Rihn Design Series DR-109

Two seat aerobatic aircraft - competition and aerobatic training

Design Features
Low wing monoplane with a specially designed symmetrical airfoil, 16% thick, conic nose and flat sides. Large symmetrical ailerons. Wire braced tail surfaces. Solo from rear seat. Cockpit equipped with dual control sticks, dual rudder pedals, dual throttle, dual propeller controls, dual trim controls, dual brakes, and dual instrumentation.

Fuselage has a welded steel tube truss covered with sheet metal from the firewall aft to the cockpit, aft the tail. Aluminum sheet metal turtledeck. The tail surfaces are fabric covered and wire braced with steel tube spars and bent up steel sheet metal ribs. The one piece wing is all wood, Douglas Fir Box main spar, Douglas Fir spars, plywood ribs and plywood covered. Large span ailerons are built of wood and are plywood covered. The fiberglass engine cowl in a two piece, split horizontally and is easily removable for ease in maintenance.

Flying Controls
Pushrod actuated ailerons and elevator, cable actuated rudder. Ailerons are mass balanced and aerodynamically counterbalanced. Each aileron is fitted with a ground adjustable balance surface suspended below the aileron. A trim tab on each elevator also acts as a servo tab to reduce stick pressures.

Power Plant
Three engine options are available: AEIO-360 A1E6, 200 HP , AEIO-540 D4A5, 260 HP, AEIO-540 L1B5, 300 HP. The prototype DR-109 is equipped with an AEIO-540 D4A5, 260 HP. Driving an MTV-9, three blade variable pitch constant speed propeller. The main fuel tank is located in the fuselage ahead of the cockpit, capacity is 30 gallons, auxiliary fuel for cross country is located in the wing, capacity is 16 gallons. Total fuel capacity is 46 gallons.

Landing Gear
Non-retractable tail wheel type, main gear is a one piece aluminum spring, tail wheel is steerable and full swivel mounted on a cantilever steel spring. Main wheels are 5.00 x 5 with hydraulic disk brakes.

Each cockpit seat has an adjustable seat back nominally reclined to 30 degrees and is equipped with a five point aerobatic seat belt system.

Electrical system of 12 volts. Electric engine starter. Terra VHF radio. Terra transponder with encoder. Grand Rapids Technology Engine Information System (front and rear cockpit). Sigtronics voice activated intercom.

wing span
wing area
empty weight
useful load
gross weight
fuel capacity
Lycoming 200/260/300 HP
22 ft
5.5 ft
24 ft
114 sq ft
1260/1350/1420 lbs
690/900/900 lbs
1950/2250/2320 lbs
30/45 x-country
404/450/430 mi


takeoff distance, ground roll
rate of climb
max speed
cruise speed
landing distance, ground roll
service ceiling
600 ft
192/205/215 mph

limiting and recommended speeds

design manoeuvring speed (Va)
never exceed speed (Vne)
stall, power off (Vsl)
landing approach speed
58 Solo/60 Dual mph

All specifications are based on manufacturer's calculations