Posted by: Glasair | November 2, 2009

“The Sportsman 2+2 may well be the best all round plane in the NTCA market. It is quite simply one of the most appealing and capable personal aircraft I have flown.”

SA FLYER MAGAZINE

FUN FOR FOUR

Tuesday, 21 July 2009

Fun 4 Four

The Sportsman 2+2 may well be the best all round plane in the NTCA market. It is quite simply one of the most appealing and capable personal aircraft I have flown. NTCAs or Non Type Certified Aircraft are where most of the innovation and development is currently taking place. Without the huge costs of the formal certification process, the NTCA market also now delivers factory-built planes that are excellent value for money.

Increasingly, many NTCA manufacturers are now offering complete aircraft – i.e. factory built – to buyers outside the United States. Being outside the US means they are not constrained by the 51% rule which requires more than half the aircraft to have been built by the owner.

The NTCA market has come to be dominated by giants such as the RV series and locally, the Jabirus. But in almost every respect, as an all round package, it is better than these competitors. The Sportsman 2+2 is faster, slower, bigger, cheaper and more versatile than anything else out there that you can buy off the shelf, with the comfort of knowing that it has been professionally built.

DEVELOPMENT

All thoroughbreds have a lineage – and the Sportsman’s is particularly interesting.

The Sportsman 2+2 can be traced back to 1979, to Tom Hamilton’s sleek low-wing Glasair.  Then in 1994 Hamilton changed direction and created a high-wing two-seater called the GlaStar. Not only did it look completely different, compared to the all composite Glasair, the GlaStar and its successor the Sportsman use different construction techniques and materials throughout the airframe, in order to use the best construction technique for that particular application.  Thus, the fuselage is a welded tubular steel cage covered by a non-structural composite shell, the wings are externally braced stressed skin aluminium, the aft body of the fuselage and vertical fin is structural composite, and the horizontal tail section is aluminium.

The idea was that welded steel tube is a superior material for building large, strong, and lightweight structures with predictable strength and failure characteristics; composites are ideal for building the curvaceous aerodynamic shell, and aluminium is used in the wing for its great strength-to-weight ratio.

Despite their similar outward appearance and innovative blend of construction types, the Sportsman shares only 30 percent of the parts with the GlaStar. The two aeroplanes share the same tail plane, elevator, rudder, ailerons, and other control system hardware. However, the wings, flaps, lift struts, fuselage structure, fuselage composite shells and landing gear have been altered to handle a 340-lb increase in gross weight, to 2,300 lbs.

The fuselage is 12 inches longer and much larger in the aft section than the GlaStar. This made it possible to add rear seats. The company describes the Sportsman as a 2+2, which means the rear seats are really useful only for children. However, without the seat, the Sportsman has a cavernous baggage compartment capable of swallowing up to 300 lbs. At American airshows they usually stuff all their camping gear, including bicycles and tents, into the baggage bay.

The Sportsman’s high aspect ratio wing is similar to the GlaStar’s, but the Sportsman benefits from redesigned flaps with increased chord and a new hinge location that permits a higher flap limitation speed. With take-off flap the Sportsman’s tracked flaps increase the chord and expand the wing area by three square feet with a minimum drag penalty. Another refinement is the addition of a servo tab on the left aileron, which reduces roll forces, particularly at high speeds.

Like the GlaStar, the Sportsman features folding wings. If the horizontal stabiliser is removed, the entire aeroplane can be folded and loaded on a trailer within an hour and so stored at home in a single-car garage, which is great for saving on expensive hangar space. An unusual item in the pre-take-off vital actions is verifying that the wing pins are securely in place. Two annunciator lights will however alert you if the wing or horizontal tail pins are not secured.

In the United States most Sportsmans are sold as kits and builders tailor-make their aircraft to personal preferences— one of the major benefits of building your own. The factory also offers and innovative two weeks to taxi build program. This involves the buyer in the build process and delivers the aircraft to him with less than two weeks work left to get it to a complete enough condition to taxi.

As a kit, the Sportsman offers a remarkable number of options direct from the factory. For example, all the appropriate aircraft structure is in place for either a tail-wheel and tricycle undercarriage. You don’t even have to make a permanent selection; it is convertible from one configuration to the other within a claimed two hours. Choice is good but for me, the undercarriage configuration option is much like that of the folding wing option—cool, but I don’t think I would use it often. What these options do however, is increase the value of the plane. When it comes time to sell, the ability to convert from a taildragger to a nosedragger makes the market much larger.

ON THE GROUND

The pre-flight of the Sportsman has nothing unusual. Unlike Cessnas, the strut is behind the door and there is no step so getting in is a first glance awkward. However, if you know where to hold on, it’s easy to slide your legs in either side of the stick.

Once in, there is ample head, shoulder, and leg room, even with two large adults. The cabin is a generous 48 inches wide so there is plenty of space to move about. The seats are comfortable leather and the side panels and doors have a excellent finish that belies the kit sourced nature of the aeroplane. The door handles are hefty and beautifully made in brushed aluminium and give a reassuring affirmation to the overall design and build quality.

The instrument panel is in a practical grey metal with a box structure along the bottom for the power controls. The Sportsman has a four-tank fuel system with a combined capacity of 50 gallons. Fuel is either On or Off to the engine, with the selection valve mounted in the centre console forward of the flap handle. The selector has a prominent locking pin so fuel management must be deliberate, rather than a casual flick of a selector. The fuel gauges in the electronic PFD show the quantity in the inboard tanks only. The procedure is to burn off the inboard tanks for a couple of hours then transfer fuel from the outboards. Each outboard tank has a self-priming electric transfer pump. An annunciator light shows if a pump is in operation; if the tank is empty, the light turns amber and the pump automatically shuts off.

A gripe of mine is that many light aircraft have instrument panels that are two high. This is not the case in the Sportsman. The field of view is exceptional for a high wing aircraft. The only distraction is the two structural tube braces that diagonally cross the windscreen. However, once airborne I found that I stopped noticing these braces. Large overhead skylights add light to the cabin and improve your chances of seeing any traffic you may be turning towards.

The nose wheel is free-castering, so directional control is by differential braking. This has the advantage of being simple and enables the aeroplane to easily pivot round on one wheel.

Our test aircraft ZS-FBB uses the almost bullet-proof Superior XP-IO360 180 horse Lycoming. Engine operation is standard Lycoming fuel-injected IO-360. Our test flight and photo shoot was on a very cold Highveld winter’s morning and even after a long taxi, we had to wait for the oil temperature to move from red to yellow on the Advanced Flight System EFIS glass instrumentation.

IN FLIGHT

Normal take-offs are performed with one notch of flaps (15 degrees). Placo CEO Jeff Earle handled the take-off from Rand’s Runway 28. Even though there was plenty of runway, he ran the engine up against the brakes. Acceleration is brisk and we flew off at 50 knots, climbed at 65 then accelerated to 85 knots. Even with two large adults and full main tanks our rate of climb out of Rand was a healthy 700 fpm. We were about 180 pounds below gross and it was a chilly 5 degree Celsius morning, but even on a hot day the climb provided by the 180 horses would still be good. For those who want more for short hot and high airstrips, a 210 hp engine option is also available.

After a moment of searching the empty sky we spotted Carl Dollenberg, who was flying ZS-FPI as the camera ship. Jeff Earle teaches formation flying so it was a pleasure watching a master at work. He effortlessly caught the Cessna 182 up and then slowed down in perfect position for Willem Grobbelaar – who was happy for the opportunity to once again do air to air photography, despite having left SA Flyer a few month’s ago.

With the photos done, I took control and was immediately impressed by how well balanced stick forces were. The rudder is however powerful, as is necessary for tail dragger and float plane ops, so I found myself initially overdoing it a bit. But then those little electric ball displays are more sensitive than the seat of my pants.

I pulled the power back and somewhat clumsily yanked the flap lever for first stage flap. Jeff admonished me that we were still above the white speed arc, which was limited to 90 knots. When we were comfortably below the limit I applied the rest of the flaps and held the nose up. The coolie hat electric trim switch on the top of the control stick is a sophisticated touch for an otherwise simple aircraft. The stall came at 43 knots and was a complete non-event, with no wing drop. There is no aural stall warning system, but the Sportsman has classic stall manners and it should catch you unawares.

The beauty of the Sportsman’s docile high aspect ratio wing can’t be overstated. In slow flight, the Sportsman is stable and responsive. I retracted the flaps and tried a clean stall. The break came at 52 knots and was more pronounced. The left wing dropped, but not sharply. By releasing back pressure on the stick I was able to recover with just a 200 ft height loss.  I thought it inconclusive, so I asked Jeff to try. This time the right wing dropped. He pointed out that the powerful rudder needs to be used accurately to keep the ball centred to get a consistent wing drop.

A steep turn with a roll reversal showed exemplary manners and the braces across the windscreen made it easy to align with the horizon. Stick forces remained pleasantly light but not overly sensitive. The windows in the roof greatly ameliorated the usual high wing problem of not being able to see into turns.

With the handling review complete, I set it up for a low cruise at 22 inches and 2300 RPM and saw 111 knots on the GPS going southwards and 114 northwards. (It was an almost windless morning). Jeff said that at a more normal cruise of 2500 RPM and 24 inches, the Sportsman comfortably achieves book figures of 130 knots.

Heading back to Rand we passed overhead Panorama Airfield. “How about a short field landing”? I suggested.

Jeff needed no second invitation. We joined downwind and then flew at steady approach to Runway 02 at 55 knots, with a touch of power to clear the tall gum trees. Once we had cleared the trees, Jeff cut the power and we were down and stopped comfortably within 200 metres of the threshold.

The specifications show that at gross weight the Sportsman’s wing loading is, at 17.5 lbs./sq. ft,  a bit more than you night expect. It is thus possible to get the Sportsman well behind the power curve and establish a steep descent on final approach.  This is great for dropping in over obstacles or making spot landings, as long as you remember to arrest the descent with power, and not by pulling back, which the manufacturers say, will further increase the rate of descent. One wonders if, in the interests of a docile stall, the designers have limited the up-elevator authority.

Without backtracking, we applied power and were off the ground at 50 knots after a roll of less than 200 metres. To keep well clear of the approach to 03L at OR Tambo, the approach to Rand was flown with a tight circuit and steep final approach to Runway 28. Even though it was downhill, we had to let it roll out to reach the taxiway at the runway intersection. Before shutting down, Jeff demonstrated neatly the nimbleness of the castering nosewheel by pivoting the Sportsman on one wheel through 360 degrees.

CONCLUSION

The Sportsman is one of those rare aeroplanes that does everything well. The design compromises so evident in many aircraft seem largely absent in the sportsman. (In this respect it’s a bit like a Cessna 182!). It offers a combination of payload, performance, and exceptional flying qualities that is unmatched by certified or experimental aeroplanes in its class. Its flight envelope is impressive and its slow-speed handling is outstanding.

The few criticisms I have are mostly limited to personal preferences. With its steel tube structure and fibreglass cladding I found it a bit like being inside a drum, so good headsets are recommended.

As the Sportsman is type approved but not certified, all this capability comes at a very good price. Placo is selling ZS-FBB for just R1.6m plus VAT, which for a new aircraft, makes it excellent value for money.


Responses

  1. Your blogs are admirable and full of knowledge. Thanks for giving us such kind of matter to study.


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