Durand Design Doesn’t Stall

July 27, 2018 - Negative stagger biplanes, where the top wing leading edge is aft of the lower leading edge, are a concept that occasionally shows up in both commercial and experimental designs. There are good reasons for the configuration. One is the good visibility the setback upper wing allows, but another is behavior in the stall.

“It is virtually unstallable,” said Jim Swatosh, EAA 1108191 of Stillwater, Minnesota, and current owner of the original Durand Mark V biplane. “This was all by design of course. When the plane goes into a climb and into a stall situation, it just drops, then raises. One wing stalls, and the other wing raises [it back up].”

Originally built by the type’s designer, William H. “Bill” Durand, Jim’s plane is the first example of the type and made its first Oshkosh appearance back in 1978.

Durand actively flew the craft for a number of years. He made plans available and, according to Jim, approximately 15 examples eventually made it into the air. A number of them continue to fly to this day.

Jim acquired the title to the airplane and the underlying design in 2015. It had not flown for more than 30 years and did require a bit of repair to get it into the air. Since then about 40 hours have accumulated on the tach up until its visit to EAA AirVenture Oshkosh 2018.

The two-seat, all-metal biplane cruises at 130 mph while burning 8 gph in its Lycoming O-320 engine.

Roll control leverages spoilers in lieu of ailerons, allowing space for four full-span flaps.

Pilots report that the design’s handling qualities are superb, and the plane nearly flies itself.

Jim said cockpit ingress, egress, and comfort is a key feature of the Durand design. With the forward sliding canopy open, passengers and pilots simply step into the plane standing up, get situated, and sit down. The canopy rides on a set of ball bearing slides and virtually closes itself once the pilot releases a small latch.

Other comfort features include adjustable seats and a cabin air exhaust system.

Jim’s airplane includes a steerable nose wheel that provides simple handling on the ground. Tailwheel configurations are an option, and at least one builder equipped a Mark V with floats.

Jim is selling plans on his website at www.DurandMarkV.com. He just completed a full 3D rendering of the craft in SOLIDWORKS and is making that data available to prospective builders as well. He is also considering offering a kit, if there is enough demand.

The classic Durand is tied down just east of Homebuilders Headquarters.