A modern LSA triplane built using technology and engines from the ultralight industry, the Acrolite 1T is a strut braced, single place light sport triplane. Construction is of welded steel tube fuselage, riveted aluminum tube tail group, full sheeted box spar wing. The high aspect ratio of the wings allows an excellent rate of climb and a good glide ratio if the wing interference drag can be reduced, and give high roll rate from the short span wings. By utilizing a modern airfoil, narrow wing chord, lots of wing stagger and properly shaped wingtips the interference drag and the tip loss is reduced. The “quick build” wings use common wood working tools and full size patterns for all the fittings, controls, ribs, panels and bulkheads are supplied. The Triplane construction is identical to the 1B biplane except that on the prototype we used a fiberglas skin for the wings instead of plywood. This gave a much smoother surface to the wing than the plywood. The wings for the triplane are made with a wooden frame and covered with fiberglass or plywood. The remainder of the construction methods are the same as the biplanes. The aircraft accelerates and lifts off the ground very quickly and climbout is exceptional. With the ailerons on only the center wing the roll rate is still adequate. Compared to the biplanes aileron response is just a bit slow initially but once it starts moving it is quite good. It does not roll as fast as the biplanes but the turning radius is a lot smaller. The stall is more pronounced in the triplane and unlike the biplane that will fly itself out of a stall even with full back stick, the triplane requires proper stall recovery technique. In a 1000 ft climb out contest with the 80 hp biplane the triplane lagged only slightly behind. A full throttle, level flight, speed run showed 115 mph indicated at 6800 rpm. Visibility is very good, especially on approach and it feels easier to land than the biplanes because it does not seem to float as much at touchdown. Rudder authority is very good and it will make a flat turn. Flight testing was completed and the construction drawings and builders manual were completed and made available.
Engine: Rotax 582, 65 hp Reduction: 2.58 to 1 Propeller: 64 x 48 Airfoil: GA30U-211 Wingspan: 18 ft. x 3 Wing area: 111 sq.ft Aspect ratio: 20.8 to 1 Length: 15.5 ft Height: 6 ft Fuel capacity: 8 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 450 lb Gross weight: 720 lb Span loading: 13.3.0 lb/ft Wing loading: 6.5 lb./sq.ft Power loading: 10.8 lb/bhp Power off stall speed: 44 mph Power on stall speed: 40 mph Landing speed: 55 mph Maneuvering speed: 76 mph Maximum level speed: 110 mph Never exceed speed: 130 mph Cruise speed: 93 mph Best glide speed: 65 mph Best rate of climb: 1085 fpm Best climb rate speed: 75 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft Cockpit width: 24 in
Engine: Rotax 503, 50 hp Reduction: 2.58 to 1 Propeller: 62 x 43 Airfoil: GA30U-211 Wingspan: 18 ft. x 3 Wing area: 111 sq.ft Aspect ratio: 20.8 to 1 Length: 15.5 ft Height: 6 ft Fuel capacity: 8 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 450 lb Gross weight: 720 lb Span loading: 13.3.0 lb/ft Wing loading: 6.5 lb./sq.ft Power loading: 14 lb/bhp Power off stall speed: 44 mph Power on stall speed: 40 mph Landing speed: 55 mph Maneuvering speed: 76 mph Maximum level speed: 100 mph Never exceed speed: 130 mph Cruise speed: 85 mph Best glide speed: 65 mph Best rate of climb: 744 fpm Best climb rate speed: 70 mph Range: 250 sm Take off distance: 550 ft Landing distance: 500 ft
Engine: Rotax 582, 65 hp Reduction: 2.58 to 1 Propeller: 64 x 48 Airfoil: GA30U-211 Wingspan: 18 ft. x 3 Wing area: 111 sq.ft Aspect ratio: 20.8 to 1 Length: 15.5 ft Height: 6 ft Fuel capacity: 8 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 450 lb Gross weight: 720 lb Span loading: 13.3.0 lb/ft Wing loading: 6.5 lb./sq.ft Power loading: 10.8 lb/bhp Power off stall speed: 44 mph Power on stall speed: 40 mph Landing speed: 55 mph Maneuvering speed: 76 mph Maximum level speed: 110 mph Never exceed speed: 130 mph Cruise speed: 93 mph Best glide speed: 65 mph Best rate of climb: 1085 fpm Best climb rate speed: 75 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
The original single seat Acrolite biplane was designed in 1985 to take full advantage of the regulations governing ultralight aircraft in Canada at that time. Construction was started in January 1986 by Peter Eisenbach and Chris Weiher and the first flight was in October 1986. It was a 22 foot span biplane with an empty weight of 281 lb and powered by a Rotax 447 engine.
The Acrolite 1A was first flown with the Kawasaki 440 but after 50 hours that engine was replaced with a new Rotax 447 40 hp and a ‘B’ reduction drive. The fuselage is constructed of welded 4130 chrome moly steel tube and the tail assembly is constructed of 6061 aluminum tube riveted together with 2024-T3 aluminum gusset plates. The wing is of 2024-T3 aluminum with a channel section main spar, a channel section rear spar, sheeted leading edge D cell and assembled with 1/8 inch diameter stainless steel blind rivets. The airfoil is a NACA4412 semi-symmetrical section. The ailerons are semi-full span aluminum tube, static balanced. The wing, fuselage, empennage and ailerons are fabric covered with 1.7 oz PolyFiber fabric. The landing gear is one piece spring aluminum clamped and bolted directly to the bottom of the fuselage with four bolts. The wheels and tires are 500 x 5 kart type with mechanical drum brakes.
Acrolite 1B
The Acrolite 1B was designed as a good performing entry level aerobatic capable aircraft in a light, low cost package for those pilots that want a more exciting and challenging aircraft to fly than the more common type of light and ultralight aircraft.
Designed by Ron Wilson of Murillo Ontario, it was the winner of the 1995 Scratch Build Design Contest sponsored by Aircraft Spruce and Specialty Co. of Fullerton California and hosted by the Experimental Aircraft Association in Oshkosh Wisconsin. Aircraft Spruce & Speciality became the exclusive supplier of plans and materials packages for the aircraft. Complete construction material packages for the Acrolite (16 total) could be purchased for under $10,000 in 2009. This design won out over 102 entries from all over the world. Aircraft Spruce sponsored the cost of building the airframe and the aircraft was built in one year by Peter Eisenbach of Thunder Bay and Vern Ennis and Harold Spithoff of Kakabeka Falls Ontario. It was designed with strength, ability to take abuse, ease of repair, good short field performance and stable flight characteristics as the most important features. The strut braced staggered wing biplane design affords good visibility and requires a pilot with only average flying ability but with some experience in high performance taildraggers. The design and basic construction is in accordance with standard aircraft practices and aircraft grade materials are used throughout. The aircraft is conservatively stressed for a limit load of 6 G positive and 4 G negative with a 1.5 safety factor at a gross weight of 750 lbs.
Able to be built in a fairly small area, the largest piece is the fuselage which is approximately 12 feet long 2 feet wide and 4 feet high. Built on a 12′ x 2′ table with a minimum of 3 feet of walk around area it can be built in any 17 foot long room. A single car garage is more than adequate and the entire aircraft can be fully assembled in an average 2 car garage. The wing panels are built standing on edge in an 8 foot long jig.
A Rotax 912 the engine was used in the prototype, but the Rotax 582/618 with a “C” or “E” type gear reduction drive will give good aerobatic performance at a lower cost.
The fuselage is constructed of welded 4130 chrome moly steel tube. A welded steel fuselage is generally considered to be the most durable, is easy to repair and provides the best protection against impact damage. Control linkages to the ailerons and elevator are push-pull rods with bearings on each end. Rudder and steerable tailwheel control is via a common cable. The tail assembly is constructed of 6061 aluminum tube riveted together with 2024-T3 aluminum gusset plates.
The wing is of stressed skin wood construction with a built up box section main spar, built up ribs, plywood sheeting and fabric covered. The builder will also have the option of building the wing entirely of 2024-T3 aluminum with a box section main spar, a channel section rear spar, fully sheeted and flush riveted with 1/8 inch diameter stainless steel blind rivets. The airfoil is GA30-212 semi-symmetrical section designed by Harry Ribblett. This airfoil is noted for its low drag and excellent stall characteristics. The ailerons are semi-full span aluminum tube, static balanced. The fuselage, empennage and ailerons are fabric covered with 1.7 oz PolyFiber fabric.
The landing gear is one piece spring aluminum clamped and bolted directly to the bottom of the fuselage with four bolts. This type landing gear has low drag is easy to construct and handles hard landings and rough ground well. The wheels and tires are 500 X 5 aircraft type with cable operated drum brakes. Optionally hydraulic operated disk brakes can also be used. The tailwheel spring is formed from aluminum flat bar and the tailwheel swivel unit is welded from chrome moly sheet steel. The 5 inch diameter tail wheel is molded hi-impact plastic.
Acrolite 1B
Acrolite 1C
The Acrolite 1C is a higher performance version of the Acrolite 1B with the same fuselage and general configuration, but the wing panels have been shortened to eight feet for an 18 foot wing span and a total of 120 sq. ft. of wing area. The horizontal tail volume has been decreased accordingly and the rudder area has been increased. The builder has the option of building the wings of wood or aluminum and of using a GA30U-212 semi-symmetrical section or a GA30U-012 fully symmetrical section for better aerobatic performance when using the higher horsepower engines.
For the best performance the recommended engines are the four cylinder Rotax 80 hp 912 to the 115 hp 914 or the 80 to 120 hp. Hirth F30. Other engines of similar power and installed weight can also be used. The converted Volkswagon engine or the small four cylinder Continental engines are not recommended as the extra weight would cause a weight and balance problem and the power to weight ratio would not be as good.
The aluminum wing is of stressed skin construction with a box section main spar, a channel section rear spar and strut braced. It is built entirely of 2024-T3 aluminum, fully sheeted and flush riveted with 1/8 inch diameter stainless steel blind rivets. The wood wing uses a built up main spar and ribs, is plywood sheeted and fabric covered. The ailerons are full span aluminum tube, static balanced. The fuselage is constructed of welded 4130 chrome moly steel tube. Control linkages to the ailerons and elevator are push-pull rods with bearings on each end. Rudder and steerable tailwheel control is via a common cable. The tail assembly is constructed of 6061 aluminum tube riveted together with 2024-T3 aluminum gusset plates. The fuselage, empennage and ailerons are fabric covered with 1.7 oz Polyfiber fabric. The landing gear is one piece spring aluminum clamped and bolted directly to the bottom of the fuselage with four bolts. The wheels and tires are 500 x 5 aircraft type. Due to the higher output engines hydraulic operated disk brakes are recommended.
The aircraft is conservatively stressed for a limit load of 6 G positive and 4 G negative with a 1.5 safety factor at a flying weight of 750 lbs.
The Acrolite 1C prototype had a 150 hp snowmobile engine, detuned to 120 hp and a new experimental reduction drive. The intent is to test the airframe performance with very high power to weight ratio (less than 6 lb per hp).
Acrolite 1C
Acrolite Engine: Rotax 447, 40 hp Empty Weight: 281 lb Wing span: 22 ft
Acrolite 1A Engine: Rotax 447, 40 hp Reduction: 2.58 to 1 Propeller: 62 x 32 Airfoil: NACA 4412 Wingspan: 22 ft Wing area: 140 sq.ft Wing Chord: 3.5 ft Aspect ratio: 6.3 to 1 Length: 16 ft Height: 5.75 ft Fuel capacity: 5 UGS Wheel & tire size: 500 x 5 Empty weight: 280 lb Gross weight: 500 lb Wing loading: 3.6 lb./sq.ft Power loading: 12.5 lb/hp Power off stall speed: 32 mph Power on stall speed: 30 mph Landing speed: 37 mph Maneuvering speed: 65 mph Maximum level speed: 70 mph Never exceed speed: 80 mph Cruise speed: 65 mph @ 5000 rpm Best glide speed: 50 mph Best rate of climb: 800 fpm Best climb rate speed: 50 mph Best climb angle speed: 48 mph Range: 100 sm Take off distance: 300 ft Landing distance: 200 ft Seats: 1
Engine: 45 hp Rotax 503 Reduction: 2.58 to 1 Propeller: 63 x 36 Airfoil: NACA 4412 Wingspan: 22 ft Wing area: 140 sq.ft Wing Chord: 3.5 ft Aspect ratio: 6.3 to 1 Length: 16 ft Height: 5.75 ft Fuel capacity: 5 USG Wheel & tire size: 500 x 5 Empty weight: 280 lb Gross weight: 500 lb Wing loading: 3.6 lb/sq.ft Power loading: 11.1 lb/hp Power off stall speed: 32 mph Power on stall speed: 30 mph Landing speed: 37 mph Maneuvering speed: 65 mph Maximum level speed: 72 mph Never exceed speed: 80 mph Cruise speed: 66 mph Best glide speed: 50 mph Best rate of climb: 1000 fpm Best climb rate speed: 55 mph Best climb angle speed: 48 mph Range: 100 sm Take off distance: 250 ft Landing distance: 200 ft Seats: 1
Acrolite 1B Engine: 80 hp Rotax 912 Reduction: 2.43 to 1 Propeller: 68 x 48 Airfoil: GA30U-212 Wingspan: 20 ft x 2 Wing area: 133 sq. ft. Aspect ratio: 9 to 1 Length: 17 ft. Height: 6 ft. Fuel capacity: 9 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 500 lbs Gross weight: 800 lbs Span loading: 20.0 lb/ft Wing loading: 6.0 lb/sq. ft. Power loading: 10 lb/bhp Power off stall speed: 45 mph Power on stall speed: 40 mph Landing speed: 55 mph Maneuvering speed: 85 mph Maximum level speed: 130 mph Never exceed speed: 150 mph Cruise speed@ 5000 rpm: 110 mph. Best glide speed: 75 mph Best rate of climb: 1800 fpm Best climb rate speed: 80 mph Best climb angle speed: 70 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
Engine: 75 hp Rotax 618 Reduction: 2.58 to 1 Propeller: 66 x 46 Airfoil: GA30U-212 Wingspan: 20 ft. x 2 Wing area: 133 sq. ft. Aspect ratio: 9 to 1 Length: 17 ft. Height: 6 ft. Fuel capacity: 9 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 480 lbs Gross weight: 750 lbs Span loading: 18.7 lb./ft Wing loading: 5.6 lb./sq. ft. Power loading: 10 lb/bhp Power off stall speed: 42 mph. Power on stall speed: 38 mph Landing speed: 53 mph Maneuvering speed: 85 mph Maximum level speed: 125 mph Never exceed speed: 150 mph Cruise speed@ 5600: 105 mph. Best glide speed: 75 mph Best rate of climb: 1900 fpm Best climb rate speed: 80 mph Best climb angle speed: 70 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
Engine: 65 hp Rotax 582 Reduction: 2.58 to 1 Propeller: 64 x 44 Airfoil: GA30U-212 Wingspan: 20 ft. x 2 Wing area: 133 sq. ft. Aspect ratio: 9 to 1 Length: 17 ft. Height: 6 ft. Fuel capacity: 9 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 480 lbs Gross weight: 750 lbs Span loading: 18.7 lb./ft Wing loading: 5.6 lb/sq. ft. Power loading: 11.5 lb/bhp Power off stall speed: 42 mph. Power on stall speed: 38 mph Landing speed: 53 mph Maneuvering speed: 85 mph Maximum level speed: 110 mph Never exceed speed: 150 mph Cruise speed: 90 mph Best glide speed: 75 mph Best rate of climb: 1400 fpm Best climb rate speed: 80 mph Best climb angle speed: 70 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
Acrolite 1C Engine: Rotax 912U, 80 hp Reduction: 2.27 to 1 Propeller: 65 x 55 Airfoil: GA30U-212 Wingspan: 18 ft. x 2 Wing area: 120 sq.ft Aspect ratio: 8 to 1 Length: 17 ft Height: 6 ft Fuel capacity: 9 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 525 lb Gross weight: 800 lb Span loading: 22 lb/ft Wing loading: 6.7 lb/sq.ft Power loading: 10 lb/bhp Power off stall speed: 48 mph Power on stall speed: 44 mph Landing speed: 65 mph Maneuvering speed: 95 mph Maximum level speed: 130 mph Never exceed speed: 160 mph Cruise speed: 112 mph Best glide speed: 75 mph Best rate of climb: 1600 fpm Best climb rate speed: 80 mph Best climb angle speed: 70 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
Engine: Rotax 912S, 100 hp Reduction: 2.43 to 1 Propeller: 68 x 64 Airfoil: GA30U-212 Wingspan: 18 ft. x 2 Wing area: 120 sq.ft Aspect ratio: 8 to 1 Length: 17 ft Height: 6 ft Fuel capacity: 9 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 525 lb Gross weight: 800 lb Span loading: 22 lb/ft Wing loading: 6.7 lb/sq.ft Power loading: 8 lb/bhp Power off stall speed: 48 mph Power on stall speed: 44 mph Landing speed: 65 mph Maneuvering speed: 95 mph Maximum level speed: 140 mph Never exceed speed: 160 mph Cruise speed: 122 mph Best glide speed: 75 mph Best rate of climb: 2100 fpm Best climb rate speed: 90 mph Best climb angle speed: 70 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
Engine: 120 hp Hirth F30 Reduction: 2.43 to 1 Propeller: 64 x 44 Airfoil: GA30U-012 Wingspan: 18 ft. x 2 Wing area: 120 sq.ft Aspect ratio: 8 to 1 Length: 17 ft Height: 6 ft Fuel capacity: 9 gal U.S. Wheel & tire size: 500 x 5 Empty weight: 525 lb Gross weight: 800 lb Span loading: 22 lb/ft Wing loading: 6.7 lb/sq.ft Power loading: 6.7 lb/bhp Power off stall speed: 48 mph Power on stall speed: 44 mph Landing speed: 65 mph Maneuvering speed: 95 mph Maximum level speed: 150 mph Never exceed speed: 160 mph Cruise speed: 130 mph Best glide speed: 75 mph Best rate of climb: 2400 fpm Best climb rate speed: 90 mph Best climb angle speed: 70 mph Range: 250 sm Take off distance: 500 ft Landing distance: 500 ft
Designed by Edward Stalker (University of Michigan) and first built in 1928, the Model 21 was a 2 place, open cockpit, high wing monoplane, with folding wings. First flying on 2 October 1929, two were built (NX152E & N13622) with Velie engines, but N13622 was later repowered with a 100hp Kinner K-5 and was rechristened by its owner as Smith O. NX152E is also noted in registers as Para-monoplane
Designed by Ron Beattie and Walt Fellers, two North American Engineers who came to work for the Northrop Division, the 1948 Acme Sierra (a.k.a. “Sierra Sue”) N12K was built by the Acme Aircraft Co. at the Torrance Airport in late 1948. It was built by Acme’s Crawford and Keeney.
Designed and flown by Ron Beattie and Walt Fellers, the first flight took place on 23 November 1953. It was built according to Goodyear Racing Plane specifications. Although it was never entered in any races, extensive data was obtained during its many flights.
It was built to investigate the advantages of a pusher propeller configuration. It has a “Y” shaped tail incorporating ruddervators on the upper fins, an unswept wing mounted midway up the fuselage, an engine mounted directly behind the cockpit, and large air scoops mounted in the forward end of both wing roots. The aircraft, now designated as the Sierradyne S-1, was used by Sierradyne Inc. in the 1960’s to test and promote Northrop’s and Dr Werner Pfenninger’s boundary layer control concepts. Northrop used it as a flying technology demonstrator for the Air Force’s AX close-support aircraft design competition in 1972, but despite its being re-labeled as the Northrop Turbo-Pusher, the plane was never officially considered a Northrop aircraft.
It is reported displayed at the Los Angeles Science Museum.
After finishing the Star*Kraft, Jeff Ackland went on to design and build the Legend. Martin Hollmann helped Ackland at the beginning of the design. First flown in June 1996, the aircraft is designed for aerobatics at full gross weight. After a successful debut at Oshkosh 1996, Performance aircraft announced kit production.
The prototype two-seat tandem Legend was powered by a 575 hp, 620 cu.in Chevy based aluminium V-8 engine using a Geschwender chain drive propeller speed reduction unit turning a three blade, constant speed Hartzell prop. Jeff Ackland claims the airframe can go up to 1000hp.
Construction is with vacuum-bagged prepreg carbon fibre composites with honeycomb cores. A wide stance retractable tricycle undercarriage and laminar flow wing with electrically actuated slotted Fowler flaps allow more manageable landings. Ackland claims an honest 2500 hrs is required to build the legend. An extended wing became an option.
The kit price in 1996 was US$78,500, not including engine, prop, PSRU, instruments, avionics, paint or upholstery. Total build cost was estimated to be US$150,000.
Engine: Chevrolet 620ci, 575 hp Cruise: 400 mph Vne: 500 mph Empty weight: 2100 lb MAUW: 3000 lb Useful load: 1000 lb Cockpit width: 30 in
Engine: Chev 541 ci, 600 hp Hp range: 400-1000 Wingspan (extended wing): 28.5 ft Wing area: 100 sq.ft Length: 25 ft Height: 8.7 ft Empty wt: 2000 lb MAUW: 3000 lb Fuel cap: 125 USG Top speed: 376 mph Cruise: 362 mph Range: 1500 sm Rate of climb: 5500 fpm TO dist: 800 ft Ldg dist: 1000 ft Service ceiling: 25,000 ft Seats: 2 Undercarriage: retract/nosewheel
