SM.91

SM.91

▄Ju 87 D-3

SM.92

SM.91

▄Ju 87 D-3

SM.92

Italy

II Rank

Battle rating:

AB	RB	SB
3.7	3.7	4.0

Class:

Strike aircraft

Research:11 000

Purchase:22 000

Description

During 1942, the Regia Aeronautica required a defence fighter to provide a defence against bombers accelerating the advance of Allied troops into Italy. The SM.91 was created, a twin-engine fighter with DB 601 engines, armed with six 20 mm MG 151s up front and a turret equipped with a 20 mm MG 151 controlled by the gunner. 2 were created, taking flight for the first time on 11 May 1943, and achieved 27 hours of flight time but never entered official evaluations. One was captured by the Germans, while the other was destroyed by Allied bombing raids.

Introduced in Update 1.85 "Supersonic", the SM.91 looks like a normal heavy fighter with a very good frontal armament capable of destroying an enemy aircraft or a light or medium tank very easily with a single burst, however the performance of the aircraft allows it to recover quickly enough when it loses a lot of speed, unlike other heavy fighters. In addition to this, it equips a small rear turret with a 20 mm cannon with which you can easily defend yourself from enemy fighters.

General info

Flight performance

Air brakes

Allows you to dramatically reduce the flight speed by releasing special flaps

Max speed

at 7 010 m585 km/h

Turn time20 s

Max altitude9 500 m

Engine2 х Daimler-Benz DB-605A1

TypeInline

Cooling systemWater

Take-off weight9 t

The SM.91 fulfils a similar role to the P-38 when flown as an interceptor: a twin-engined fighter that is surprisingly capable as a dogfighter due to its good turn rate, especially when spaded. The twin Piaggio P.XI RC.40 12 cylinder inline engines, which happen to be a pair of the powerful DB 605 Inverted V12 engines, are placed away from the cockpit, meaning its hard to take them out in a head-on. However, the heavy nature of the plane means that its acceleration is quite sluggish at low altitudes. The aircraft also sports leading edge wing slats that shorten the turning circle and has airbrakes that can help it slow down in a dive and help when landing on an airfield, which is already fairly easy due to its tri landing gear.

Characteristics	Max Speed (km/h at 7,010 m)		Max altitude (metres)	Turn time (seconds)		Rate of climb (metres/second)		Take-off run (metres)
	AB	RB		AB	RB	AB	RB
Stock	561	546	9500	21.1	21.9	9.3	9.3	300
Upgraded	610	585		19.0	20.0	15.3	12.0

Details

Features
Combat flaps	Take-off flaps	Landing flaps	Air brakes	Arrestor gear
✓	✓	✓	✓	X

Limits
Wings (km/h)	Gear (km/h)	Flaps (km/h)			Max Static G
		Combat	Take-off	Landing	+	-
845	300	535	450	260	~10	~5

Optimal velocities (km/h)
Ailerons	Rudder	Elevators	Radiator
< 280	< 200	< 450	> 380

Compressor (RB/SB)
Setting 1
Optimal altitude	100% Engine power	WEP Engine power
5,800 m	1,232 hp	1,387 hp

Survivability and armour

Crew2 people

Speed of destruction

Structural845 km/h

Gear300 km/h

• No armour
• Self-sealing fuel tanks (1 in each centre wing, 1 in each frontal section of tail, 3 in each wing)

The SM.91 has a good survivability, being able to take multiple 12.7 mm hits before going down; however, be careful when the enemy has 20 mm cannons or higher since they will cause serious damage to your aircraft fuselage and engines.

One DB 605 Inverted V12 engine is powerful enough to keep the aircraft flying in case of losing the other one, however; use of Manual Engine Controls is vital in this situation. Detailed explanation below.

Modifications and economy

Repair costBasic → Reference

AB575 → 731

RB908 → 1 155

SB2 024 → 2 576

Total cost of modifications10 320

13 700

Talisman cost750

Crew training6 300

Experts22 000

Aces250

Research Aces220 000

Reward for battleAB / RB / SB

40 / 80 / 160 %

124 / 124 / 124 %

Modifications

Flight performance	Survivability	Weaponry
Fuselage repair Research: 520 Cost: 690 85 Radiator Research: 520 Cost: 690 85 Compressor Research: 780 Cost: 1 000 125 Wings repair Research: 650 Cost: 860 105 Engine Research: 650 Cost: 860 105 Engine injection Research: 1 100 Cost: 1 500 180	Airframe Research: 780 Cost: 1 000 125 Cover Research: 1 100 Cost: 1 500 180	mg15120_turret_belt_pack Research: 520 Cost: 690 85 GP50 Research: 520 Cost: 690 85 mg15120_turret_new_gun Research: 780 Cost: 1 000 125 mg15120_belt_pack Research: 650 Cost: 860 105 GP100 Research: 650 Cost: 860 105 mg15120_new_gun Research: 1 100 Cost: 1 500 180

Armaments

Offensive armament

Weapon 16 x 20 mm MG 151 cannon

Ammunition1 800 rounds

Fire rate700 shots/min

The SM.91 is armed with:

• 3 x 20 mm MG 151/20 cannons, nose-mounted (300 rpg = 900 total)
• 1 x 20 mm MG 151/20 cannons, chin-mounted (300 rpg)
• 2 x 20 mm MG 151/20 cannons, wing-mounted (300 rpg = 600 total)

The SM.91 has 6 of the powerful MG 151/20s mounted in the centre of the aircraft and can utilise the minengeschoss round. Use "Stealth" or "Air targets" belts for best effectiveness.

Suspended armament

List of setups (2)

Setup 16 x 50 kg GP 50 bomb

Setup 26 x 100 kg GP 100T bomb

The SM.91 can be outfitted with the following ordnance:

• Without load
• 6 x 50 kg GP 50 bombs (300 kg total)
• 6 x 100 kg GP 100 bombs (600 kg total)

The SM.91 can carry up to 6 x 100 kg bombs, which makes it useable in ground forces battles. Due to the rather small size of the bombs, you have to be extra accurate when dropping bombs.

Defensive armament

Turret20 mm MG 151 cannon

Ammunition350 rounds

Fire rate750 shots/min

The SM.91 is defended by:

• 1 x 20 mm MG 151/20 cannon, dorsal turret (350 rpg)

The SM.91 can defend itself very well from any tailing aircraft. Use "Universal" belts for the most effective defensive fire.

Usage in battles

When flying it as an interceptor, it can shred bombers apart with its powerful armament and can ward off escorts who try to tail it with its single 20 mm cannon. However, it is paramount that you come in from oblique angles when attacking bombers, as their gunners can easily take out your pilot due to your lack of armour and bulletproof glass.

When flying it as a ground attacker, be wary that carrying the max payload will significantly decrease performance and you will be a prime target for low flying fighters like Yaks and Spitfires. However the maximum payload is rather weak, only 6 x 100 kg bombs with a max armour penetration value of 91 mm and a blast radius of 4 m. This means that you must land a near perfect or direct hit on medium and heavy tanks in order to destroy them.

On Simulation Mode

While flying on simulation mode you can take your time to reach a safe altitude around 3,500 to 5,000 m climbing within ally air space. Keep in mind that you should use this aircraft with a Boom and Run mindset, that being the case, you should dive on your target while remaining hidden for your enemy as long as possible. Remember that in order to concentrate your burst mass in one zone, and hence having a greater chance to destroy the enemy plane (module; i.e., wings, tail) in one pass, you should open fire according to the gun targeting distance you are using, being a good setup from 300 m to 500 m.

With your 6 x 20 mm MG 151/20 cannons you will be able to shoot down almost every enemy aircraft on your gunsight. However, always check the surroundings before attacking, you dont want to get swarmed after engaging with an enemy. You have to remember that most enemy aircraft, save bombers, are faster and turn better than you. Therefore, you need to choose your targets wisely.

If everything mentioned before goes wrong and you end up with an enemy, or in the worst case, multiple of them going after you, you still have one chance to get out of that situation alive and it is your dorsal turret. The plane is equipped with a 20 mm MG 151/20 cannon and, when used correctly, it can pose a serious threat to most enemy fighters tailing you.

It is recommended to perform evasive manoeuvres and wait until the enemy behind you gets in a range of <500 m, practically point blank. Therefore you will have an easier time leading your bullets in the enemy direction; when successfully hitting an enemy at this range it will just take a couple of direct hits to set the bandit on fire, or if you get a good shot at his wings, send him down immediately.

Counter-tactics

Do not head-on this plane, the 6 x 20 mm cannons will most likely destroy your plane and do not underestimate the defensive cannon. Armed with minengeschoß belts, the nose-mounted cannons can easily cut your wings or set you on fire.

It is best to attack this plane from below since the deffensive 20 mm MG 151/20 cannon won't be able to aim lower than just a few degrees below the tail. Keep also in mind that even a P-47 can outturn it, so if an SM.91 gets behind you, force him to turn and make it lose energy.

If you are flying an aircraft with decent performance in vertical manoeuvres, force the SM.91 to fight on the vertical. Due to the deficient acceleration capacity combined with a bad performance when going vertical, you will most likely get guns on target rather easily with this tactic.

Manual Engine Control

MEC elements
Mixer	Pitch	Radiator			Supercharger	Turbocharger
		Oil	Water	Type
Not controllable	Controllable Not auto controlled	Controllable Not auto controlled	Controllable Not auto controlled	Separate	Not controllable 1 gear	Not controllable

The SM.91 has a very forgiving MEC, therefore don't worry about killing your engine and try different settings according to the maps conditions.

As a general setting you can: set the water and oil radiator at 30%, it will be a long time before cooling off is needed if using 100% throttle, however if WEP is engaged then you will need to open both radiators up to 45%; propeller pitch set at 100% when climbing and lower it to 85%-90% when going horizontal.

If the engines take damage, it will usually be only one of them. That said, the SM.91 is able to fly with only one of its engines working. However, try to extend its life span or even keep the engine alive until you are back at the airfield to repair.

In order to do this, set the damaged engine (or both, if that's the case) as follows: water and oil radiator at a 100%, propeller pitch at 0% to 30% depending if you really need a boost to, for example, get over a hill; and throttle to 50%.

Pros and cons

Pros:

• Devastating armament: 6 x centre-mounted 20 mm MG 151 cannons will make quick work of any aircraft
• Great for head-ons
• Main armament has a large ammo capacity
• Gets an attacker spawn (AB/RB)
• 20 mm MG 151 cannon in the back turret
• Surprisingly good turn rate
• Can act as a powerful interceptor
• Made entirely out of metal, so it can take some punishment.
• Fuel tanks are self-sealing

Cons:

• Tail is prone to snapping when under fire
• No armour protection
• Big target
• Lack of bulletproof glass means pilot is susceptible to getting knocked out, especially in head-ons
• Wings are littered with fuel tanks
• Carrying the largest payload has a noticeable effect on performance
• High tendency to flip forwards upon landing when braking

History

In 1942, the Regia Aeronautica requested a new, long range aircraft that was to be powered by the German DB 601 Inline Inverted V12, carry an 800 kg bomb load, have 6 x 20 mm main armament and a single 20 mm rear cannon. Savoia-Marchetti had previously worked on the SM.88 heavy fighter and the request for a long range fighter disqualified the 88, as it only had a 1,250 L fuel capacity. SM started to work on a new fighter named the SM.91 that was made entirely out of metal, had 6 x 20 mm MG 151 cannons (7 if you count the rear gunner) provided by Germany, was powered by two DB 605 engines and had a range of 1,600 km with a 1,600 L fuel capacity that could be enlarged to 1,800 L with auxiliary tanks.

The two prototypes that were produced made their maiden flight on the 11th of May, 1943 and logged 27 hours at Vergiate. However, it was never entered into the official trials, mainly due to it still being in testing. The first prototype was captured and sent to Germany, and the second prototype was presumed to have been destroyed by bombers.

Media

Skins

• Skins and camouflages for the SM.91 from live.warthunder.com.

Videos

Best twin-boom aircraft discusses the SM.91 at 03:11 - War Thunder Official Channel

See also

• SM.92

External links

• Official data sheet - more details about the performance