This promising concept has been going a while now, but as yet does not seem to have come to fruition.

One of the primary design objectives was a 210 mph plus, long distance cruising machine. Having 450 HP available in a reasonably light aircraft for its size is certainly an asset in achieving the desired performance goals. The low power loading numbers translate into fairly impressive short field take-off capability and climb performance. Performance estimates predicted the design goal of 210 mph cruise at 75% power at 9000 feet. Drag data computed from stock G model Staggerwings and statistics from typical, current generation, composite aircraft predicted fairly impressive top speed numbers. The design dive speed is 320 mph. Stall at gross is about 56 mph with flaps deployed and 67 mph retracted. The low stall speeds are a result of the wing area, and the four plain flaps. Rate of climb with the aircraft lightly loaded is quite spectacular. Climb analysis computes a 3200 fpm climb rate at 65% gross weight and 1900 fpm at gross.

The Pratt & Whitney R-985 Wasp Jr. engine is a derivative of the Pratt 1340 cu. in. Wasp engine. This engine is currently flying on numerous antique aircraft and has seen extensive use in the agricultural aerial application industry. The R-985 has a remarkable history as a durable and reliable source of power. Although no longer in production, there exists a sizable inventory of these engines in circulation with many becoming available as agricultural planes upgrade to turbo-props and Beech 18's are removed from service. New and surplus parts are readily available to support replacement of essentially all engine components. The R-985's ability to burn auto fuel makes it an even more attractive powerplant.

Lionheart is a modern derivative of the "Learjet of the 30's", the Staggerwing Beech. The negative stagger biplane arrangement provides numerous advantages, some aerodynamic and some construction related, but also represents a classic elegance not duplicated until now. A Pratt & Whitney R-985 radial engine was selected for the baseline design as a plentiful, reliable, and low cost horsepower/dollar powerplant that ultimately inspired the overall Lionheart configuration. Lionheart's overall size is very similar to the stock Staggerwing, but the cabin interior is lengthened slightly to provide Baron class 6-place seating.

The Wing System: The biplane wing system provides adequate wing area necessary for the desired low stall speed using a simple flap system. Lionheart's wing area is about 20% less than that of the Staggerwing because it's empty weight is lighter by about 600 pounds. A low stall speed was one of the key design requirements to provide relatively low energy, emergency, engine-out landing capabilities. Some maximum speed was sacrificed to achieve this goal, but this compromise gives comfort to those of us who are safety conscious. The builder will have to make twice as many wings but they will be easy to assemble and relatively small (about 13 feet from wing root to tip). Unlike the Staggerwing, both wings are cantilevered, so no struts or wires are necessary. Laminar flow airfoils are used on all wing surfaces. The wing root airfoil is a modern derivative of the 64-215, tapering to a 64-212 at the tip. No washout is used in the wings because of the "canard-like" stall characteristics of the negative stagger arrangement. Due to the induced airflow from the lower front wing, the top wing is flying at a slightly lower angle of attack during a stall. This means the front wing unloads before the top wing resulting in a gentle nose down at the stall break. The stock Staggerwing's gentle stall characteristics are due to this well known effect.

The Cabin: The fuselage is about 20 feet long from firewall to rudder post making Lionheart a cabin class aircraft that can be constructed in a relatively small space. Interior cabin volume and seating is similar to the Malibu but wider at the shoulders. Cabin width at the pilot/copilot seats is about 50 inches and widens to a maximum width of 51 inches near the second row of seats. Cabin width at the aft seats is about 42 inches. Cabin height at the pilot/copilot seats is about 52 inches and tapers to about 42 inches at the aft seats. A small aisle exists between the first two rows of seats. Cabin access/egress is via a single split door between the mid and rear seats on the left side of the fuselage (ala Malibu and Staggerwing).

Lionheart has been designed to accommodate 6 full size, FAA 170 lb passengers, but a 95% human model (6'-4") was used to verify interior space for the pilot/copilot. The aircraft is designed with a 4200 lb gross weight at +6,-3 G limit loads. Following structural testing the gross weight is increased for +4.4,-2.2 G limit loads (utility category). With an estimated empty weight of 2250 to 2300 lbs, Lionheart has a payload of about 1900 lbs. Just about right for the wife and kids... and lots of fuel.

Controls: Dual control sticks are designed for the pilot and co-pilot seats. Ailerons and elevator are pushrod actuated while the rudder is cable operated. The four ailerons and flaps of the upper and lower wings are interconnected at the wing roots via cables. With the exception of the landing gear attachment fittings, the upper and lower wings are identical.

Landing Gear: Lionheart uses a fully retractable conventional (taildragger) landing gear. The mains use pressurized gas for spring and damping while the tailwheel is sprung via a gas charged air/oil cylinder. Retraction is accomplished using electro-hydraulics. Landing gear track and wheelbase are both wider and longer than the stock Staggerwing, so ground handling is improved.