing you to track a heading, a VOR radial, and a GPS course, as well as to manage your climb and descent, and hold altitude in between. And when the muck is down to minimums, the S-Tec becomes a great second-in-command, by handling the airplane through coupled approaches if you so desire.
One problem no pilot should encounter in the SR22 is an inadvertent stall while maneuvering at the low end of the envelope. The SR22 makes you work for a fully developed stall, clean or with full flaps. The technique that seems to work best for me involves progressively pulling power while trimming to hold altitude until the engine speed drops to idle. Even with the trim full aft, the SR22 still demanded additional back pressure on the side yoke before even entering buffet territory.
By the time the stall horn sounded, my arm was wearying from working to hold up the whole front end of the airplane. Finally, well into the stall horn sounding, the SR22 started a series of pitch oscillations when the nose fell through at about 53 knots indicated, settled into a mush that accelerated to about 750 fpm, and started the nose rising again to a descent rate of about 550 fpm.
Best of all, holding the stall for about 20 seconds never deprived me of aileron or rudder control. As the nose bobbed and dove, the wings remained level with my aileron input while the rudder helped me hold my heading control. All in all, very confidence-inspiring, considering that the brisk winds gusted at 30 degrees to 40 degrees off the centerline of Plant City's Runway 27.
Naturally, that would be the case when the time came to come down, where the SR22 challenged me most -- landings. During a series of touch-and-goes, I found myself starting to flare a bit too high on one pass, a bit too low on the next. Check off any gear concerns after those two "arrivals."
But the SR22's solid feedback and tactile response helped me dial in to the proper technique and timing just in time for my last try. And on touchdown each time, the rudder alone was more than ample for holding the SR22 straight on the runway centerline.
It seemed at the time that the high nose-up attitude at stall and the SR22's taller gear contributed to my bobbled arrivals; the cross wind also helped me retain my humility. Differential braking, once my speed dropped below 20, helped me retain directional control over the airplane.
Unreservedly, Cirrus's SR22 adds another solid contender to the market for high-performance singles, albeit one more capable than other more-sophisticated competitors. For any serious general aviation pilot, the strengths of the SR22 will be hard to ignore -- especially for the money. In fact, this power class has only one other aircraft that comes close, Lancair's muscular Columbia 300, another composite. In fact, they share an engine.
While the Columbia may be a few knots faster, it lacks the CAPS system and costs a bit more -- about 12 percent more. Cessna's highly capable six-place 206 Stationair can't touch the SR22's speed, although it both carries more and costs more. And Raytheon's venerable Beech A36 Bonanza, a six-seater, and Commander's four-place 114, cost far more -- about double, in the Bonanza's case -- while giving up more than 20 knots to the SR22. Mooney's 280-horse Ovation 2 and 234-horse Eagle 2 come closest in cost and capability, but like the Bonanza and Commander, they both bring the added maintenance burden of retractable landing gear.
Measured against all these other high-performance models, the SR22 sits at the bottom of its class in price and near the top in performance, sophistication, and user-friendliness. Cirrus airplanes, however, stand alone in their unique safety feature, the BRS/CAPS system.
You can spend more money on more history, more birds of a feather, and get no more -- probably even less -- in efficiency and capability.
Once disregarded as a pipe-dream airplane, the SR20 now has company to help spread the Cirrus philosophy of more speed, more features, and more safety, for less power, and less money. If the SR20 has proven a threat in the 200-horsepower class, the SR22 is twice that threat to the high-power planes in its horsepower class, and some lower-powered, lower-capability airplanes in its price range.
About the author...
Dave Higdon has a distinguished background in aviation journalism. As aviation editor for The Wichita Eagle for more than five years, he has established a reputation as one of the best general aviation reporters in the business. Previously, Dave held a variety of aviation journalism assignments with The Journal of Commerce, Air Transport World, and AOPA. He has covered every facet of aviation, from sport aviation in Tennessee, to the FAA in Washington, D.C., to Cessna, Beech, Boeing, and Learjet in Kansas. He's also a professional aviation photographer. Dave is an instrument-rated private pilot and owns a very clean Piper Comanche. He and his wife Annie live in Wichita, Kansas.