Fiat AS.1

Fiat

Industry	Aerospace
Founded	1899 in Italy
Headquarters	Italy
Products	Automobiles, aircraft

The Fiat AS.1 was a lightweight touring monoplane crafted and manufactured by the Italian firm Fiat.

Featuring a straightforward and traditional layout, the AS.1 incorporated a parasol wing configuration, a tailskid-type landing gear, and tandem open cockpits accommodating the pilot and one passenger or trainee. Its construction utilized an all-wood framework enveloped by plywood and fabric, with metal sheathing applied around the nose section. A subsequent variant known as the TR.1 introduced a metal airframe combined with a wing of reduced span.

This model gained significant popularity, culminating in a production volume surpassing 500 units. About half of these were acquired by the Regia Aeronautica for use primarily as trainers and liaison aircraft.

Design

The Fiat AS.1 was engineered as a light monoplane featuring two seats, designed for extended touring flights and pilot instruction. Both occupants were housed within an enclosed cabin, with the passenger customarily seated ahead of the pilot. The aircraft generally included dual sets of flight controls, though the forward controls could be disengaged at the pilot’s discretion. Positioned immediately behind the pilot was a spacious baggage compartment; its variable load could be balanced through adjustments to the stabilizer.

Structurally, the fuselage, wings, and tail surfaces were supported by a tubular framework comprised entirely of duralumin, except for various steel fittings. The forward fuselage section was partially clad in metal panels, while fire-resistant fabric covered the remaining rear portion behind the cockpit.

Visibility from within was enhanced by large windows on both sides and at the front of the cabin. Specially designed windshields allowed both pilot and passenger to extend their heads outside without full exposure to strong airflow. The pilot’s station also featured a transparent cabin roof to improve upward visibility. Active ventilation systems maintained comfortable cabin conditions.

The fuselage’s transverse frames and sidewalls were constructed to allow generous unobstructed interior space and accommodate relatively large doors without increasing external dimensions excessively. Four doors were installed—two on each side—to enhance occupant safety. Additionally, a mechanism was incorporated to facilitate door opening during flight emergencies, easing rapid egress.

Power was typically supplied by a single Fiat A.50 seven-cylinder air-cooled radial engine delivering up to 100 horsepower at 1,900 rpm; however, some units were equipped with alternative powerplants such as the more potent Fiat A.53 radial engine. Fuel was stored in steel tanks mounted atop the cabin roof with a capacity of 125 liters (33 gallons). Optional supplementary tanks holding approximately 45 liters (12 gallons) each could be installed within the cabin space. An oil tank featuring a finned radiator was located beneath the forward rudder bar, holding 10 liters (2.6 gallons). Fuel delivery relied on an engine-driven pump capable of maintaining consistent flow even during extended aerobatic maneuvers.

The engine mount consisted of a thick duralumin plate bolted to steel fittings supporting structural struts designed to absorb engine vibrations effectively. The cowling followed the fuselage contour to present a sleek profile without compromising cooling efficiency.

The wing framework comprised two triangular spars supported by struts connecting to the fuselage base. Ribs were fabricated from square-section duralumin tubing reinforced with triangular bracing; similar tubing was used for spars that were lightened internally yet strengthened where necessary to support wing covering loads. The spar walls formed girders braced laterally by diaphragms tailored to withstand expected shear stresses. Steel fittings joining spars were typically riveted and soldered for durability.

Each half-wing’s spars attached to the central fuselage via simple hinges rather than being rigidly fixed, with box ribs joining corresponding fuselage ribs to create an optimal wing-fuselage junction. Measures were taken to stiffen wing structures against stress transmitted through coverings. Struts linking wing spars to the fuselage were made from faired duralumin tubes reinforced appropriately for secondary load handling.

The undercarriage featured a wide track providing excellent lateral ground stability. The forward landing gear struts incorporated long-stroke oleopneumatic shock absorbers that reduced strut length while giving them a slender and refined appearance. As typical for monoplanes of this period, undercarriage stresses were primarily axial.

Axles constructed from high-tensile steel were shaped to maximize stiffness while minimizing weight and hinged at symmetry planes on struts attached to the fuselage, limiting lateral wheel movement effectively. Each axle included devices reducing braking loads on the assembly; brakes could be operated manually or via rudder bars to assist ground maneuvering.

The tail skid employed three steel rods arranged in a pyramid shape with its apex contacting the ground; two rods hinged coaxially perpendicular to the fuselage’s vertical symmetry plane, while a third vertical rod equipped with rubber disk shock absorbers connected internally within the fuselage and hinged at its lower end to a spoon-shaped skid equipped with a guiding rib. This unconventional design aimed to reduce ground digging tendencies.

Large tail surfaces shared similar duralumin structural characteristics as those of the wings. An adjustable stabilizer was fitted but could only be altered on the ground; however, it provided effective control adaptation during flight operations. Rudder control utilized dual cables, whereas elevator movement was managed through a rigid linkage operated by a single lever.

The stabilizer featured a rectangular notch in its leading edge for adjustment mechanisms; elevators included balancing projections near their leading edge tips. The hinge axle at the leading edge was encased in duralumin sheeting matching a corresponding cover on the stabilizer’s rear spar, both shaped aerodynamically to reduce drag.

Structurally, stabilizers resembled those used for ailerons in design and construction quality.

Operational history

The AS.1 aircraft demonstrated notable success in various competitions and record-setting attempts. In August 1929, these models took part in the international Challenge 1929 event. Subsequently, in January 1930, an AS.1 flown by Renato Donati accompanied by mechanic Gino Capannini established new records for endurance, distance, and altitude within its category, achieving durations of 29 hours 4 minutes 14 seconds, covering 2,746.2 km (1,706.4 mi), and reaching an altitude of 6,782 m (22,251 ft), respectively. On December 28, 1932, Furio Niclot and Mariano Lanciani piloted a version powered by a 127 kW (170 hp) CNA C-7 nine-cylinder radial engine to set a seaplane altitude record for its class at 7,362 m (24,154 ft). Two days later, by replacing the wheels with floats, the identical aircraft established the landplane altitude record at 9,282 m (30,453 ft). Among long-range accomplishments were flights from Rome to Mogadishu and from Vercelli to Tokyo, both completed by Francis Lombardi with Gino Capannini. Additionally, an aerial circumnavigation of Africa was completed by Francis Lombardi, Count Lodovico Mazzotti, and Mario Rasini, covering a distance of 27,600 km (17,150 mi) over 54 days.

In 1931, the TR.1 variant also achieved competitive victories in the Giro Aereo del Piedmonte and Giro Aereo d'Italia races.

Variants

• AS.1 – original model equipped with a Fiat A.50 engine.
  • AS.1 Idro – floatplane adaptation.
  • AS.1 Sci – fitted with skis for snow operations.
• AS.2 – reinforced airframe combined with the Fiat A.50 S engine.
• TR.1 – featured a metal airframe construction, reduced wingspan (9.00 m; 29 ft 6.5 in), and an enclosed cockpit.

Operators

Template:BRA

• Brazilian Air Force – operated one unit.

Template:Country data Ethiopia

• Ethiopian Air Force

Template:ESP

• Spanish Air Force

Specifications (AS.1)

File:Fiat TR-1 3-view NACA Aircraft Circular No.130.jpg

Three-view drawing of the Fiat TR-1 from NACA Aircraft Circular No.130

Sources

• "The Fiat 'T.R.1' Training and Touring Airplane (Italian): A Two-Seat High-Wing Monoplane" National Advisory Committee for Aeronautics, 1 December 1930. NACA-AC-130, 93R19548.

External links

• Fiat featured in Flight, 4 April 1930