Savoia Marchetti SM.81 in Chinese service

The Savoia-Marchetti SM.81 “Pipistrello” was an Italian bomber introduced in 1935. It was a militarized version of the earlier SM.73 airliner. The plane proved one of the most flexible and reliable aircraft of the Regia Aeronautica between 1935 and 1944. The base SM.83 had 3 engines, and was produced and operated with a wide variety of types.

The model had only one major redesign as the SM.81B, or SM.81bis. This model used two Isotta-Fraschini Asso XI inline engines and sported a streamlined, glazed nose. Otherwise it was unchanged. It was primarily intended as a torpedo bomber. A single prototype was constructed and tested, but it had inferior performance and was not adopted by the Regio Aeronautica.

Chinese Interest

In the 1930, the Chinese Nationalist government in Nanjing under the leadership of Chiang Kai-shek engaged with strategic military co-operation with the Fascist Italian Government under Mussolini. This co-operation resulted in the construction of the Sino-Italian National Aircraft Works (SINAW) in 1936.

One of the aircraft Savoia sold to the Chinese via this joint-venture was this SM.81B. In early December 1936 an order was placed for licence production of six SM.81B’s, with another one to be shipped in from Italy (Ex. MM326). The imported machine arrived in Hong Kong in October of 1937 in nine crates. Likely this was the original prototype). The crates where too large to be shipped by rail, and permission to assemble the aircraft in Hong Kong and ferry it to Nanchang was not granted. The aircraft sat in storage until June 1938, when six crates were shipped to Canton by rail.

Of the six aircraft to be produced by the SINAW, only 3 would be completed before the factory was destroyed by a Japanese air raid on October 20, 1937. Two of those would be delivered, but the third was destroyed by the raid just before acceptance trails. The order for the remaining aircraft was cancelled afterwards due to breakdown in relations between China and Italy.

Operational History

There is a mis-match between the amount of aircraft produced, and pressed into service. The story would imply that only 2 aircraft where service ready; those constructed at SINAW. I could not find evidence that the airframe shipped from Italy was completed at any time. However most sources claim that 3 aircraft where actually used operationally. Whether this is a mistake, or if the shipped SM.81 was actually completed and pressed into service, is unknown. This article will assume 3 operational aircraft.

The bombers where issued to the 第13中隊 (Dì 13 zhōngduì, 13th Squadron) in Nancheng, under command of the Aviation Commission. Autumn 1937, the squadron was re-organized into a bomber squadron. Under squadron leader 李天民 (Lǐ Tiānmín), basic conversion training was started. Nanchang air base at the time however hosted a large amount of troops, making training difficult. 13th Squadron was relocated to Hankou and merged with the 18th and 31st Squadron to form a bomber school under the 8th Group. In addition to the three SM.81B aircraft the school was also assigned one Heinkel He 111A-0 bomber. An American, Barr, was appointed as principal of the new school, with Li Tianmin serving as the deputy principle.

Due to the worsening war situation, the school later located to Yichang. After Barr resigned, he was replaced with another American, John. Due to his unfamiliarity with the terrain, all aircraft were lost in successive accidents in February 1938. The school was closed afterwards.

Specifications

General characteristics

• Crew: 6
• Length: 18.30 m
• Wingspan: 24.00 m
• Height: 4.86 m
• Empty weight: ~6700 kg
• Gross weight: ~10380 kg
• Powerplant: 2 x Isotta-Franschini Asso XI R.C V-12 inline engines, 850 hp each.

Performance

• Maximum speed: 328 km/h
• Cruise speed: 300 km/h
• Range: 2200 km
• Service Ceiling: 8 km
• Time to Altitude:
  • 1000 m in 4 min
  • 2000 m in 7 min 48 sec
  • 4000 m in 15 min 30 sec
  • 6000 m in 24 min 30 sec