Savoia-Marchetti SM.91

{{Infobox aircraft

| name = SM.91

| image = Sm91.jpg

| image_border = yes

| caption =

| type = {{Plainlist|

| national_origin = Italy

| manufacturer = Savoia-Marchetti

| designer =

| first_flight = 11 March 1943

| introduction =

| retired =

| status = Retired

| primary_user = Regia Aeronautica

| more_users =

| produced =

| number_built = 2

| unit cost =

| developed_from =

| variants =

| developed_into =

}}

The Savoia-Marchetti SM.91 was a two-seat, twin-engined, Italian heavy fighter prototype, designed to compete in a 1942 revision to a long-range fighter-bomber contract offered by the Regia Aeronautica to Italian aircraft companies in 1938. The original 1938 specification yielded the Savoia-Marchetti SM.88, which the SM.91 was largely based on.

Design and development

In July 1942, the Regia Aeronautica requested designs for a new aircraft, propelled by the German DB 605 engine, capable of flying at 620 km/h (385 mph) with a range of {{convert|1,600|km|mi|abbr=on}}. The armament should consist of six MG 151 cannons in the nose and wings and a 12.7 mm Breda-SAFAT machine gun as a defensive weapon. It should have an {{convert|800|kg|lb|abbr=on}} bomb load. At that point, the request for a long-range fighter killed the SM.88, still in development, and the SM.91, a larger, heavier and more modern design, was authorized.

The fuselage and the wings were all-metal, to achieve the best performance regardless of cost. The central nacelle held the crew of two, and the wings and tail were similar to the SM.88. Fuel capacity was 1,600 L, but with auxiliary tanks could be raised to 1,800 L. It is unknown if it was capable of a range of {{convert|1,600|km|mi|abbr=on}}.

The two DB 605 engines gave a total of 2,950 hp. The aircraft's maximum speed at 585 km/h (363 mph) was better than the SM.88. There were three 20 mm MG 151s in the nose. Two more were mounted in the wings, close to the fuselage. Another machine gun was provided for the rear gunner. Total bomb load was {{convert|1,640|kg|lb|abbr=on}} or a torpedo.

The prototype, designated MM.530, flew for the first time on 11 March 1943, tested by Aldo Moggi. There were two prototypes, the second a modified SM.88 prototype.

The machine flew at Vergiate and logged 27 hours in the next few months. It was advanced, but was not entered into the official tests at Guidonia, perhaps because it was still undergoing testing. The first prototype was captured and sent to Germany in October 1943, after which it vanished and is presumed destroyed. The second prototype, in an incomplete state, was captured by the Germans when they occupied northern Italy in September 1943. This aircraft was tested on 10 July 1944, but was destroyed by Allied bombers later in the year.

Specifications (SM.91)

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{{Aircraft specs

|ref=Italian Civil and Military Aircraft 1930–1945 {{cite book |last=Thompson |first=Jonathon W. |title=Italian Civil and Military Aircraft 1930–1945 |url=https://archive.org/details/italiancivilmili00libg |url-access=limited |year=1963 |publisher=Aero Publishers Inc. |location=USA |isbn=0-8168-6500-0 |page=[https://archive.org/details/italiancivilmili00libg/page/n143 285]}}

|prime units?=met

|crew=2 (pilot and rear gunner)

|length m=13.25

|length note=

|span m=19.7

|span note=

|height m=3.85

|height note=

|wing area sqm=41.76

|wing area note=

|aspect ratio=

|airfoil=

|empty weight kg=6400

|empty weight note=

|gross weight lb=19600

|gross weight note=

|max takeoff weight kg=

|max takeoff weight note=

|fuel capacity={{cvt|1600|L|USgal impgal}} + optional {{cvt|825|L|USgal impgal}} drop-tank{{citation needed|date=December 2019}}

|more general=

|eng1 number=2

|eng1 name=Daimler-Benz DB 605A-1

|eng1 type=V-12 inverted liquid-cooled piston engines

|eng1 note={{cvt|1475|PS|hp kW|0}}

|prop blade number=3

|prop name=constant-speed propellers

|prop dia m=

|prop dia note=

|max speed kmh=584

|max speed note=at {{cvt|7000|m}}

|max speed mach=

|cruise speed kmh=515

|cruise speed note=

|stall speed kmh=

|stall speed note=

|never exceed speed kmh=

|never exceed speed note=

|minimum control speed kmh=

|minimum control speed note=

|range km=1600

|range note=

|combat range km=

|combat range note=

|ferry range km= 1000

|ferry range note=

|endurance=

|ceiling m=11000

|ceiling note=

|g limits=

|roll rate=

|climb rate ms=

|climb rate note=

|time to altitude={{cvt|6000|m}} in 8 minutes 30 seconds

|wing loading kg/m2=

|wing loading note=

|disk loading kg/m2=

|disk loading note=

|fuel consumption kg/km=

|power/mass=

|thrust/weight=

|more performance=

|guns= 6 × {{cvt|20|mm|3}} MG 151 cannon (three in the nacelle nose, two in the wing-roots and one in the rear cockpit.)

|bombs= {{cvt|1640|kg|0}} bombload:- 4x {{cvt|100|kg|0}} bombs or 4x {{cvt|160|kg|0}} bombs or 1x {{cvt|500|kg|0}} bomb or 1x torpedo or 1x {{cvt|825|L|USgal impgal}} drop-tank

|avionics=

}}