Piper PA-11 Cub
Single-engine two-seat high-wing civil monoplane

Archive Photos ¹

Piper PA-11 Cub (N4568M, s/n 11-71, 1947) c.1998 performing at the Old Rhinebeck Aerodrome, Rhinebeck, New York (Photos by John Shupek)

Piper PA-11 Cub (N4568M, s/n 11-71, 1947) c.2004 performing at the Old Rhinebeck Aerodrome, Rhinebeck, New York (Photos by John Shupek)

Overview ²

Piper PA-11 Cub
• Role: Personal use aircraft
• National origin: USA
• Manufacturer: Piper Aircraft
• First flight: August 1946
• Introduction: 1947
• Status: still in operation
• Primary user: private pilot owners
• Produced: 1947-1949
• Number built: 1,541
• Developed from: Piper J-3 Cub
• Variants: Piper PA-18 Super Cub

The Piper PA-11 Cub Special is a later production, two-place variant of the Piper J-3 Cub light propeller-driven aircraft, manufactured by Piper Aircraft.

Design and Development ²

The airframe is basically the same as a Piper J-3, but the engine mount is slightly lower, the windshield more sloped, the cowling is fully closed and the fuel tank was raised and placed in the port wing. Both seats were slightly moved Back, and solo flying was usually from the front seat. Early PA-11’s had a Continental A65-8 engine, while the later ones had the option of a Continental C90-8.

Several current-production light-sport aircraft are being produced based on this configuration. On the early PA-11’s, the fuselage was painted with a metallic blue on the lower half the rest being Lock Haven Yellow. The later PA-11’s were all yellow with a simple brown stripe.

The aircraft formed the basis for the next evolution in the Piper Cub series: The Piper PA-18 I. The PA-11 and its successor, the PA-18-95, share many common traits. With a gross weight of 1,220 lbs. and average empty weight of 850 lbs., the PA-11 is a light enough to perform well, yet heavy enough to maneuver easily in more wind than the lighter J-3 Cub. The PA-11 is capable of short takeoffs and landings, yet has a respectable cruise speed for its configuration. Given that the PA-11 falls into the modern day category of light sport aircraft it is a popular airplane to acquire and commands a premium price.

Modifications ²

The PA-11 was one of the first aircraft to be used in experiments with the nose-wheel (also known as tricycle gear) configuration. Although its original design is intended to be a tail-dragger, a modification was created to mount a nosewheel onto the front of the aircraft. The nose-wheel is attached to the two rear engine mounts by y-shaped steel tubes attached to a steel tube with a shaft that slides freely with the wheel. Cables ran underneath the belly directly from fixtures on the rudder pedals to the nosewheel shaft. This gave the ability to steer by pivoting the nosewheel shaft with the rudder pedals. The shock system consisted of six circular bungee chords, sometimes four for softer landings, located on either side of the nosewheel shaft to ears on the top tube and the bottom shaft connected to the wheel. In order for the aircraft to balance properly with the nosewheel, the main gear was flipped around so that the center of balance would move forward. The pilot would sit in the front seat for added balance. Most PA-11’s in service today retain the original tailwheel undercarriage layout.

Variants ²

• Piper PA-11 Cub Special: Two-seat light aircraft, powered by a 65 hp (48 kW) Continental A65-8 piston engine.
• L-18B: Military version of the PA-11 Cub Special, powered by a 95 hp (71 kW) Continental C90-8F piston engine. 105 built and delivered to Turkey, under the Military Assistance Program.

Military Operators ²

• Israel: Israeli Air Force
• Turkey

Specifications (PA-11) ³

Type

• Two-seat light cabin monoplane.

Wings

• High-wing braced monoplane.
• Wing structure of Spruce spars and aluminum-alloy ribs, the whole being covered with fabric.
• Steel-tube Vee bracing struts.
• No flaps.

Fuselage

• Rectangular welded steel-tube structure covered with fabric.

Tail Unit

• Braced monoplane type.
• Welded steel-tube framework covered with fabric.

Landing Gear

• Fixed divided type.
• Two side vees and half axles hinged to cabane below fuselage.
• Rubber cord shock-absorption.
• Hayes wheels 841 (8.00 × 4 tires).
• Hydraulic expander tube brakes.
• Leaf-spring steerable tail-wheel.
• Alternatively twin-float or ski undercarriage.

Power Plant

• One Continental A65-8 four-cylinder horizontally-opposed air-cooled engine developing 65 hp at 2,300 rpm.
• Sensenich two-Blade fixed-pitch wooden airscrew.
• Fuel capacity 12 US gallons (45 liters)
• Oil capacity one US gallon (3.7 liters)
• Continental 90 hp engine may be installed to order.

Accommodation

• Enclosed cabin seating two in tandem with dual controls, either set being removable.
• One-piece Plexiglas windscreen.
• Baggage compartment aft of rear seat.

Dimensions

• Wing span: 35 ft 2½ in (10.72 m)
• Tailplane span: 9 ft 6 in (2.89 m)
• Length: 25 ft 4¼ in (6.82 m)
• Height: 6 ft 8 in (2.03 m)
• Wheel track: 5 ft 11 in (1.80 m)
• Propeller diameter: 6 ft 0 in (1.829 m)
• Baggage compartment: 10 × 11 × 24 in (25.4 × 28 × 61 cm)

Areas

• Wing area, gross: 178.5 ft² (16.58 m²)
• Aileron area (total): 19.2 ft² (1.78 m²)
• Fin area: 4 ft² (0.37 m²)
• Rudder area: 6.5 ft² (0.60 m²)
• Tailplane area: 14.7 ft² (1.36 m²)
• Elevator area (total): 11.6 ft² (1.67 m²)

Weights

• Weight empty: 730 lb (331 kg)
• Disposable load: 490 lb (222 kg)
• Weight loaded: 1,220 lb (553 kg)
• Baggage allowance: 20 lb (10 kg)

Loadings

• Wing loading (fully loaded): 6.8 lb/ft² (33.2 kg/m²)
• Power loading (fully loaded): 18.76 lb/hp (8.48 kg/hp)

Performance

• Maximum speed, fully loaded, no wind at sea level: 100 mph (160 km/h)
• Cruising speed: 87 mph (139 km/h)
• Landing speed: 38 mph (61 km/h)
• Climb: 514 ft/m (157 m/m)
• Absolute ceiling: 16,000 ft (4,880 m)
• Cruising range: 300 miles (480 km)
• Take-off run: 350 ft (107 m)
• Landing run: 290 ft (88 m)

References

1. Photos: John Shupek
2. Wikipedia. Piper PA-11
3. Bridgman, Leonard. (editor). Jane’s All The World’s Aircraft 1949/50, Sampson Low, Marston & Company, Ltd., London, 1949, page 268c