Flight Design—Right Design

By Rob Neil.

What do highly qualified and extremely experienced senior airline pilots do with themselves when they “retire” and stop flying airliners? They go flying, of course.

Until recently, Ruud (Rudi) van der Zwaal and Tim Harrison of Sports Aircraft New Zealand spent their respective careers flying progressively bigger and bigger aircraft. Rudi began his career in the Royal Netherlands Air Force where he flew—among many other interesting aircraft—the Lockheed F-104 Starfighter. In a subsequent fascinating airline career, he flew a diverse range of airliners, including every model of the Boeing 747. Incidentally (he doesn’t advertise the fact), Rudi is actually a Dutch knight—“Sir” Ruud van der Zwaal. His Netherlands’ knighthood is the result of his volunteering in 1974 to ferry a group of terrorists around in a Boeing 707 as part of a deal negotiated successfully by the Dutch government to free hostages taken at the French embassy in The Hague. Rudi retired from Singapore Airlines only recently, where his last mount was the Airbus A340.

Tim Harrison’s all-civilian flying career began in the UK when he gained a PPL at 17 years of age. Then, after gaining his commercial licence, a brief stint in East Africa flying Twin Comanches and Aztecs preceded a 35-year career with British Airways until his “retirement” in 2005, when he moved to New Zealand. During his airline career, Tim flew Viscounts, BAC111s, and Boeing 737s, 757, 767s and, for the last eight years of his service, 777s. Throughout his career, he retained a keen interest in general aviation, owning a succession of gliders and building a Europa experimental aircraft.

It would be fair to say that with more than 80 years combined flying experience between them, these two men probably have a pretty good idea about aircraft and aviation.

It would be equally fair to say that, having investigated the world of modern light sport aircraft (LSA) thoroughly, when they decided upon the Flight Design range of aircraft as the one that they would most like to import and sell in New Zealand, they had very good reasons for doing so. Rudi and Tim have since imported two CTLSs (ZK-FDA and FDB) and they invited Pacific Wings to their Springhill base north of Auckland to have a look at the aircraft.

Flight Design

Flight Design’s founder began building hang gliders in the early 1980s. He formed the current company in 1988 and began building light sport aircraft. In 1997, Flight Design began building a light sport aircraft known as the CT. Since then, it has delivered more than 1,000 of these all-composite aircraft to customers around the world.

As incredibly popular as it remains (it is still the best selling LSA in the US and Europe), the CT might not be voted as the “most attractive” LSA in the world. One commentator rather unkindly described the CT as “an egg with tailfeathers”. However, its slightly “rotund” cabin and “egg-like” appearance are unavoidable by-products of the features that have been largely responsible for the aircraft’s outstanding success. The interior of the CT’s cabin is very large, ergonomically excellent and extremely comfortable. It is the view of and from the interior that pilots are mostly concerned with, and the thousand-plus sales of CTs around the world suggest that Flight Design got this all-important aspect exactly right.

The CTLS is 14 inches longer overall than the original CT and includes an additional window aft of the door pillar. Its additional length (added to the tailboom aft of the wing) makes quite a difference to the CT’s appearance and although it is still distinctively a “CT” at heart, the CTLS appears noticeably longer and sleeker, and slightly less “dinky” than its predecessor.

To this writer, the CTLS is far from unattractive. Its composite structure allows the airframe’s features to blend seamlessly from the “button nose” of its brilliantly pilot-friendly huge cabin to its delicate looking swept tail. The lack of bracing struts for the flawlessly smooth wings add to an overall impression of sculpted purpose.

Arguably, while the CTLS might not be “beautiful” to some, in this writer’s view, it sure is pretty. It looks like a distinctly “happy” little plane—rather like a playful character in a children’s book—and one can almost imagine a smile spreading across its cowling to greet its owner whenever the hangar doors are opened before a flight.

The impression of the CTLS being a “small aircraft” or any kind of “toy” evaporates as soon as one is seated in the bright, airy modern cabin. It is almost impossible to believe one is sitting in an LSA (a “microlight” to some). There is no doubt that this is a highly sophisticated real aeroplane; the modern “glass” instrument panel, incorporating two Dynon Avionics displays (one on each side), looks as if it belongs in a much bigger aeroplane and immediately grabs one’s attention. An autopilot control unit—yes, the aircraft features a two-axis autopilot with altitude hold—sits alongside the left side pilot’s display, while an array of circuit breakers sits beneath the display on the right.

The standby altimeter and airspeed indicator that reside beneath the pilot’s flat-screen display are the only traditional instruments remaining on the beautifully laid out panel.

The top half of the centre console between the pilots’ displays houses a Garmin 495 GPS unit above a Garmin SL40 radio and GTX327 transponder. Beneath these, in the vertical console that runs down to the throttle quadrant, are the avionics master switch and various lighting switches. At the bottom of this centre console are the (appropriately aerofoil-shaped) flap switch, an LED flap position indicator, ignition switch, ELT switch, instrument lighting switch, a couple of circuit breakers—and the most sensible, uncomplicated and pilot-proof fuel valve lever in existence.

Flight Design has made it impossible for a pilot to mismanage his or her fuel (short of a pilot being stupid enough to run out of the stuff altogether). Not only is the fuel valve either “Open” or “Closed”, but also, it cannot possibly be left “Closed” by mistake. As can be seen from the accompanying photos, the fuel lever must be lifted up into the “Open” position in order for the ignition to be switched on. Furthermore, in addition to the electronic fuel gauge readout provided by the Dynon display, Flight Design has incorporated clear sight gauges at the wing roots inside the cabin (like those in the Piper Cub) for a visual check of the fuel level in the tanks.

The throttle resides in the centre of the console running between the two seats. To its right is the single brake lever (the aircraft does not have differential braking, but uses a single lever in conjunction with nosewheel steering). Immediately to the left of the throttle is the choke lever, and on the far left is a small knurled pitch trim wheel and pitch trim indicator.

For those CTLSs fitted with variable pitch propellers, the pitch control lever sits (slightly unusually) behind the other levers in the central tunnel just ahead of the aileron and rudder trim controls (yep—the CTLS has aileron and rudder trim too!).

Just to add to the slight confusion for experienced CSU practitioners, for some reason, Flight Design have coloured the throttle lever knob blue (traditionally the colour of the pitch control knob), and the pitch lever knob black (traditionally the colour of the throttle knob). However, in all seriousness, it is unlikely that anyone would be genuinely confused by the layout, which works very well (and, after all, Beechcraft confused everyone for years with the juxtaposition of their throttle and pitch controls, which they further confused everyone with by colouring them both black).

Two notable features of the CTLS are apparent wherever one looks at the aircraft—its quality and safety. The aircraft just exudes quality, from its flawless finish—inside and out—to the smallest of thoughtful touches that abound throughout the design that make the aircraft as “user friendly” as possible.

Most importantly, the CTLS is about as safe as it is possible for an aircraft to be. The carbon-aramid composite fuselage structure is designed as a “safety shell” with the ability to absorb energy and protect its occupants. In addition, the engine mount points are designed to avoid the possibility of the engine intruding into the cabin in the highly unlikely event of a crash. It also features strong windshield support pillars and a strong overhead structure. The occupants are restrained by four-point safety harnesses and the aircraft is fitted with the ultimate safety “last resort”—a ballistic recovery parachute.

Somehow, despite having such a wonderfully strong structure, the CTLS retains outstanding visibility for its occupants that makes it an absolute joy to fly and travel in.

As part of its certification, the CTLS has been subjected to numerous tests that far exceed those required to ensure minimum LSA airworthiness standards.

The CTLS is so safe and so foolproof that if someone were to die in a CTLS crash, he or she would have to have been so deliberately stupid that this writer (with no sense of political correctness at all) suggests the human gene pool would probably benefit from his or her absence.

Where it counts

Obviously, the true test of any aircraft is how it actually flies. In this regard, the CTLS is almost impossible to fault. The aircraft is powered by the ubiquitous Rotax 912 ULS engine (which, interestingly, features carburettor heat, unlike many other Rotax-powered aircraft) and provides 100 hp at 5,800 rpm. With a maximum-weight climb rate of around 800 feet a minute, at anything below MAUW, the CTLS goes up like a champion pole-vaulter.

Its slippery shape means it accelerates rapidly, cruises quickly and glides well. With 130 litres of fuel available to the abstemious Rotax, the aircraft has an excellent range. At maximum all-up weight and a speed of 97 knots, its range is 830 nm (with a 100 nm reserve). At an economical 75% cruise, the engine only burns around 18.5 litres an hour, so its potential seven-odd hour endurance is far greater than most pilots’ bladders or buttocks can endure in comfort.

The CTLS features a “reflex” flap setting of minus 12 degrees, which, when applied, feels like a “power” switch being turned on and accelerates the aircraft quickly from 100 knots to a normal cruise speed of around 120 knots TAS.

The inherent safety of the CTLS is further evidenced by its benign handling at the stall. Tim Harrison provided a seemingly impossible demonstration to highlight this. He raised the aircraft’s nose to around 50 degrees to slow it down, and then, holding it there as a distinct buffet commenced, deliberately rolled the aircraft approximately 30 degrees. The (albeit rusty) pilot within me cringed inside as I prepared myself for the “inevitable” uncomfortable consequence I would have expected from a typical GA aeroplane.

Instead of dropping a wing violently in protest, the gentle little CTLS politely sighed—as if in disapproving resignation at the deliberately appalling bad handling— and simply levelled its wings and dipped its nose back to a straight and level attitude. It was a great demonstration of the effectiveness of the CTLS as a safe trainer. Without risk of terrifying a “newbie” with a violent wing-drop stall, the CTLS will still demonstrate all of the important stall characteristics effectively.

The CTLS’s controls are a feature that I think also contributes to its value as a trainer. While most new LSA/microlight aircraft have particularly light controls (which experienced pilots love), these can take some getting used to for new pilots. The controls in the CTLS were somewhat heavier than I had expected, which means they will not be “too sensitive” for new pilots. While definitely not uncomfortably heavy, they are quite firm (particularly in roll). However—importantly—they are beautifully direct and immediate with no “slop” or free play.

The efficient wing of the CTLS confers the aircraft with a glide ratio similar to most GA types. When the power is reduced in many LSAs and microlights, they tend to plummet rather like streamlined gold bars. Not so the CTLS, which just keeps flying—very much like a Cherokee or C172—another factor making it a good training platform for student pilots who will immediately feel at home in the circuit when they fly larger GA types.

The CTLS’s main undercarriage legs are fibreglass units that give a firm (but still comfortable) ride on the ground and make the aircraft feel sturdy and solid. The nosewheel is fitted with urethane polymer shock absorbers that provide good damping and work well with the fibreglass main gear to make for smooth landings.

The aircraft’s occupants enjoy effective heating and ventilation, and there is a small “jacket shelf” inside for light luggage (like jackets!) as well as baggage storage behind the cabin accessed by external doors. Practical shelves beneath the instrument panel provide manual and chart storage space, and small pockets on the cabin doors provide additional space for small light items like folded charts or flight computers.

The wide “gull-wing” cabin doors are supported by gas struts. With no wing struts in the way and the fuselage sitting at an ideal height from the ground, entry to and exit from the cabin is a breeze—another great feature that adds to the aircraft’s suitability as a trainer.

With a cabin width of 1.24 metres (49 inches), the CTLS is fully 240 mm (9.5 inches) wider than the four-seat Cessna 172. This makes for a very comfortable, roomy and relaxed atmosphere that is accentuated by the cabin’s veritable acres of well-placed glazing. Anyone who has done a bit of flying in conventional GA types will immediately fall in love with the space in this “egg with tail feathers” and vouch for the old saying that “beauty comes from within”!

The CTLS is a beautifully built and finished aircraft. It is economical, roomy, has great “legs” and performance, and the stable feel of a bigger aircraft. While the CTLS is not cheap (what is, in the current climate?), the standard aircraft comes comprehensively equipped with many features that are expensive options on most other types. Despite being fitted with most of the “bells and whistles” as standard, Flight Design offers a number of other useful options such as a glider-towing hook (ZK-FDB has a tow hook fitted), large “tundra” wheels and a photography window.

It is easy to see why Sports Aircraft New Zealand settled upon the Flight Design range of aircraft when Ruud van der Zwaal and Tim Harrison decided to give up the heavy metal and re-enter the GA world as LSA distributors. Their enthusiasm for the Flight Design aircraft they now distribute is infectious when one realises it is based on their (combined) eight decades of global flying experience and a great deal of careful research into choosing the “right” machines.

Don’t be surprised to see increasing numbers of Flight Design LSAs appearing on flight lines at flying schools or in private hangars around New Zealand. If you get a chance, fly one—you’ll be impressed.

Thanks to (Sir) Rudi van der Zwaal, Tim Harrison and their long-suffering and highly supportive wives, Caroline and Carol, for their hospitality and making their CTLSs available to Pacific Wings.