The ultralight motorglider Piuma appeared in 1989 because the designer and builder was looking for a safe ULM motorglider, easy to build and to pilot, whose flight and comfort was better than the “fabric and tube” ULM available at the time.
The Original Piuma first flew in 1990 and the project changed and the plans were modified with improvements. The Original Piuma is the more quiet version and the more suitable as first construction. The steel landing gear, with rubbers shock-absorbers, also allows the beginners hard landing. The 2005 plans allow to build the streering front gear. This improvement also allowed to increase the top speed of 5 km/h (3 mph).
ULM single seat motorglider made of fabrics and wood, only the tail pipe in aluminium alloy and propulsive engine. The maximum wing loading is 4.3 lb/sq.ft; this low wing loading allows the motorglider to fly at low stall and landing speeds. The glide ratio is about 16 – 17 and the minimum sink rate is 200 ft/min.; it is possible to use a little 25 HP engine with very low consumption (1 Imp Gal/h). The stall speed is 30 MPH and the take-off speed is normally 34 MPH, but it is possible also 29 MPH, for the ground effect. The normal cruising speed is 50 MPH and the VNE is 75 MPH.
Construction characteristics
Conventional 3 axis control with air-brakes.
The wings are tapered; the chord at root is 47,2 inches and at tip is 21,6 inches.
The wing profile is the Rhode St. Genese 36, with the 16% thickness.
The landing gear is built with the Cr-Mb steel, with the rubbers shock-absorbers, and it is put very near (but in front of) the C of G. The wheels have brakes and fairings. The nose wheel has no steering and shock-absorber.
The little tail wheel and the rudder are steerable at the same time; this special shape unites the advantages of the classic three wheel in tricycle formation take-off and landing and the good ground characteristic of the tail-dragger formation.
The instruments panel is big enough for a complete set of instruments. The fuel-tank can contain more than 4 Imp Gal. and it is sufficient for 4 fly-hours (or much more of soaring).
The plans have been improved compared with the prototype (that has flown very well since the 1990).
They are available, with notes in English and with a new construction handbook in English of 39 pages, with more of 50 photos and some little draws for the explanation.
Also the tail boom is available: diameter 127 mm – thickness 1,5 mm – length 5,2 m.
The complete material list is in the handbook (birch plywood, spruce, aluminium, steel, fabric, etc.).
The material cost, without engine and instruments, was about 6000 euro, at the 2007 prices.
Since 2003 the original Piuma plans allow nosewheel steering.
The Piuma Evolution is different from the Original Piuma in the following modifications:
Fuselage shape: the cockpit is 1 inch more wide. The rear side is completely tapered and the lower side is rounded for better attractiveness and aerodynamic.
Wing shape: the chord at root is 43,3 inches (the original is 47,2 inches) and the aspect ratio is 13/1 (original 11,2/1). Dihedral is 2 degrees instead of 3 degrees and the wing profile changes from 16% into 15%. Max thickness.
Tail shape: the tail and fin area now are more little and slimmer; the tail is cantilever, with 2 little strut drops. The 8 steel cables used in the Original Piuma were removed.
Wing struts: now the wing struts are smaller and they are aluminium-alloy.
Engine: the engine is partially hidden by the wings in the Original Piuma; now it is in the full air and it is possible to use the engine at the full power for longer.
Front wheel: now it is electrically retrectable; it is also possible to build it fixed and with fairing, steering too.
Landing gear: the wood landing gear covered with epoxy glass (or epoxy carbon fiber) is much more aerodynamic.
Seat: it is shaped for a more outstretched position, right for a glider. It is more comfortable and also suitable for 6 feet tall pilots (or little more).
Instrument panel: it is more similar to a glider panel.
Tail trim: it is electrical; the construction is clearly drawn in the plans.
Aerodynamic brakes: the controls and have been improved and drawn in 1 to 1 scale.
The best efficiency now is 20 and the normal cruise is about 63 MPH at 80% power with a 25HP engine.
The estimated building time is 1000 hours, the same of the Original Piuma.
Evolution Piuma (a little faster and more suitable for soaring, with a best glide ratio of 20) and Tourer Piuma (it’s the faster version for tourism, normal cruise 84 mph) became available.
The Italian C.A.P. (E.A.A. chapter n. 459) gave two prizes for the best ultralight project and the best achivement during the Carpi meeting of 1997 and 1999 (prize “Giancarlo Maestri” and “Caproni Cup”).
It is also possible to build two stronger versions of the one seat Piuma, for heavier pilots:
Rotax 447 Evolution Piuma (max take-off weight 660 lbs)
Rotax 447 Tourer Piuma (max take-off weight 660 lbs)
Plans only are sold.
All the “Piuma” versions are designed in accordance with the aeronautical standard and, for both the one seat Piuma and the Piuma Twin, the “project books” are available (only in Italian, at the moment). Every “project book” is composed of three parts:
The motivations of the choices about the shapes (wings, fin, rudder and elevators, fuselage with the rear engine mounting, etc.) with a lot of draws showing the fuselage, wings, tail, etc.
Structural calculations.
Characteristics of fly, wing and total drag, wing lift, efficiency, Vx, Vy, VNE, Vstall, etc.
The plans are composed of technical drawings of big dimensions (24 x 40 inches).
Some details must be realized with the lathe and the cutter, but almost the entire construction may be built without special tools; it is very easy and the planner completed the original Piuma after 18 months of work, in the 2 car garages, 7 yards long and 4,4 yards wide.
Normally about 1000 hours are sufficient to complete construction.
The wings, fin, rudder and elevators ribs are drawn in 1 to 1 scale; the same scale is used for a lot of wood or aluminium details. The handbook describes the work the step by step and the check list for the pre-fly controls.
About 30 minutes are sufficient to assemble or disassemble the Piuma.
The Piuma Evolution construction plans are composed of 15 drawings with references in Italian and english and a handbook in Italian language (35 pages) or English (25 pages). These books contain a lot of photos and little drawings and the materials list.
Also the tail boom is available: diameter 127 mm – thickness 1,5 mm – length 5,2 m.
The material cost, without engine and instruments, is about 6000 euro, at the 2007 prices.
The time of construction is about 1000 hours.
The Piuma Tourer is the fast version. The basic information about the fuselage and the tail is the same as the Piuma Evolution.
The only difference between the “fast version” and the Piuma Evolution is the wing with less span and area and with two different profiles.
Changes in comparison with the Piuma Evolution are:
WING profile: NACA 4415 (for the rectangular wing area); NACA 2R1-12 (for the tip – sweepback 3degrees)
Wing areas: change from 114,1 sq.ft into 99 sq.ft (wing loading = 5,5 lb/sq.ft)
Wing span: change from 38,7 ft into 34,1 ft; the aspect ratio is 11,7
Tailplane balancing
Change of the wing connection point for the strut
Spar thickness increase
Max take-off increase to 550 lbs
On request it is possible to build the Rotax 447 Tourer Piuma Version (max take-off weght 660 lbs).
The plans are the same 15 drawings of Piuma Evolution with one big drawing more showing:
The 9 ribs profiles.
The new wing design.
The new spar.
The tailplane balancing system.
The material cost, without engine and instruments, is about 6000 euro, at the 2007 prices.
Original
Wing span: 38.4 ft
Total wing area: 125 sq.ft
Aspect ratio: 11.2
Dihedral: 3 degrees
Total tailplane area: 17.2 sq.ft
Tail arm: 10.7 ft
Length overall: 19.4 ft
Max height: 4.6 ft
Empty weight: 320 lb
Max take-off weight: 518 lb
Max wing loading: 4.14 lb/sq.ft
Recommended load factors: + 3.4 -1.2
Ultimate load factors: + 6.8 – 2.5
Max level speed: 59 MPH
Normal cruising speed: 50 MPH
Stalling speed: 30 MPH
Never exceed speed: 75 MPH
Best glide ratio with power off: 17
Take-off: 330 ft
Landing: 330 ft
Max climb rate at sea level: 390 ft/min
Min sink rate (at 36 MPH): 200 ft/min
Engine: 25 HP
Piuma Evolution
Wing span: 38,7 ft
Total wing area : 114 sq.ft
Aspect ratio: 13
Dihedral: 2 degrees
Total tailplane area: 15 sq.ft
Tail arm: 10,8 ft
Length overall: 19,7 ft
Max height: 5,3 ft
Empty weight: 330 lb
Max take-off weight: 530 lb
Max wing loading: 4,6 lb/sq.ft
Recommended load factors: + 3.5 – 1.9
Ultimate load factors: + 7 – 3.8
Max level speed: 72 MPH
Normal cruising speed: 62 MPH
Stalling speed: 35 MPH
Never exceed speed: 84 MPH
Best glide ratio (at 43 MPH): 20
Take-off: 330 ft
Landing: 330 ft
Max climb rate at sea level: 460 ft/min
Min sink rate (at 39 MPH): 165 ft/min
Engine: 25 HP
Tourer
Max level speed (with 35 hp engine): 93 mph
Normal cruising speed: 84 mph (glide ratio = 10)
Never exceed speed: 100 mph
Stalling speed: 39 mph
Max climb rate at sea level: 1000 ft/min
Min sink rate (at 42 mph): 235 ft/min
Best glide ratio (47mph): 17
