Savoia - Marchetti SM . 89 The Savoia - Marchetti SM . 89 was a bomber aircraft made by Savoia - Marchetti . The SM . 89 was developed by Alessandro Marchetti and the prototype ( MM . 543 ) made its first flight in September 1941 in Vergiate , with the test pilot Lieutenant G . Algarotti behind the sticks . Development . The SM . 89 was intended to be a bomber / attack aircraft , something similar to Junkers Ju 88 . The aircraft displayed some impressive features , but it was not a new project , rather an extrapolation from the earlier SM . 84 . The project utilized the wings , the aft fuselage and the mixed construction of the latter almost untouched , with a totally redesigned nose . The fuselage was made from a skeleton of steel tubes , covered with duralumin and wood back as far as the dorsal turret , the remainder of the fuselage being of wood and fabric construction . The wing was made of wood using three spars and a covering of compensate wood . The control surfaces comprised slats and flaps , and the ailerons , that were lowered partially with the flaps to increase lift . The forward fuselage was the real difference between the SM . 84 and SM . 89 . The forward fuselage housed only one pilot , after him there was a radio operator / gunner , and finally a gunner . Therefore the aircraft had only half a crew , compared to the S . 84 . The fuselage was much more cramped than the S . 84 ' s , this was also due to the tandem position for all the crew , because less surface led less protection needed . The aircraft did not have a nose engine , unlike many contemporary Italian designs . The SM . 89 was a two - engine aircraft . In this manner , the nose could be used to house weapons . The nose section was rounded , short and much inclined , to assure the best visibility for attack . The weaponry was mainly based on the 37 mm ( 1 . 46 in ) Breda anti - aircraft guns , used in the anti - tank and anti - ship role . Three 12 . 7 mm ( . 50 in ) Breda machine guns were also fitted in the nose . A further Breda was also fitted in the dorsal turret , and another was in a new model turret , a remote - controlled one , in the ventral position . The aircraft could carry 700 bomblets or 1 , 400 kg ( 3 , 090 lb ) of bombs or torpedo es under the belly . The aircraft could also be fitted with air brakes for dive bombing . The aircraft ' s speed also made it possible to use the aircraft as a bomber interceptor , however it was never fitted with a radar . The Piaggio P . XI engines were however too weak for the aircraft , so instead , they used two Piaggio P . XII RC . 35s , which could develop 1 , 119 kW ( 1 , 500 hp ) at take - off . These engines were in a more compact installation than those of the Piaggio P . 108 s and CANT Z . 1018s . The aircraft could also carry 2 , 700 L ( 710 US gal ) of fuel in self - sealing fuel tank s , which gave the aircraft an effective range of 720 km ( 450 mi ) . This SM . 89 had a very heavy protection . The armour for the front and windscreen totaled 300 kg ( 660 lb ) , another 300 kg ( 660 lb ) of armour protected the engines , and a further 80 kg ( 180 lb ) for the aft armour . The aircraft was also possibly equipped with a CO² fire extinguisher system . Operational service . The aircraft flew in 1941 , but it was not until September 1942 before the aircraft was sent to Guidonia for evaluation tests . The aircraft was taken into use in March 1943 , seeing service in the anti - tank and other roles . The results were quite good , seen the firepower that it had , second only to P . 108A . The real problem about the S . 89 was the power and the reliability of the engines . 2 , 237 kW ( 3 , 000 hp ) was not enough for the 12 , 600 kg ( 27 , 780 lb ) aircraft . It was planned to install Piaggio P . XV or Alfa Romeo 135 engines on the aircraft , but this never took place . The pilots found the aircraft to be difficult to fly , being too slow , and difficult to land . During flight , the aircraft needed to have an elevated angle of attack , so as not to lose altitude . The aircraft was later forgotten and sent to Foligno in July 1943 . It was captured by Germans after 8 September 1943 and vanished . The aircraft could possibly have been more successful had it carried less weapons or armour . Both combined caused the weight to surpass 12 , 000 kg ( 26 , 460 lb ) . The attempt to cover both the attack and even interception requirements made this aircraft even less reliable and flyable than the already mediocre S . 84 .