Radical Light-Twin Experimental
An introduction to FPNA's A-36 Vulcan
By Nicholas Wood, EAA 831459, firstname.lastname@example.org
Photos by Nicholas Wood and Retanda Wood
The search for new opportunities in light aircraft brought the staff of Central Valley Sportplanes to the 2010 Sebring Light Sport Expo this past January. Our search for a new S-LSA to add to the flight line of our local light-sport outlet in California brought us to Florida and this year’s expo, which didn't disappoint. With the growing number of students in need of aircraft to train in, it’s become obvious to us that one S-LSA wasn’t adequate. Strolling down the thoroughfare of new aircraft stirred excitement for everyone, and it didn't take long for us to fulfill our mission. With our new wings ordered, we discovered a really good reason to consider offering our flight students multi-engine training on a single engine budget. And no, it’s not Tecnam's new twin. Although it isn’t certified as of yet, the A-36 Vulcan—a radical light twin experimental—promises to be an “affordable” certified twin.
This A-36 Vulcan was on display January 22 and 23 at the annual Sebring Light Sport Expo. Although it’s clearly not an LSA, it most defiantly commanded attention around FPNA’s display less than 300 yards from their fixed base of operations.
From left to right, Central Valley Sportplanes (CVSP) President Bill Campbell, Don Thomasson, CVSP staff Nick and Tanda Wood, and David Garden standing in front of FPNA’s booth during the expo in Sebring Florida.
Design and Purpose
Located directly on the airfield in Sebring Florida, Float Planes and Amphibs (FPNA) designs, builds, and flies their own breed of aircraft ranging from ultralights on floats, to weight shift, to their fixed-wing factory-built S-LSA like the high-wing Valor A-22, the Cape Town seaplane, right up to the twin-engine Vulcan.
The Vulcan was put on the drawing board by FPNA president and chief designer Shawn Okun in 2000. Once designed, a 1-year hiatus from it allowed Shawn to completely mull it over in his mind before starting the build process, putting serious thought into everything he wanted his new twin to be. When Shawn began designing the Vulcan, he set out to build a light, efficient, and high-performing twin for aerial photography (including mapping), law enforcement, border patrol, and someday, flight schools. He wanted high-performance capabilities with enough power to get in and out of unimproved areas even while operating on one engine..
Shawn joked that he used “every resource on the planet” when he was designing the Vulcan. At the time of design, he had 22 years of experience (including formal training) designing and building light, utility aircraft. The first prototype took to the air in late 2003, which was quickly followed by a second prototype being built and flown in 2004. Full production of the A-36 Vulcan took off in 2007, producing N198DT, an order placed by customer Don Thomasson.
Outside FPNA headquarters, the A-36 Vulcan is rolled out for early morning flights before being brought to the display arena Saturday morning.
After a thorough preflight inspection, Don pulls each prop through, circulating oil from the bottom of the oil sumps into the rest of the engine, a typical Rotax four-stroke procedure.
Don opted for twin Rotax 912S (standard certified) engines installed in his Vulcan and upgraded them to include preheating water jackets for the carburetors and gascolators, a feature included as standard equipment on many of FPNA’s certified aircraft.
Don’s first flight in his new aircraft was in 2008 and began with dual instruction from Shawn. He could have had the option to purchase a kit from FPNA and build his own, but he wanted a production-built model he could jump into, turn a key, and fly. Whether the customer prefers to build or buy, they will each have the added benefit of receiving this same training. From their fixed base of operations located at the Sebring Airport, FPNA offers instruction for every type of flying, from amphibs and floats to single- and multi-engine fixed wings, plus training for both weight-shift-control and powered parachutes.
When Shawn was preparing Don for his transition to the A-36, he started him off in the rear seat. Don had accumulated a lot of tailwheel experience; however, the side-mounted control stick would take a little time to get used to after years of flying tall yank-and-bank center sticks in his other airplanes. The Vulcan uses a short joystick cocked slightly inward and requires only very small inputs for aircraft control. The dual joystick controls are similar to what modern jet fighters are using, as well as modern airbus models. Shawn, who coincidently has a multitude of hours flying A320s, remarked even he had to quickly overcome the adjustment period with the controller because he was accustomed to flying with his left hand, the throttles on his right. The Vulcan’s controls are the opposite of this configuration, like many tandem and single-seat aircraft.
The Vulcan configuration lends itself to the large canopy tilting to the right, allowing both occupants to easily hop in and out of the cockpit (or pod as it’s sometimes called) from the port side of the airplane. With a little prepping from the back seat, Don was easily able to move up to the front seat. After that, it boiled down to cockpit familiarization, which was fairly simple because every control and switch was within easy reach. Managing trim with push-button controls on the joystick and adjusting the propellers and fuel, along with navigation equipment and GPS, would be mastered with confidence under Shawn’s tutelage.
A satisfied-customer-turned-FPNA’s marketing and sales director, Don Thomasson enjoys a full panoramic view from the cockpit of his A-36 Vulcan while taxiing from headquarters to the gates of the 2010 Sebring Light Sport Expo.
Compared to other tailwheel aircraft, the takeoff technique used in the Vulcan is a bit different. Normally the pilot would raise the tail, then rotate off the ground. This aircraft has so much power, all of which is located well above the pitch axis, and if power isn’t gradually added, the plane would want to pitch over more than the elevator would have the authority to counteract. Therefore the pilot must hold back pressure on the stick while gradually applying power, and when there’s sufficient airflow over the wing (and elevator) to neutralize the pitching moment from the high thrust line, the pilot can relax a little on the stick, making the tail come up. The other thing that takes a little getting used to is the nose, which tapers off radically since there’s no engine to look over. This creates an illusion of flying with a nose-down attitude, even during slow flight or after the flare. However, the landing characteristics of the Vulcan once it touches down on the mains is no different from any other tailwheel airplane. You can take off from plowed fields, land on grass or dirt, just preferably not in sand or mud for the sake of the engines.
As for the ups and downs of Don’s first flight, he explained the controls were very sensitive, and his sight-picture through the cockpit during landing was one of the biggest obstacles to overcome. He also remarked how heavy the aircraft felt, but Shawn attributes this to overcontrolling the joystick with wrist movement like most stick pilots are accustomed. The Vulcan’s joystick requires only subtle inputs and can be easily controlled with slight movements of the fingers rather than the entire hand and arm.
A unique feature found in the construction of the Vulcan is the utilization of fiberglass composite construction for the compound curves of the main portion of the fuselage, including the cockpit. Using a 43-ply lay-up, the preimpregnated (prepreg) glass is vacuum bagged and cured to create the finished product. The formed part is then trimmed and finished before assembly. The rear section of fuselage (empennage, wings, and tailcone) are all-metal structures, including their skins. This blend of metal and fiberglass is what gives the Vulcan it’s strong but lightweight configuration and lends the airplane its dynamic curves.
The Vulcan’s fuselage is a blend between fiberglass and aluminum; note the difference in surfaces where the compound curves of the composite pod meets the straight lines of the all-metal empennage and tail sections.
Sleek curves and inset features like the foot step below the forward seat add to the reduction of drag, contributing to the overall efficiency of its fuel-sipping engines.
Tandem seating and dual flight controls make up the spacious podlike cockpit with the large, rather heavy canopy tilting on the right side. Side consoles designed like armrests add to the comfort desired on long flights, with a control stick on the right and dual throttle controls mounted on the left, along with gliderlike sliding pull back flap handles. Both seats are formed into the pod and are very comfortable. Shawn explained he wanted the seats in the Vulcan to be as close to his favorite recliner chair as possible, like a La-Z-Boy on game day.
As a testimonial from this A-22 Valor pilot’s perspective, during the show at Sebring the author couldn’t find any seat around, not even in his plush hotel villa, that was as comfortable as the seats in Don’s Vulcan.
An optional navigational package includes an airspeed indicator, altimeter, vertical speed indicator, artificial-horizon, turn coordinator, and a magnetic compass, with options such as GPS, autopilot, and engine monitoring instruments. With certified engines, it’s possible to certify the aircraft for instrument flight rules flights. (Click for larger view)
The cockpit is equipped with heating and ventilation; as an option, there are provisions for the installation of an air conditioner. Pilot seats can be customized for the people that will be regularly flying the aircraft.
The Vulcan leads the way with a side stick control, thus the pitch and roll controls are actuated via a side stick. This ensures additional comfort for long flights, additionally freeing the space under the pilot seats for installation of optional equipment, such as a camera for aerial photography. Comfortable control is ensured by electrically actuated trim tabs on the stabilator (all-flying elevator) and the rudder.
The A-36 is a multipurpose light airplane, designed for a wide range of tasks. It’s possible to install a video camera in the nose of the fuselage and a panoramic camera under the pilot seats as well as a gyro-stabilized platform in the cargo compartment of fuselage. The Vulcan is also an excellent observation platform.
Located within the aircraft’s center of gravity (CG) just behind the rear pilot seat is a spacious cargo compartment. It’s designed to accommodate two regular carry-on-size luggage bags up to 220 pounds (100 kilogams). An upward hinged cargo door under the left wing grants plenty of access for loading cargo and uses a simple lightweight draw pin for holding it open.
Two Zeus fasteners secure the door closed during flight. Available space inside is used for housing an emergency locator transmitter (ELT), and more than enough space is available through the hatch to perform inspections and service booster pumps for all engines, which are located just inside the fuselage and behind the cargo bay.
The landing gear is designed with rough-field performance in mind and includes a large castering tailwheel mounted just below the trailing edge of the vertical stabilizer. The main landing gear assembly is constructed from fiberglass. The forward position of the mains, coupled with the large wheel in the rear, provides a tricycle-style view without the nose-high attitude of conventional gear, allowing for greater forward visibility when operating in and out of unimproved areas. Stepping on the left gear leg makes ingress and egress from the rear seat easier.
N198DT features sporty, low-profile wheel pants. However, the Vulcan can be outfitted with other various wheel types depending on what type of terrain the customer intends to operate from.
Vulcan utilizes a combination of features granting pilots outstanding short-field performance. High-lift characteristics of the wing design and efficient flaps, combined with a high power-to-weight ratio and in-flight adjustable propellers, all contribute to outstanding climb performance. The 37.5-foot wing span nets 168.6 square feet of wing area coupled with high-output Rotax pusher engines, allowing the Vulcan to climb at nearly 2,200 feet per minute under normal operation. Make a mistake and land on an angry farmer’s field? No problem—jumping back in and quickly taking off on a single engine alone, netting 800 feet per minute during climb out, will leave that pitch fork-wielding farmer in the dust. Maybe that scenario is highly unlikely, but it showcases possibilities for law enforcement or border patrol utilization..
The T-tail configuration makes efficient use of an all-flying horizontal stabilizer (stabilator) ensuring aircraft balance in a wide range of CG positions while maintaining good control responses. This provides an opportunity for using a pusher engine configuration with a large number of variants for equipment loading and placement while still permitting a great view for the pilot and passenger. Trim is included for both the rudder and stabilator and is controlled from the joystick using electrically actuated servomotors.
N198DT basks in early morning sunlight penetrating the hangar as early morning fog lifts from the rest of the field in Sebring. Across the hangar, a Cape Town float plane sits in waiting.
For long endurance, the airplane is fitted with two wing fuel tanks which have a combined capacity of 31.7 gallons/120 liters, ensuring an endurance of at least 5 hours. An additional tank with a capacity of 15.8 gallons/60 liters can be installed in the cargo compartment, thus increasing the endurance to over 8 hours.
Utilizing standard Rotax 912 engines, the Vulcan gains performance and efficiency while still being able to use automobile fuel, which helps to lower operating costs. With such high power-to-weight ratios, this aircraft can’t only maintain level flight on one engine—it’s capable of a single-engine climb and takeoff. This allows for continued operations, even with one engine if needed.
Maintenance of the engines is a breeze due to the relatively low position of the nacelles over the ground and the ease with which the cowlings can be removed.
Standard equipment on every A-36 Vulcan are in-flight adjustable Warp Drive propellers ensuring high takeoff thrust and fuel efficiency during cruise flight.
Additional options for FPNA’s A-36 Vulcan include the BRS ballistic recovery system, added interior lighting for night operations, and electronic flight instrument systems (EFIS). Customers may also choose to have an artificial horizon installed along with various GPSs available.
Build or Buy
Whether the customer wishes to purchase a factory-built noncertified model registered in the experimental/exhibition category or build his or her own from a kit and register it under the amateur-built experimental category, both can include the same cockpit arrangements, navigation, and engine arrangements available from FPNA.
This includes the buyer’s choice between two Rotax 912 UL 80-hp engines or optional 912 ULS 100-hp (noncertified) engines, altimeter, airspeed indicator, vertical speed indicator compass, slip indicator, electronic instrument system (EIS) specially made for multi-engine, two three-blade Warp Drive propellers, landing light, nav lights, strobe lights, Lynx interface, Microair radio, Microair transponder mode "c" equipped, ELT, luggage bay, all fairings, and customer’s choice of paint color (either red, white, blue, or yellow), as well as registration and shipping.
Experimental/Exhibition vs. Amateur-Built Experimental Categories
If the customer is comfortable with building within the realms of both composite and metal construction, a Vulcan kit from the manufacturer may be an ideal way to fly a Vulcan of your own. Depending on the individual builder’s desires, a multitude of different engines could be chosen and cost can be saved when equipping the cockpit to your own comfort and liking. Standard taboos and benefits would apply for the builder regarding any modifications made such as the use of engines other than Rotax. One benefit to building your own would be the ability to conduct annual condition inspections so long as the repairman's certificate was applied for by and issued to the builder/owner. It should be noted, though: The kit at this time hasn’t yet been evaluated for consideration under the FAA’s new 51 percent rules.
Perhaps a faster option: FPNA customers can purchase a complete factory assembled and equipped version of the A-36 Vulcan with all the bells and whistles. The aircraft will have to be registered under the FAA’s experimental/exhibition category, which can carry a few restrictions along with it. On the upside, though, a buyer choosing to go this route may find these minor restrictions to be no big thing. Limitations are typically set to include a 300-nautical-mile radius and could also limit operations over populated areas, though the latter can be lifted if the pilot meets FAA requirements for operation. Any flights conducted outside the radius of the aircraft’s fixed base of operations will require written notification in advance with approval from the local FAA Flight Standards District Office before the flight can be conducted. For many aircraft owners, this may be all that’s needed to enjoy thousands of hours of potential flying adventures.
Redundant fuel and electrical systems with a dual flight control system ensure perhaps the safest possible operation of the Vulcan. Two engines allow for long flights over terrain where emergency landings are undesirable or even impossible(sea, mountains, forest, desert).
Of course at this time, though, it would seem FPNA has missed a big mark and will continue to miss out until FAA certification can be achieved. Until then, flight schools like ours seeking affordable multi-engine operations and training will be limited to aircraft like Tecnam’s recently certified P2006T which also features certified Rotax 912S engines. However, owners of A-36 Vulcans will be capable of using their aircraft for personal training and instruction; they can’t be hired out for instructing others.
Finished A-36 Vulcan prices starting at $174,999.00.