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Piuma Twin Evolution

Author preliminary remark

The Piuma Twin project was completed in 1998.

At the time of this update, two Piuma Twins are flying and about 12 are in construction in various parts of the world. Many improvements and changes have been made in recent years, which has suggested the redoing of almost all of the drawings.

Twin Evolution project information

The Piuma Twin Evolution incorporates all the improvements suggested during 9 years of Piuma Twin construction, with the front of the fuselage stretched 20 cm, for a better balance for 2 people without the need for ballast and an aft shape similar to the single seat Piuma Evolution. This shape lightens the aft parts and stiffens the tail boom. The elevators are similar to the single seat Piuma Evolution.

Some of the control linkages have been simplified. The wood fuselage has been lightened. The instruments panel now is similar to a glider's. The engine mount is improved.

There is a single version, instead of 3, more compatible with the project philosophy. The wing span increased to 42.7 feet and the wing area increased to 132 sq. ft.

Special drawings # 12sp, 13sp and 14sp are available, to allow the construction of wing spans from 42 to 45 feet, with high efficiency winglets, and some other possibilities.

It's recommended to use a light engine, considering it's position behind the center of lift. It is best not to exceed 122 lbs for engine, mount and propeller.

A Rotax 503, with 1:2,58 PSRU and electric system (45/50 Hp), combined with a carbon fiber, 62", 3 bladed prop, could be suitable, sufficient power and low fuel consumption. The HKS, 4 stroke – 60 Hp could be a real goal. A little more weight, but 40 % less fuel consumption than the 503, with the possibility of a smaller fuel tank and less fuel weight. The 503 has been replaced by the 582.

Flight comfort is very important, because the Piuma Twin Evolution is designed to travel. The two seat cockpit is 43" wide and the ergonomic seats are very comfortable and well padded.

The pilot position is similar to a comfortable car, with the centrally mounted control stick in place of the gear-lever and the rudder-bars in place of the clutch-brake pedals. The throttle and spoiler controls are to the left of the pilot.

Technical information

Wing Span
Wing Area
Length
Height
Empty Weight
Gross Weight
Fuel Capacity
HP/HP Range
V.N.E.
Top speed
V.A.
Stall clean
Stall full flaps
L/D
Min. Sink Rate
Load factors max.
Bldg Material
Bldg Time (man hours)
Take-off distance
Landing distance
42.7 ft.
132 sq.ft.
21.3 ft.
5.6 ft.
600 lbs.
980 lbs.
11 Imp gal
45/60
106 mph.
103 mph.
92 mph.
44 mph.
35 mph.
20/1
220 ft/min.
+ 4.6 -2.3
WF
1.000
400 ft.
400 ft.

Drawings list

The latest version, has 16 large 24” x 41” sheets, with all details full size:
  • #. 1 to 6 Triptych, fuselage, frames, landing gears, controls, engine mount, etc
  • #. 7 to 11 Wings, ribs, spars, controls in the wings, ailerons, flaps and spoilers
  • #. 15 to 19 Vertical stabilizer, Elevator, ribs and spars, controls and aft little wheel

The special drawings #. 12sp, 13sp and 14sp are optional. They include increasing the wing span from 42 to 45 feet with high efficiency winglets, covering the wings with birch ply, putting the fuel tanks in the wings and building new special spoilers.

Construction plans

The Basic Plans are composed of 16 sheets in English and the Construction Book in English (44 pages with 30 photos and many sketches to explain the construction); a complete materials list is also included.

There are instructions to determine the weight and balance and detailed instructions on how to prepare for first flight; there is also a list of the weight of components.

In the Advanced Plans, there are the 3 optional sheets, the Project book (this is in Italian , but there are 32 photos and 80 drawings, graphics and lists. It is easy to understand the calculations) and a DVD with 3200 photos (1600 are of the Twin construction).

The tail boom of 6005-T16 Aluminum alloy is available from the designer: diameter 127mm - thickness 1.5mm - lenght 5.2.m.

The Twin needs the 5.2m pipe and an additional piece 2.6m long.

The wing airfoils are the same as the Tourer Piuma.

The material cost, without engine and instruments, is about 5.500 euro, at the 2017 prices.

The time of construction is about 1000 hours.

Requests continue to be received for comments regarding a video posted on YouTube in 2008 by Mr Luca Baldi following the test flight of its Piuma Twin ended with a disastrous landing in a plowed field with the consequent destruction of the motorglider (pilot uninjured).

Here is available the report compiled in those days, so that anyone can have an opinion about.

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