LOUDENSLAGER/ZIVKO SHARK – N310LL
June 20, 2002, saw the roll out of Leo Loudenslager’s “Shark” aerobatic airplane from the Zivko Aeronautics Inc. (ZAI) facility. Loudenslager was Zivko’s first customer in 1989 when they were employed to rebuild his Budweiser Microjet.
Loudenslager’s aerobatic record was amazing. A seven-time winner of the US Aerobatic Championship and the 1980 World Aerobatic Champion, Loudenslager was an extremely well accomplished aerobatic pilot. Other achievements include induction into the Aviation Hall of Fame of New Jersey; induction into the Aerobatic Hall of Fame; awarded eight gold, five silver, and three bronze medals in world competition; recipient of the Art Scholl Showmanship Award; the Bill Barber Showmanship award; the Clifford Henderson Award, and the first aviator to receive the Victor Award.
Loudenslager had built his own aerobatic airplane called the Bud-Light Laser 200. It was a more traditional aerobatic monoplane, but Leo had bigger dreams of an extremely agile aerobatic airplane that would put him far ahead of the competition. With his obsession of an extremely high power to weight ratio, Leo felt that ZAI had the expertise to bring his dream airplane to reality.
In 1991, in conjunction with Loudenslager, ZAI began development of the Shark. The Shark would be very different from any other aerobatic airplane, built from high-tech materials and with control surface deflections of +60 degrees. The airplane would be capable of the most impressive and precise aerobatics of its day.
The engine was initially a Lycoming AEIO-540 that was modified by removing excess material in order to reduce its over-all weight. This engine was going to be used during test flights then swapped for an AEIO-540 that was modified to both increase horsepower and reduce weight. The propeller was a standard Hartzell non-counterweighted composite aerobatic propeller. The empty weight was projected to be 930lbs, which later became quite accurate. The dry engine made up 48% of the empty aircraft weight.
Construction info: method of construction, materials Construction method for the composite parts was rather conventional with them being carbon fiber face sheets with a Nomex/foam core. Parts of the aircraft that are made from composites include the wing/aileron, horizontal/elevator, vertical/rudder/ventral fin, and engine cowl. The fuselage was made quite differently in that it was built using carbon fiber tubing, for all straight sections, with welded titanium tube clusters that the carbon tubing was bonded to. The fuselage was designed this way to reduce empty weight; the basic fuselage ended up weighing 35lbs compared to 75lbs for an equivalent steel structure. The mechanism for the empennage was fabricated from titanium, aluminum, or stainless steel, depending on the requirements. The aft portion of the fuselage that the empennage mechanism is attached to is a welded titanium tube structure that is bolted to special fittings bonded to the carbon tubes. This was done, primarily, to ease possible changes that might need to be made after test flying. The lower aft portion of the fuselage was covered in fabric. The remaining part of the fuselage was covered in thin magnesium sheet because of its weight advantage over aluminum sheet. The seat was a bolted in structural member of the fuselage, so it was fabricated of welded titanium with the actual seat supporting the pilot being a fabric material. The landing gear leg was quite special in that it was fabricated from titanium face sheets that were fusion welded to a titanium honeycomb core. The attach fittings at top and bottom of the gear leg were welded titanium box structures.
People who worked on the project, in house at ZAI were: Todd Morse: lead engineer, Leonard Hannasch: metal fabricator and titanium welding, Aimee Sanderson, Mark Prince, Paul Reinman: composite fabricators, Tom Smith: finishing, painting, Eric Zivko: fabric covering, conceptual design and final assembly. Pictured in photo are left to right: Bill Zivko, Judy Zivko, Eric Zivko, Todd Morse and Leonard Hannasch.
Believe it of not, maximum speed, stall speed, cruise speed and rate of roll were never really calculated in much detail. Everything was being designed in the lightest possible way and the resultant benefits would dictate items such as the rate-of-roll, climb rate, etc. The results would have been very spectacular.
The design goal of the project was to design an airplane that had, at minimum, a thrust to weight ratio greater than one. At zero forward airspeed, we were at 1.2:1 thrust to weight. In addition to the high T/W ratio, the empennage was designed to give the aircraft extreme maneuverability. The ultimate goal was to enter a vertical up line, while forward airspeed stopped at the top, pivot the aircraft around its’ wing tips a number of times while slowly descending. The aircraft would stop pivoting at a point where its’ nose was pointing up while power was added to make the aircraft again climb on the same vertical line where it entered the maneuver.
Unfortunately, the aircraft never did fly. On the day Leo's motorcycle accident, the aircraft was in the paint booth being painted. The project was approximately 30 days from first flight, the culmination of a seven-year project
The above construction information and photos have been provided by Eric Zivko of Zivko Aeronautics Inc.
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