Of course, in terms of ultralight flying, the dawn of time was the late 1970s, when ultralights evolved from powered foot-launched hang gliders. By the early 1980s, in the golden age of ultralight flying, the North American market was dominated by such aircraft as the Eipper Quicksilver, the Ultraflight Lazair and the Pterodactyl Ascender. A surprising number of those 25-year-old designs are still around in refined form. The Quicksilver is still produced by several companies, the Lazair may be produced again soon and the Ascender is still available, too. Discovering that the kit supplier for the Ascender, DFE Ultralights, is just over the border in Pennsylvania, recently gave me the opportunity to take a trip down and fly the plane. 

A bit of history 

The Ascender started life as an unpowered flying wing hang glider. Created by

 the renowned glider designer Klaus Hill, it was produced in the mid-1970s by Manta Products as the Fledge. The developer of the Fledge design as a powered aircraft was California ultralight designer Jack McCornack.

He originally built a powered Fledge, producing it as the Pterodactyl Pfledge. He was really into using silent letter “P”s in those days. The plane was a flying wing and used weight shift for pitch control with tip rudders for roll and yaw.  

McCornack’s company, Pterodactyl Limited, produced increasingly refined versions of the plane through the late 1970s and early 1980s. After the Pfledge came the NFL (“Not Foot Launchable”), the Ptraveller and finally the Ascender. The Ptraveller was the first model to sport the characteristic canard surface.  

The Ascender was named after a World War II prototype fighter called the Curtis XP-55 Ascender. It was an unusual “tail-first” design, like the Pterodactyl Ascender. Naturally it is appropriate that a tail-first design should be called an “ass-ender”, as many pundits have pointed out over the years. 

The Ascender went through several improvements during its life span, the original model giving way to the improved Ascender II, then the beefier Ascender II+ and finally the two-seat Ascender II+2.  

After the ultralight and light plane economic bust of 1984, when everything from Lazairs to Cessnas went out of production, Pterodactyl changed hands. The new concern, Freedom Fliers, produced only a few Ascenders before they disappeared from sight. By that time, more than 1,000 of all models had been built. 

Even then, in the late 1980s, pilots kept flying their Ascenders. Many people consider them the finest ultralight ever designed and that kept the demand for parts high. A computer software designer, Dave Froble, was a former Pterodactyl dealer who owned three of the planes. He started looking for parts in 1988 and came to the conclusion that if the planes were going to continue to fly then someone should produce the parts needed. He formed DFE Ultralights Inc (Dave Froble Enterprises) to take care of the Pterodactyl spare parts market. Froble located sources for all the parts and by 1993 was able to supply any part that Pterodactyl owners needed. He started getting requests for whole wings and larger assemblies. From there it was an easy decision to supply complete kits. 

DFE Ultralights offers three models currently. The Ascender IIIA is basically an improved Pfledge, with no canard surface. Pitch is controlled by weight shift as in the original Pfledge. The Ascender IIIB is the standard model and is an evolution of the Ascender II. The Ascender IIIC is the updated version of the old Ascender II+, with bigger spars and other strengthening for bigger pilots and loads. The two-seater is an Ascender IIIC with the “side car” bolted on. The second seat sits off-centre on the right side of the pilot. It was originally developed as a trainer version, but has been used for cross-country touring as well. 

When Pterodactyl first offered the two seat Ascender II+2 in 1983 it was introduced to the public by a remarkable flight. McCornack packed up a woman journalist from an ultralight magazine, 10 gallons of fuel and, with over 100 pounds of camping gear aboard, set off cross-country. Most of the gear went into the Dacron-covered wings, as they are accessible by the inspection zippers. The lack of control runs through the wings makes them available for stowage. They arrived back at the Watsonville, California factory a week later, after covering 1025 miles to Mexico and back, without ground support! The aircraft weighs 250 lbs empty and carried more than 500 pounds on that trip with a 30 hp Cuyuna two-stroke engine. McCornack always insisted that his planes were designed to go places and not just to be flown locally. 

Walking Around 

It was the chance to fly the Ascender II+2, or rather the improved model, the DFE Ascender IIIC, which brought me to Froble’s facility near Vanderbilt, Pennsylvania. 

It was an early morning in August 2001 when we flew the Ascender. At Froble’s hilltop residence the day was warming up and fresh, with a bit of fog in the valleys and a slight breeze across his sloped runway at 90 degrees.

This aircraft we flew was actually produced by Pterodactyl in 1984 as an Ascender II+2. Froble has updated it to his current IIIC status, with such improvements as a steerable nosewheel and a Rotax 503 engine of 50 hp to replace the original Cuyuna 430 of 32 hp. He believes in scrupulously good maintenance and recommends disassembling the Ascender each year to inspect it and replace any worn out parts. This has the effect of creating an almost new plane each year. It sounds arduous, but the simplicity of the design means that one person can complete this type of annual inspection in a weekend. 

The detailed walk around revealed that the Ascender is a big aircraft. The wingtips are 6’10” off the ground and span 33 feet. The tip rudder tips are 10’ 2” from the ground. The wing area is 165 square feet with the canard adding another 11 square feet. The airframe is a surprisingly strong design of aluminum tube construction held together with aircraft-grade AN bolts. The wing is wire braced, with a king post to hold the ground wires in place. The main wheels are 20 inches in diameter, with a 16 inch unit for the steerable nosewheel. The aircraft is definitely designed for off-airport operations. The canard is of aluminum construction and is covered in clear Mylar. That makes it very easy to inspect the structure during the walk around. Froble “out-sources” many of his hard-to-make parts and it is notable that the complex bent canard ribs are produced by Canada’s own Murphy Aircraft of Chilliwack, BC. 

Going Flying 

We strapped into the comfortable sling-type seats and donned our helmets. In deference to the Rotax 503 right behind us we wore earplugs under our helmets, too. Froble pull-started the 503 and we warmed it up prior to departure. With about 7 gallons of fuel we were at about 648 lbs for take-off, some 102 lbs under gross weight. 

With the application of full throttle the plane accelerated very briskly, becoming airborne in about 240 feet, even with the cross wind. We climbed very quickly with full throttle until Froble reduced power to a more leisurely cruise climb. At 200 feet I was given control and the chance to feel out this interesting control set-up. The Ascender has only a side-stick controller. Fore and aft movement controls the canard through a direct push-pull tube. Side movement of the side-stick deploys the rudder on that side only. The rudder is really a drag device that slows that side of the wing. Due to the pronounced dihedral and sweep of the wing that drag induces a yaw and roll movement. On paper you expect that the plane will yaw and then, after a lag, roll into an uncoordinated turn, rather like flying a Cessna or Piper with the rudder only. In the air the handling is actually very precise and surprisingly pleasant. Lateral stick movement produces an immediate and well-coordinated turn that is very easy to control. The roll rate at 45 mph is about 4 seconds from 45 degrees to 45 degrees. That is actually quite impressive for that airspeed in any aircraft. 

The pitch control is agile and immediate. This is expected, as he whole canard moves with the stick. The canard acts really more like a large trim tab than an extra lifting surface as the plane evolved from a flying wing design in the first place. In cruise flight the canard flies along in neutral and the symmetrical airfoil is aerodynamically unloaded.

Stability checks reveal that the Ascender is stable in all axes. It flies itself hands off very well. Induced rolls are well dampened and the aircraft returns to level flight smoothly and without overshooting. There is no Dutch roll tendency. That isn’t really a surprise with all the pendulum effect of the high mounted wing and the dihedral as well. An induced pitch up or down followed by releasing the stick allowed the Ascender to return directly to level flight. There were no unexpected oscillations and the pitch moment dampened out very quickly. 

In cruise we breezed along indicating 50 mph on the tube-type Hall airspeed indicator mounted out in the clean air forward of the canard. There doesn’t seem to be any error in its readings. A later check of the fuel consumption showed that we were burning about 3 US GPH. This aircraft doesn’t make the Rotax 503 work very hard, something that will probably predict a long engine life. Those figures, along with 10 gallons of fuel in the two under seat tanks give an endurance of 3.3 hours and a range of 142 miles with a half hour reserve. 

Stalls were a non-event as any attempt to stall the wing resulted in the canard stalling first and the plane returning to level flight without altitude loss. 

I was keen to see how this two-axis control system would handle the cross wind on our return so we went home so Froble could demonstrate a landing on his short, uphill strip in the 5 knot crosswind. The approach was flown in a crab down to the runway. As the Ascender was leveled for touchdown Froble steered the plane into the wind slightly and touched the wheels down. As the Ascender slowed and the weight came onto the wheels the nosewheel steering become effective. We ate up about 250 feet landing the brakeless plane. Froble mentioned that that crosswind landing technique he used is effective up to about ten knots of wind. Above that figure a landing into the wind can be accomplished across almost any runway! 

The Ascender is a really enjoyable aircraft to fly – simple, responsive. It is also easy to maintain, as everything is readily visible and accessible, either directly or through the wings’ inspection zippers. Build times for this simple, pre-drilled assembly kit are reported to be 80-100 hours. Froble says that most builders finish them quicker than that but that he gives a high estimate so slower builders won’t be disappointed if it takes a bit longer to do a good job. The Dacron wing coverings save a lot of time over other fabric processes. 

The Ascender can be broken down in about 45 minutes to one 19-foot bag and the engine and wheels, without removing any locknuts. It all folds down for transport and can be carried that way by pick-up truck or van. It reportedly takes an hour to reassemble it. For that reason, many Ascenders are stored in garages at home. 

In Canada this aircraft is only available as a basic ultralight, as DFE Ultralights have not done the testing or paperwork to list it as an advanced ultralight and do not plan to do so. Currently that means that the second seat on the two-seater must be occuppied by a student flying with an instructor or by a second pilot with a licence that allows them to fly an ultralight. It might be possible to build an Ascender in Canada under the amateur-built rules, with some changes including the addition of some instrumentation, including fuel gauges. 

As is always the case with aircraft of this category, the Ascender is not a plane for everyone. It is slow in cruise speed and the no-windshield environment means that it is breezy. It is more like a motorcycle than a sedan. For fun on a summer day, including the ability to go cross-country, it is hard to beat.  

What is really attractive is the price. Froble runs DFE Ultralights Inc as a part-time business. He describes his ultralight flying as “what keeps me sane”. His main mission in life is to keep flying affordable and keep the old Pterodactyls flying with a supply of parts. That means that the Ascender kits are very affordable, even with the Canadian dollar as low as it is right now.

The DFE kits are very complete and include absolutely all the parts required to complete the planes, including the airspeed indicator and mounting bracket! The complete DFE Ascender IIIB single place kit, including the 2si 430 engine, is currently $7,900 US, which is about $12,200. The two-place version of the Ascender IIIC with a Rotax 503 engine can be built for about  $9,950 US (currently about $15,400). It is hard to find another two seater on the market in that price range, especially one with the lift capacity of the Ascender IIIC. 

For more information contact
DFE Ultralights,
170 Grimplin Road Vanderbilt,
PA 15486, USA,
724-529-0450,
e-mail at davef@tsoft-inc.com.
 
By Adam Hunt
Originally Published in the October 2001 issue of Canadian Flight
The publication of the Canadian Owners and Pilots Association