The Airplanes and Gliders of Adriano Mantelli
The Airplanes and Gliders of Adriano Mantelli
by Giuseppe Blini
In the international and Italian aviation panorama few
are the people who sum up in themselves the gifts of an ace fighter pilot, test
pilot, record-setting man and designer and builder of aircraft.
Several articles have already been written about him. One
appeared on the pages of this magazine about thirty years ago. After so long,
we thought it would be interesting to bring to the attention of today’s readers
Adriano Mantelli’s activity as a designer and builder of aircraft, in parallel
with his brilliant military and sport aviation career.
It is not really important if none, or almost none, of
Mantelli’s creations enjoyed much commercial success; they were all very
interesting from a technical point of view, and the fruits of a wide-ranging
activity that only a very competent, passionate and determined person could
have realized.
I have a particularly fond memory of Mantelli when, on
the occasion of his test flights of the Procaer F15E at Malpensa, I met him and
I talked to him about the Club Aviazione Popolare (an Italian aircraft
homebuilder association) that was being formed at the time, and he joined our
enterprise enthusiastically.
A Short Biography of Adriano Mantelli
Adriano Mantelli was born in Cortile San Martino (Parma)
on February 13, 1913. He grew up in the San Leonardo neighborhood and studied
at the “Paolo Toschi” Regio Istituto d’Arte (Italian Royal Art Institute).
At age 15, his great passion for aviation led him to
found a company (S.D.A.M.) with his cousin Dino Sirocchi, which initially built
only flying aircraft models but later went on to build true gliders. Having to
test-fly real aircraft, Mantelli sought training at the Cantù flight school,
that he reached with his bicycle from Parma (about 105 miles).
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| A young Adriano Mantelli launching a rubber-powered model |
The War Years
After graduation,
Adriano Mantelli joined the Regia Aeronautica (the Royal Italian Air Force),
first as a non-commission officer and later transited to permanent service. At
the outbreak of the Spanish Civil War, he was sent to Spain with the Aviazione
Legionaria. In Spain he distinguished himself with his FIAT C.R.32 fighter,
scoring several victories in aerial combat.
After his return to Italy, his work was divided between
flying for the Regia Aeronautica and an intense soaring competition activity in
which he set several Italian records and won important national races. Thanks
to his fame and his expertise he became one of the three pilots entrusted to
select the type of sailplane to be used in the planned 1940 Olympics.
At the outbreak of WWII, Adriano Mantelli was a test
pilot at the Centro Sperimentale (Experimental Flight Base) in Guidonia (near
Rome), where he was soon promoted to the rank of captain. Thereafter followed a
period during which Mantelli worked as a test pilot for the development of new
aircraft at the I.M.A.M. (Industrie Meccaniche Aeronautiche Meridionali)
company in Naples.
After the September 8,
1943 Armistice, he was reunited with his family and joined the A.N.R.
(Republican Air Force) where he carried on his test pilot work and served as a
flight instructor. (He was the pilot who tested the torpedo carrying version of
the F.I.A.T. G.55.) In 1944, he managed to restart the military glider
specialty, setting up an autonomous squadron based in Cascina Costa (Samarate,
Varese), home of the Agusta company. The glider squadron operated until the end
of the war.
In the immediate post-war period, Adriano Mantelli was
“expurgated” for having joined the A.N.R. and expelled from the air force. But
he continued designing and building aircraft; and, with Livio Agostini, owner
of a bicycle manufacturing company, he founded a new company named ALAPARMA.
In 1949, invited by the government of Argentina, Mantelli
moved to South America followed by his family. In Argentina, he found
employment as a flight instructor at the Club de Planeadores Albatros in Merlo
(Greater Buenos Aires area). During the three years that he spent in Argentina,
he designed and built several aircraft and set a few Argentine sailplane
records.
After he returned to Italy in 1951, Mantelli was
reintegrated into the Italian Air Force and was charged with setting up the
Centro Militare di Volo a Vela (Military Soaring Center), first at the Rome
Urbe airport and later in Guidonia. The following year, he competed in the
Soaring World Cup competition in Spain.
In 1953, ha was appointed by the Italian Air Force and
the Aeroclub of Italy to create the Centro Volovelistico (National Soaring
Center) of Rieti which trained flight instructors for the reviving Italian
soaring activity. In the following years, Mantelli participated in other world
championship competitions and conquered other important sailplane records, for
example the 28-hour endurance record for two-seaters, established with a C.V.V.
6 Canguro sailplane.
His activity continued at the Guidonia military soaring
center, where he continued to design, build and modify several sailplanes that
went on to set other records (too many to list here).
Mantelli finally retired from the Air Force in 1971, with
the rank of Generale di Brigata Aerea (Brigadier General) of the Reserve.
He died in Florence at the age
of 83, during a trip to a meeting of the Italian Pioneers of Flight
Association.
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| A drawing that Mantelli made for his grandson, which shows all Mantelli's designs throughout the years |
The gliders, motor-gliders and light airplanes born from
Adriano Mantelli’s mind were many, even though most of them remained at the
prototype stage and were never built in series; except the AM.10 (otherwise
known as ALAPARMA Baldo 75), a small number of which were built thanks to a
ministerial subsidy.
After so many years, a lot of information was lost or
became confused. We will try to examine all the designs one by one and date
them. We will attempt to identify their characteristics and relate all the
information about them as best as we can.
The most evident architecture peculiarities, common to
all Adriano Mantelli’s machines, were the relatively small size, simple wooden
construction, lightness and aerodynamic finesse. The result was relatively
inexpensive aircraft of high performance, considering the low power of their
engines.
With a few exceptions the typical architecture of
Mantelli’s aircraft consisted of a compact airframe, with the wing forming a
single block with the cabin, the tail empennage supported by twin tail booms
that were usually foldable, to facilitate towing and transportation, a
propulsive (pusher) engine, a single-track landing gear with a tailwheel, and
stabilizing small wheels placed at mid wingspan.
A good starting point would be the drawing that Adriano
Mantelli made for his grandson (shown above). But we tried to list also all the
designs that were not realized. All the models are listed in order of
denomination, which does not always correspond to the chronological order.
It is important to underline how prolific Mantelli was,
considering that all the designs were made in a relatively short time and in a
very difficult social and economic situation.
AMVTE 1927
Glider Adriano Mantelli designed at
the age of 15. The dimensions are unknown.
AM.1 “Me ne frego” 1932
Single seat glider built by the SDAM
group (Sirocchi Dino – Adriano Mantelli). Similar in shape to the German
Zoegling glider, with a few improvements to the wing spars. It was later
endowed with an aerodynamic fairing for the pilot place, which considerably
improved its performance.
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| AM.1 "Me ne frego!" |
AM.F1 1933
Designed by Mantelli and built by Enzo Fossa, with the
collaboration of the Federazione dei Fasci Giovanili di Parma (Parma Young
Fascist Federation). It was a wooden glider, with a trellis fuselage covered
with fabric, a rectangular plan, fabric covered wing braced by V struts.
Registered with number 170, the glider was successfully tested by Mantelli and
took part in the Littoriali di Volo a Vela, a gliding competition held in
Cantù.
Mantelli made the first winch launches of glider in
Italy, with a winch he himself had designed.
Technical data:
Wingspan: 11 m (36 ft)
Length: 5,70 m (18.7 ft)
Height: 1,50 m (4.9 ft)
Wing Area: 16.5 m ² (177.6 sq ft)
Empty weight: 95 kg (209.4 lb.)
Gross weight: 170 kg (374.7 lb.)
Glide ratio: 16
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| AM.F1 |
AM.5 1938
Aerobatic single-seat glider design, inspired by the
German Habicht type. Wooden construction, mid wing with large surface ailerons
and relatively short fuselage. A model was tested in the Guidonia wind tunnel,
but the aircraft was not built. The dimensions and the projected performance of
the AM.5 are also unknown.
AM.6 “La Gallina” (The
Hen) 1939
It was the first powered aircraft designed by Adriano
Mantelli. The AM.6 differs from most following Mantelli’s designs in having a
“conventional” configuration. The use of an 18 CV (17.7 hp) Kohele engine was
envisioned, but the airplane was not built. All the dimensions are not known,
except:
Wingspan: 7 m (22.9 ft)
Length: 4,90 m (16 ft)
AM.6 “Bitrave” (Twin
Tail boom) 1940
The AM.6 can be considered the architectural precursor of
the majority of Adriano Mantelli’s designs.
It was built in Naples, during the time Mantelli was
assigned to test-fly the new aircraft produced by I.M.A.M., such as the Ro.58,
and tasked with the acceptance of series-built airplanes. The AM.6 was built in
a house basement with the collaboration of Gennaro Scognamiglio, an I.M.A.M.
technician. The design phase also included wind tunnel tests, carried out by
Dr. Preti at the Politecnico of Milan.
The AM.6 was a true airplane, but it was classified as a
motor-glider, to simplify the bureaucratic process in view of its possible
certification. It was of wooden construction, like all of Mantelli’s aircraft.
The planform of the cantilever wing was rectangular with
rounded wing tips. The structure of the wing featured a single spar with a
box-like leading edge covered with plywood. The surface of the wing aft of the
spar was covered with canvas. The wing was equipped with flaps, and
conventional ailerons.
The structure of the fuselage was a wooden shell, with
spruce stringers covered with plywood. Thanks to the shrewdness of the design
of the wing joints the frontal section of the aircraft was reduced, to the
benefit of performance, notwithstanding the low power of the engine.
The fabric covered tail empennage was supported by two
box-framed booms, joint to the main wing spar.
The landing gear had a single central wheel, like that of
a glider. The belly of the airplane was protected by a skid. There is no
precise information about the use of lateral wing-mounted stabilizing small
wheels.
The engine was a motorcycle-derived 18 CV (17.7 hp) at
4000 rpm Aubier & Dunn driving the propeller through a chain reduction
gear. That was the same engine installed by Henry Mignet on his famous “Pou du
Ciel.”
The propeller, developed by Dr. Ferri in Guidonia and
made by Otello Bucarelli of AVIA in Vercelli, could maintain constant rpm
through the eccentric linkage of its two blades (this system was also used
after the war by the Aeromatic propellers). The author had the pleasure to meet
Otello Bucarelli, who told him how he got the idea of the skew linkage of the
propeller blades by folding a paper on a tramway car.
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| The eccentric Bucarelli constant-speed propeller |
The first successful test of the AM.6 took place at
Capodichino (Naples) in 1942. However, the Allied bombing convinced Adriano
Mantelli to move the airplane to a safer place. The AM.6 was transferred to the
Centro Volovelistico (Sailplane Flying Center) of Sezze Romano (Latina).
Unfortunately, in the disaster that followed the
September 8, 1943 Armistice all traces of this very interesting airplane were
lost. There remain only a few blueprints and some photographs in the Mantelli
family’s archive.
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| The AM.6 in a dark lively |
Wingspan: 6.28 m (20.6 ft)
Length: 4.10 m (13.4 ft)
Height: 1.40 m (4.5 ft)
Wing area: 6 m² (64.5 sq ft)
Empty weight: 115 kg (253.5 lb.)
Gross weight: 200 kg (440.9 lb.)
Max. Airspeed: 152 km/h (82 kts.)
Cruise speed: 130 km/h (70 kts.)
Min. Airspeed (with flaps): 50 km/h
(27 kts.)
Range: 650 km (350 NM)
 |
| The wing of an AM.6 without the canvas covering. Four Macchi C.200 in the background. |
AM.6 “Monotrave” (Single Tail Boom) 1957
Post War project. It was a single seat motorglider
derived from the AM.6 Bitrave of which it preserved the wing.
The tail boom consisted of an aluminum alloy tube that supported the wooden
canvas covered V tail. The shape of the fuselage, the monowheel landing gear
and the belly skid were similar to its predecessor’s.
The engine was an automotive derived Volkswagen engine,
placed in the bottom of the fuselage and driving a wooden fixed pitch propeller
through an rpm reduction gear.
One example of the AM.6 was completed in Parma and made
only one flight as a glider towed by an MB.308. This aircraft was exhibited at
the Caproni Museum in Vizzola Ticino (Varese), and was later moved to Trento.
The design performance and the dimensions are unknown,
except:
Wingspan: 6.28 m (20.6 ft)
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| Two images of the Monotrave |
AM.7 1943
This single seat motorglider did not proceed beyond the
design phase.
Wooden construction. It maintained the general structural
architecture of the AM.6 Bitrave, with the difference that the wing was
tapered, equipped with large flaps, and mounted in a mid-fuselage position.
The envisioned engine was a 38 CV (37.4 hp) two-cylinder
CAN C II driving a pusher two-blade fixed pitch propeller.
Technical data
Wingspan: 6.6 m (21.6 ft)
Length: 4.4 m (14.4 ft)
Height: m 1.8 (5.9 ft)
Wing area: 7 m² (75.3 sq ft)
Take off weight: 200 kg (440 lbs.)
AM.8 “Luì” 1946
It was the first two-seat aircraft
designed by Mantelli with the scarce resources of the newly constituted
ALAPARMA, and it was classified as a “velivolo sportivo” (Sport Aircraft). It
reproposed the tapered wing of the AM.7, with a larger fuselage to allow for
the heavier weight of the two-seat configuration.
The frame was completely made of wood,
covered with fabric, with a single-track landing gear and wing-mounted
stabilizer wheels. There was a single vertical empennage, mounted in a central
position on the horizontal stabilizer.
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| A partially covered Luì |
The back-to-back accommodation of
the pilot and the passenger was very unconventional, for balancing purposes.
Presumably, the total weight of the crew was very low, considering the declared
gross weight of the aircraft.
 |
| AM.8 Luì |
The engine initially installed was the 38 CV (37.4 hp) CNA C II salvaged from Stefanutti’s canard SS2 motorglider, driving a fixed pitch pusher propeller. The AM.8 was also tested with the two-cylinder 19 CV (18.7 hp) Ermanno Bazzocchi’s MB.2 engine derived from the AerMacchi three-wheel truck’s unit.
It is almost incredible that the aircraft could
fly well on that power and with a direct-drive propeller.
 |
| AM.8 Luì from the rear |
Technical data:
Wingspan: 7 m (22.9 ft)
Length: 5 m (16.4 ft)
Wing area: 8 m ² (86.1 sq ft)
Empty weight: 100 kg (220 lbs.)
Gross weight: 200 (440 lbs.)
Max airspeed: 189 km/h (117 kts) *
Cruise airspeed: 150 km/h (81 kts) *
Min airspeed: 60 km/h (32 kts)
*Presumably with CNA engine.
AM.9 “Tucano” 1947
A two-seat sport aircraft, very
similar to the AM.8. It was the second airplane built by newly founded
ALAPARMA. It had a wing equipped with flaps and the occupants sat on side by
side seats that were staggered to reduce the frontal section. A few photographs
of that time show the twin tail-booms that could be folded up and forward to
facilitate the road transportation of the airplane. This solution was also
adopted later with the AM.10.
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| A picture that shows the foldable twin tail booms of the Tucano |
The engine was the CNA C
II driving a fixed pitch wooden propeller. The prototype, registered I-DONB,
made its first test flight on April 16, 1947, in Parma.
 |
| The Tucano beginning a takeoff run |
The traces of this airplane, that was never certified, were also lost.
Technical data:
Wingspan: 7 m (22.9 ft)
Length: 5.08 m (16.6 ft)
Height: 1.45 m (4.75 ft)
Wing area: 8.5 m² (91.4 sq ft)
Gross weight: 300 kg (661 lbs.)
Max. airspeed: 173 km/h (107 kts)
Min. airspeed: 63 km/h (34 kts)
“Parma” 1947
Single seat glider, designed as an
aircraft easy to build and transport. The rectangular planform, single spar
wing was mounted high on the fuselage. It had a wooden box-like structure
forward of the leading edge, and the aft part of it was covered with fabric.
The structure of the empennage was similar. The fuselage had a wooden structure
covered with wood. The landing skid had rubber disk shock absorbers.
The Parma was designed by Mantelli and built by Emilio Pastorelli at ALAPARMA. It was test-flown on May 29, 1947, towed by the AM.9.
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| The Parma being towed by a bicycle |
Technical data:
Wingspan: 11.30 m (37 ft)
Length: 4.8 m (15.7 ft)
Height: 1.2 m (3.9)
Wing area: 10 m² (107.6 sq ft)
Wing aspect ratio: 12
Glide ratio: 20
Empty weight: 65 kg (143 lbs.)
Gross weight: 155 kg (341.7 lbs.)
Minimum descent rate: .9 m/s (2.9
ft/s)
AM.10 “Trieste” 1947
Among the models designed by Mantelli,
the AM.10 was the one built in the largest, though limited number. It is also
the most widely photographically documented one.
The AM.10 was a two-seat touring
aircraft. The general configuration was analogous to the AM.8 and AM.9 but,
unlike the predecessors, the two occupants were seated side by side.
To simplify the construction, the wing
had no flaps. Two bracing cables, linked to the wing and the horizontal
stabilizer, stiffened the twin tail booms on the horizontal plane.
The initially planned engine was one
CNA C II, modified with a double ignition. That engine, however, never became
available in sufficient numbers (it was a pre-WWII prototype that never reached
production). Therefore, a 45 CV (44.3 hp) Praga B2 engine was selected instead.
 |
| AM.10 with one of the few CNA C II engines ever installed on an aircraft |
Starting in 1949, these AM.10 airframes were completed with heavier and more powerful engines. They were redesignated BALDO 65 (with a 65 CV, 64 hp, Walter Mikron engine) and BALDO 75 (with a 75 CV, 73.9 hp Praga D engine).
Because of these modifications, that
were not approved by the designer, when Mantelli returned from Argentina a
lengthy seven-year legal dispute ensued between him and his partner, which did
not end positively for Mantelli.
 |
| A tryptic of the AM.10 (Baldo 75) that shows the tail booms bracing cables |
The heavier engines and the consequent
change of balance affected the flight characteristics of the AM.10s negatively,
especially with only the pilot on board, creating some handling problems.
Two examples of the AM.10 were built
in Argentina by Mantelli, with the help of the Matzen brothers. These Argentine
aircraft had double vertical stabilizers, as in the AM.6, and an American 65 hp
Continental A65 engine. One of the two aircraft was modified for agricultural
purposes and equipped with special flaps.
|
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|
 |
| The I-CARD in flight, with the Continental A65 engine |
 |
| Adriano Mantelli at the controls of I-CARD |
The present configuration of the I-CARD differs
from the original in having a single central vertical stabilizer, a double
curvature single-piece canopy, the fuses and the stabilizing wheels at the
wingtips. The reasons and the time of these modifications are unknown.
 |
| The modified I-CARD at San Pelagio |
The last AM.10 to fly was the one
registered I-DONN, which was restored by the Marucci brothers, and is now
preserved by the Mantelli family in Trevignano Romano (Rome).
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Technical
data (with 75 CV Walter Praga D engine)
Wingspan: 7 m (22.9
ft)
Length: 5.08 m
(16.6 ft)
Height: 1.45 m
(4.75 ft)
Wing area: 8.5 m²
(91.5 sq ft)
Empty weight: 240
kg (529 lbs.)
Max takeoff weight:
450 kg (992 lbs.)
Max. airspeed: 207
km/h (112 kts)
Cruise airspeed:
177 km/h (95 kts)
Min. airspeed: 72
km/h (38.8 kts)
Range: 730 km (394
NM)
AM.11 “Albatros” 1951
Single seat motorglider. It coupled
the wing of the Parma glider with the fuselage of the twin-boom AM.5.
It was built by Adriano Mantelli in
Argentina at the Albatros Club de Planeadores in Merlo (Greater Buenos Aires)
and so named in honor of the club. It was equipped with a 22 CV, hp 21.6 engine
of unknown type. It underwent a complete set of structural tests and was
test-flown in Merlo with experimental registration LV-X-8.
 |
| The very light AM.11 Albatros |
Technical data:
Wingspan: 10 m (32.8 ft)
Wing area: 10 m² (107.6 sq ft)
Wing aspect ratio: 10
Empty weight: 85 kg (187.3 lbs.)
Max take-off weight: 175 kg (386 lbs.)
Max. airspeed: 150 km/h (81 kts)
Min. airspeed: 45 km/h (24 kts)
Glide ratio: 22
Endurance: 3 hours
AM.12 “Argentina” 1954
Two-seat motorglider with an airframe
analogous to the AM.10’s. The project started during Adriano Mantelli’s stay in
Argentina.
After his reentering the ranks of the
Armed Forces, Mantelli had ceded the design gratuitously to the Italian Air
Force for the purpose of developing an economic training aircraft.
The construction of three examples, in
three different variants, was set up in Guidonia:
A pure sailplane version
 |
| AM.12 sailplane version |
 |
| Jet-powered AM.12 |
 |
| AM.12 with Praga D engine |
The installation of an Ambrosini P-25
engine was also tested.
 |
| AM.12 with P.25 engine |
The first example, with military
registration MM 100035, flew as a glider in 1954 and was subsequently modified
with the other engine installations. The same aircraft set several altitude
world records in the C1a, Group I sub-category:
altitude 6700 m (21,981 ft) with
the Palas turbojet, on December 7, 1962
and in Group II: 8736 m (28,661 ft)
with the Praga D engine.
All these aircraft were later
inexplicably demolished.
Technical data:
Wingspan: 12 m (39.3 ft)
Length: 5.5 m (18 ft)
Height: 1.4 m (4.6 ft)
Wing area: 14.4 m² (155 sq ft)
Wing aspect ratio: 10
Max airspeed (Palas): 220 km/h (118
kts)
Min airspeed: 50 km/h (27 kts)
Empty weight (Palas): 210 kg (463
lbs.)
Max takeoff weight (Palas): 500 kg
(1100 lbs.)
Canguro Various
variants 1960-1962
The soaring activity of Adriano
Mantelli was particularly linked to the C.V.V. 6 Canguro glider, designed by
his friend Ermenegildo Preti.
Mantelli had always enthusiastically
backed the idea of a high performance, two-seat glider, like the Canguro, that
could also be used as a civilian and military trainer.
The presence of Adriano Mantelli with
his inseparable Canguro was a constant in the most important air shows of the
1950s and 1960s.
However, Mantelli did not miss a
chance to apply his inventiveness. One Canguro was converted into a single-seat
sailplane with a mid-fuselage-mounted wing.
 |
| The single-seat Canguro |
 |
| The Ambrosini P.25 engine installation on the Canguro |
Later, a 25 CV (24.6 hp) Hirth Solo engine was
mounted in the same way, but in a tractor position.
However, the most radical modification
of the Canguro was the one applied to the M.M. 100028 (military registration),
on which the wing was mounted at mid fuselage and the Turbomeca Palas turbojet
engine, previously mounted on the AM.12, was installed.
 |
| Jet-powered Canguro Palas |
 |
| Two pictures that show the installation of the wing and the extra fuel tanks on the single seat Canguro, powered by the Palas turbojet engine. |
Unfortunately, very little
remains of the about thirty aircraft generated by Adriano Mantelli’s ingenuity:
The jet power Canguro Palas
M.M. 100028, preserved at Italian Air Force Museum of Vigna di Valle (Rome)
The AM.10 I-DONN, restored
by Enzo and Dino Marrucci, preserved by the Mantelli family.
The AM.10 I-CARD preserved
at the Museo dell’Aria in San Pelagio (Padua).
Nothing is known about the
aircraft built in Argentina.
This was a translation, from Italian, of an
article that appeared on the issue n.142 of Italian magazine Ali
Antiche. It was published here with their permission.
Ali Antiche is the
quarterly publication of the G.A.V.S. Gruppo Amici Velivoli Storici (Friends of
Historic Aircraft Association); an Italian association dedicated to the
preservation of historically relevant aircraft and vehicles.
Your comments and corrections will be
greatly appreciated.
Thank you,
Leonardo Pavese
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