The Yokosuka D4Y Suisei (彗星, "comet") was a dive bomber of the Imperial Japanese Navy. Its Allied codename was "Judy".

It was developed starting in 1938 at the Yokosuka Naval Air Technical Arsenal, based on two Heinkel He 118 dive bombers that had been supplied by Germany. Service trials demonstrated weakness in the wing structure, a fatal flaw for an airframe subject to the stresses of the dive bombing maneuver, and the initial models were used as reconnaissance planes starting in late 1942.

These problems were fixed by March 1943, and ultimately 2,038 were produced, mostly by Aichi. Lacking armor and self-sealing fuel tanks , the Suiseis did not do well against Allied fighter aircraft. They did, however, cause considerable damage to ships, including the carrier USS Franklin, which was nearly sunk by a single "Judy".

Specifications (D4Y2)

General Characteristics

• Crew: two, pilot, gunner/radio operator
• Length: 10.22 m (33 ft 6 in)
• Wingspan: 11.50 m (37 ft 9 in)
• Height: 3.74 m (12 ft 3 in)
• Wing area: 23.6 m² (254 ft²)
• Empty: 2,440 kg (5,379 lb)
• Loaded: 4,250 kg (9,370 lb)
• Maximum takeoff: kg ( lb)
• Powerplant: 1x Aichi Atsuta AEIA 32, 1,044 kW (1,400 hp)

Performance

• Maximum speed: 550 km/h (342 mph)
• Range: 1,465 km (910 miles)
• Service ceiling: 10,700 m (35,105 ft)
• Rate of climb: m/min ( ft/min)
• Wing loading: 180 kg/m² (37 lb/ft²)
• Power/Mass: 0.25 kW/kg (0.15 hp/lb)

Armament

• 2x forward-firing 7.7 mm machine guns
• 1x rearward-firing 7.92 mm machine gun
• up to 800 kg (1,765 lb) of bombs

Related content

Related development: Heinkel He 118

Comparable aircraft:

Designation sequence: D1A - D2A - D3A - D4Y - D5Y