Ki-21 Type 97 Heavy Bomber "Sally"
Open the military map九七式重爆撃機（Ki-21）
Aircraft
Mitsubishi's Ki-21 was the Imperial Japanese Army's standard heavy bomber from the outbreak of the Second Sino-Japanese War through the first years of the Pacific War. First flown December 18, 1936, it took part in the opening air strikes on British airfields in northern Malaya on December 8, 1941. 2,064 built; increasingly vulnerable to fighter interception by 1943.
- Armament
- 7.7mm九八式旋回機銃×5（機首・背部・腹部・側方・尾部）、12.7mm Ho-103機銃×1（背部旋回銃座）、爆弾1,000kg
History
The Mitsubishi Ki-21, designated Army Type 97 Heavy Bomber (九七式重爆撃機), was the backbone of the Imperial Japanese Army Air Service's strategic bombing capability from the late 1930s through 1944. Allied forces initially codenamed it "Sally" (with the later Ki-21-II called "Gwen").
Development
Designed to a 1936 specification for a bomber capable of 400 km/h and 750 kg of bombs, the Ki-21 prototype first flew on December 18, 1936. Two competing prototypes (Ki-21 by Mitsubishi and Ki-19 by Nakajima) were evaluated, with Mitsubishi winning the contract. It was ordered into production in November 1937 as the Type 97 Heavy Bomber, and entered service in August 1938.
Total production reached 2,064 aircraft — 1,713 by Mitsubishi and 351 by Nakajima under license.
Opening Blows
The Ki-21 wrote its name into history on December 8, 1941 (local time), when aircraft of the 3rd, 12th, 60th, and 98th Air Groups departed bases in French Indochina to bomb the airfields at Alor Star, Sungai Petani, and Butterworth in northern Malaya — among the first Japanese air attacks of the Pacific War, flown on the same day as the Pearl Harbor attack (the first raid on Singapore, before dawn that day, was made by Navy G3M bombers).
During the Malayan campaign, Ki-21s destroyed British airpower on the peninsula within days. Over Burma, they supported the swift conquest that cut the Burma Road to China.
Decline
By 1943, the Ki-21 was obsolete by Allied fighter standards. Its modest defensive armament (multiple 7.7mm guns) and lack of self-sealing fuel tanks made it increasingly costly to operate. Units in New Guinea and the Philippines suffered heavy losses. The Ki-21 was gradually replaced by the Ki-49 Donryu and Ki-67 Hiryu, though it continued transport and training roles until 1945.
Some Ki-21s were converted for the Giretsu Kuteitai (義烈空挺隊) special operations unit — airborne commandos who crash-landed modified Ki-21s on Okinawa's Yomitan Airfield in May 1945 to destroy American aircraft on the ground (the unit had originally been formed to attack the B-29 bases in the Marianas).
Specifications (Ki-21-IIb)
- Engines: 2× Mitsubishi Ha-101 radial, 1,500 hp each
- Max speed: 485 km/h at 4,720m
- Range: 2,700 km
- Empty weight: 6,070 kg
- Bomb load: 1,000 kg internal
Related sites (4)
- Battle6.190, 100.400
Alor Star, northern Malaya — Ki-21s bombed the airfields at Alor Star, Sungai Petani and Butterworth on December 8, 1941
- Battle29.560, 106.550
China theater (Chongqing) — Ki-21s flew long-range bombing missions over China from autumn 1938, including the strategic bombing of Chongqing
- Deployed10.823, 106.630
Saigon area, southern French Indochina — Ki-21 units based in Indochina launched the December 8, 1941 attacks on airfields in northern Malaya
- Factory35.117, 136.900
Mitsubishi Nagoya Aircraft Works, Nagoya — primary Ki-21 production
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