AVweb

« Back to Full Story

Barefoot Flying

  • E-Mail this Article
  • View Printable Article
  • Text size:

    • A
    • A
    • A
This article originally appeared in Kitplanes, Dec. 2007.

New Aircraft

Launching from the softly rippling surface of Lake Seminole in St. Petersburg, Fla., felt slightly like what a stone must feel like after a youngster's sidearm sling sends it skipping across the water. There's a little bounce, a slight skip, then another. But, unlike the rock, the Corsario two-place skips skyward and climbs smartly away from the water instead of sinking into oblivion. As with others of its configuration, the Corsario shows traits that commend it to any pilot as much interested in flying from lakes, gulfs and bays as in frequenting runways on terra firma -- barefoot or shod. No Johnny-come-lately design, the Corsario is from Microleve in Rio de Janeiro. It first flew in 1982, and the number flying outside North America totals more than 600. Thanks to a complete kit, an attractive price and decent flying qualities, 10 U.S. buyers have hatched Corsarios in the two years since Sport Air's founder and owner Steve Cohen began importing the kits. What's more, Sport Air plans to offer both SLSA and ELSA versions late this year to supplement the experimental/amateur-built version.

An Amphib of a Different Nature

Corsario MK-5

Several items on the Corsair stand out as different from the some of the conventions found in other ultralight-rooted designs such as the Aventura II and Buccaneer. Like those, the Corsario employs a parasol wing ahead of a pusher powerplant over a boat hull with maingear that can be repositioned. Unlike its contemporaries, however, the Corsario uses tricycle gear. Instead of arcing straight up span-wise, the mains rotate in parallel with the fuselage sides until the wheels are about even with the top deck; the nosewheel retracts into a well in the nose. (Making the third wheel retractable while moving it from back to front adds a little complexity to transitioning from land plane to floatplane. More on this in a moment.) Despite its tricycle gear, though, the Corsario still sits on its tailskid when unoccupied, similar to many other pusher designs.

Hard Wing, Good to Find

Another variation from convention may not be as obvious as the gear: the "hard wing." The original Corsario of 1982 used a wing structure of tubular spars, compression ribs and a Dacron covering fitted with tubular ribs to provide the camber on top and the flat surface of the bottom. Today's Mark 5 variant still employs fore-and-aft tubular spars, but they are tied together with formed aluminum ribs, a fiberglass leading edge cuff and an overall covering of Stits aircraft fabric. Tail feathers and control surfaces get the same covering and finish. Anyone familiar with some of the old flying boats and Grumman amphibs may remember throttle levers descending from the overhead of the cockpit into the space between the seats. The Corsario also sports a lever between the seats and overhead, but this lever controls the flaps. Extending from the chrome-moly steel structure behind and between the cockpit seats is the long lever used to move the two mainwheels. Pull the motorcycle-like lever to unlock the handle, and the mainwheels swing aft and away from the waterline. At seat level are two pairs of levers between the seats. From aft-to-front, the first pair is a matched pair for applying the mechanical mainwheel brakes; forward of these is a relatively small pitch-trim lever next to a longer throttle lever. Normally, this would end the levers list, but no. There's an additional lever at the front of the console for moving the nosegear. Pull up on the lock and swing the handle aft to stow the gear. The Corsario also sports a window in the nosegear well so you can confirm its position. While unusual, the Corsario's package of controls works easily.

Comfortable Space

In addition to providing comfort for its occupants, the Corsario's wide cockpit also means the builder has ample panel space in which to install the desired avionics, if compact instruments are used.

Inside the cabin is a framework of chrome-moly steel tube that supports the hull, carries the flying loads and controls mechanics. The seats supported me well, and flying the Corsario was a comfortable experience. The 44-inch-wide cabin easily accommodated one 5-foot-8, 220-pound pilot and one 5-foot-9, 185-pound writer. The Corsario comes standard with clamshell doors large enough to make entry and exit easy -- even from a slippery dock. Lacking fresh-air vents, the Corsario was flown after owner Phil Klein removed both doors. Behind each seat resides a 10-gallon fuel tank; behind the tanks is a small luggage space accessible via a clear, top-hinged hatch. The wide cockpit also means a wide panel, more than 40 inches in the Corsario, which means plenty of space for all the equipment a light amphib needs. The dual sticks are comfortably located; the centered location of the controls makes access equal from either seat. Barefoot flying kept the experience tactile; neither shoes nor sandals would feel right in this environment.

All the Water's a Runway

The Corsario's hull design keeps splash and water drag to a minimum when the pilot employs a takeoff technique that gets it on the step quickly.

Klein was first to get a Corsario in the U.S., and N912PK is now approaching three years old. Before heading out to Lake Seminole, Klein uncovered his plane as I gave it a thorough preflight. The process is actually simple and straightforward, with hinges, wires and struts easy to see and touch. The linkages are equally easy to check, though pulling the dipstick on the Rotax 912 does require a ladder, as the hull aft of the engine is a no-step zone. Beyond the usual checks common to any aircraft, the Corsario requires one other step: checking and running an electric bilge pump that pulls water from the low point of the fuselage. Water can get in for many reasons in an amphibian of this style. The Corsario has extra sources, including the cables connecting the nosegear to the rudder pedals. On engine start, the Corsario wants to move on the water, even with only idle thrust, and a water rudder would be an asset for maneuvering, especially in tight spaces. While a little blast of power generates a swift response from the aircraft when you apply rudder, the power also accelerates the plane, and there are no water brakes. Once on the lake, taxiing the Corsario was easy to pick up; it responded smartly to the rudder and power, much like a small sailboat in a stiff breeze. Appropriate application of opposite ailerons kept the Corsario closer to level and prevented the outboard-mounted sponsons from adding their own drag to fight turning. Lined up into a gentle, westerly wind, the Corsario introduced me to its style of water launch, thanks to the coaching of Klein. The best drill requires full aft stick at the same time you move the throttle to full. Otherwise, the thrust line of the prop tends to send the Corsario's nose porpoising through the water, an uncomfortable ride that could damage the hull. With full aft-stick and full power, the Corsario quickly came up on the step. Easing off the aft-stick pressure rewarded me with a smooth departure from the water at less than 50 mph indicated and a climb of about 500 fpm at 65 mph IAS. Aileron response is excellent, and the stick pressures are reasonable and progressive. The steeper or more aggressive the turn, the higher the pressure required for the desired response -- as it should be. The Corsario held turns fairly well once established. Carving a perfectly coordinated turn, though, takes a little more than feet-on-the-floor flying. The Corsario's shallow dihedral is almost enough to generate the natural roll-yaw coupling of other aircraft, but not quite. Leading with the rudder is necessary to start and end with the slip/skid ball centered. Sampling some shallow, standard-rate and steep turns pointed up the need for the rudder in increasing doses. Despite near full deflections of the pedals, the response was not as quick or as positive as that of other, similar designs. Motoring along at a cruise setting of 5000 rpm, trimmed to 80 mph IAS at 600 msl, the Corsario wanted to hold heading and altitude fairly well, despite lumps, bumps and burbles in the air along the Gulf Coast. But many of those disturbances started the Corsario's tail wagging, which in turn caused the plane to start a shallow roll. Between the yawing tendency and the muted rudder response, it seems a larger tail, longer fuselage or a combination of the two could be helpful, things Cohen and Klein have discussed with the factory.

Them's the Breaks

Stalls illuminated an interesting conflict in responses between clean and dirty. Clean, the Corsario decelerated nicely, allowing me to keep the ball centered and hold altitude until just before the stall set in at about 40 mph indicated. This is in line with the published 42 mph, given our flying weight of around 1200 pounds and the usual inaccuracies of the pitot-static system. Just as the stall set in, the left wing slowly started to fall off, and at the break the nose followed, heading down, all very gently and easily corrected by easing off the stick and applying right rudder. Altitude loss was maybe 50 feet. With the two notches of flaps recommended for approach and landing, the airspeed needle wound to 34 mph. And then, with neither advance buffet nor hesitation, the airspeed needle plunged to zero, the right wing dropped swiftly toward the Gulf, the nose fell through and a right-rotating spin seemed imminent. This was the moment that let me know my lap belt could well be tighter. A swift push of the stick away from my lap and rapid application of left rudder and power brought the Corsario back to normal flying as if nothing unexpected had happened, albeit 100 feet lower and 90 degrees off my original heading. Klein seemed surprised, but noted he'd not stalled the airplane the same way. Importer Cohen's reaction, when told, was to note that the airplane has a good reputation, but if that's what it did, that's what it did. He did say that the drill with amphibs generally doesn't include full-stall landings. Nevertheless, this characteristic -- which might be improved with rigging changes and/or stall strips -- is something builders and transitioning pilots need to be aware of.

Splash Time

When sampling a plane for the first time, my preferred introduction has the demo pilot show me a maneuver before trying my own. See one, do one, learn one. Watching Klein take the Corsario back to a liquid surface affirmed my expectations that it would act much like other similar designs. First, when the water is your runway, concerns about the differences between nosewheel and tailwheel landings pretty much vanish. The surprise of my landings came in finding them easier to do and executed more slowly than expected. Setting up my first landing on Lake Seminole, I rolled the Corsario onto the downwind track at about 500 feet above water level. Easing back on the power brought a slow pitch-up moment that would have slowed the Corsario below my desired 60 mph approach speed but for my countering the pitch-up moment with nose-down pitch input. The little amphib tracked well through the aerial chop, descending at about 500 fpm through 300, 200, 100 feet. When the Corsario dropped low enough to feel ground effect, easing back off the stick and the low power setting rewarded me with a smooth, relaxed touchdown at about 50 indicated. After a little more than 100 feet or so, we were down to a fast-taxi speed. Instead of taxiing back I opted to take advantage of more than a mile of open water in front of me. Simultaneously adding full throttle and full aft stick brought the Corsario roaring ahead and off the water again in a little more than 100 feet. After a climbing right turn to 600 feet, I tried landing again, this time easing onto the water at just over 35 mph and stopping even sooner. Not only does it feel good to do this air-to-water stuff, it's downright fun.

Don't Forget Your PFD and Oars

With a couple of reservations -- particularly the full-flaps stall behavior -- the Corsario earns high marks for fun, for flying simplicity and for value. For value, about $42,000 gets the plane, complete with the 912S and three-blade prop, minus avionics. Other than finishing the panel and painting, there's little to make or buy to ready the Corsario for flight. In what is really more of an assembly process than a building process, a builder could have one finished in two weeks with, say, 100 hours or less. Stall practice should help a pilot avoid the rude surprise of the flaps-down experience I had. And practicing taxiing should help a pilot become accustomed to maneuvering around docks, other craft and in tight places on the water. Even if a water rudder isn't in the near-term future for the Corsario, dealing with the less-than-ample rudder and yawing tendency would take this design from a pretty decent machine to an excellent one ... we'll see if the factory responds to builder input. The future could be even brighter for the Corsario as an ELSA and SLSA, which Cohen expects to achieve by year's end. As a ready-to-fly product, the price will be about $60,000, Cohen says. With a finished, equipped weight of about 700 pounds, the Corsario offers plenty of payload even after taking on 117 pounds of fuel. With a great fun quotient and the flexibility nothing but an amphib can provide, the Corsario could take two on some fun adventures. For more information, visit the Sport Air Aviation Web site.

More articles about production aircraft are available in AVweb's New Aircraft Index. And for monthly articles about kit-built airplanes, subscribe to AVweb's sister publication, Kitplanes.

« Back to Full Story