Savoia-Marchetti SM.93

SM.93
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SM.93 with Luftwaffe insigna
Type	Dive bomber
Manufacturer	Savoia-Marchetti
Maiden flight	31 January 1944
Number built	1 prototype only

The Savoia-Marchetti SM.93 was an Italian dive-bomber aircraft designed by Alessandro Marchetti. It flew for the first time on 31 January 1944, near Varese.

Design

The aircraft was a monoplane, with a retracting undercarriage and monocoque fuselage. The wing was three piece, (external and internal wings, in contact with its fuselage), with two-spar as a compromise between ruggedness and weight.

The aircraft was all wood in structure and skinning. Plywood and wood, but also fabric was used for all of the aircraft, and not even the fuselage skeleton was made of steel, as was the 'norm' for Savoia-Marchetti aircraft.

The second unusual feature was the prone position that the pilot occupied. It was meant to better resist the accelerations typical of a dive bomber, especially because the aircraft was capable of very high speeds. The rear gunner sat in a conventional upright position. Despite the prone seat for pilot, the cockpit had a high structure, because the engine was practically below the pilot's seat. A curious feature was the roof of cockpit, made in wood instead of glass, resembling the older bombers SM.79 and SM.84.

The engine was a Daimler-Benz DB 605, a powerful engine capable to assure high performances. Apparently it was also served by a reasonable amount of fuel, to assure an high endurance.

Armament consisted of a 20 mm cannon, with 150 rounds, firing through the propeller hub, two 12.7-mm Breda machine guns placed in the wings, with 350 rounds each, and finally another Breda on a flexible mounting in the rear cockpit, manned by the gunner. A maximum bombload of 820 kg could be carried on the fuselage centreline. Maybe this was meant as the carriage of a new type of bomb, already fitted for SM.91s, that could carry a maximum of 1,640 kg (3,600 lb).

Development

The prototype aircraft had made 16 test flights, a total of 6 hours 40 minutes, by 29 March 1944. During these tests speeds of up to 900 km/h were achieved thanks to the power of the engine and the clean aerodynamics, but at that point the German Control Commission, effectively running RSI weapons production, ordered the end of flight testing.

Although the aircraft had several interesting features, in particular the prone seat for the pilot and an overall very good performance, it also had some shortcomings. The prone position was ideal for dive-bombing, but was extremely uncomfortable in standard flight, and none of the many aircraft that experimented with it were put into production. The wooden structure was not exactly ideal for a dive-bomber either, and this aircraft was the only one of this category to be made of such material. The performance was very good, but not so impressive with a full bomb load. In any case, this aircraft was built too late for the war, and the few test flights were performed with German engines.

Specifications (SM.93)

General characteristics

• Crew: two, pilot & rear gunner
• Length: 10.93 m (35 ft 10 in)
• Wingspan: 13.90 m (45 ft 7 in)
• Height: 3.80 m (12 ft 6 in)
• Wing area: 31.10 m² (334.6 ft²)
• Empty weight: 3,552 kg (7,814 lb)
• Loaded weight: 5,500 kg (12,100 lb)
• Powerplant: 1× Daimler-Benz DB 605A radial engines, 1100 kW (1475 hp)

Performance

• Maximum speed: 515 km/h at 4500 m, 542 km/h at 7000 m (with bombload), 580 km/h at 7000 m (clean) (313 knots, 360 mph)
• Cruise speed: 505 km/h (272 knots, 313 mph) at 7000 m
• Range: 1,650 km (891 nm, 1025 mi)
• Service ceiling: 8,200 m (26,900 ft)

Armament

• 1 × 20 mm MG 151/20 cannon (150 rounds) firing through the propeller hub
• 2 × 12.7 mm Breda-SAFAT machine guns (700 rpg) in the wings
• 1 × 12.7 mm Breda-SAFAT machine gun on a flexible mounting in the rear cockpit
• Bombs up to 820 kg (1,800 lb)

External links

• Savoia-Marchetti SM.93

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Savoia-Marchetti SM.93".