In January 1944, Heinkel was persuaded by Oberstleutnant Knemeyer to begin work on a four-engined jet bomber, that could be ready in the quickest possible time frame. Although Heinkel had been working on a similar project (P.1068), it was decided to take a proven design (Arado Ar 234) and enlarge the dimensions. The He 343 (this designation was  submitted to the RLM on March 14, 1944) was to have a 1.55:1 larger wing than the Ar 234, and the linear dimensions were to be increased by 1.25:1. The He 343 was also know unofficially as the Strabo 16 (Strabo was an abbreviation for Strahlbomber (Jet Bomber), and the takeoff weight was to be 16 tons), before the 343 number was issued.
          The enlarged fuselage had space for an internal bomb bay and for the newly designed main gear, which were double-braked. The wings were mounted mid-fuselage and were unswept. Four jet engines were to be mounted singly beneath the wings. The flexibility of the He 343 design really came into play here, as virtually any turbojet could be used. At first, the Jumo 004B was to be used, but it was hoped that the Jumo 004C would be ready by the time the He 343 prototype was finished. Also, the BMW 003 or the He S 011 jet engines could be fitted. On the planned production aircraft, the engines needed to be moved forwards a bit to clear the planned single,  trailing edge flap. The nose and cockpit was newly designed, and a crew of two was to sit in the pressurized cockpit. The nose gear was also completely new, and was offset 100 mm (4 inches) to the port side from the centerline of the aircraft.
          There were four main versions of the He 343 planned, these were:

• He 343A-1, which was to be the bomber version. Depending on the engines used, the bomb load ranged between 2000 kg to 3000 kg, with 2000 kg to be carried internally, and 1000 kg to be carried externally. Trials were to be held with the Fritz X radio controlled bomb, which would have also added a third view member. Defensive armament consisted of two fixed rear firing MG 151 20 mm cannon with 200 rounds each, which were mounted in the rear fuselage.

• He 343A-2, the reconnaissance version, was to be similar to the A-1, except instead of a bomb load, two Rb 75/30 cameras were to be carried in the bomb bay, along with an additional fuel tank that held 2400 kg of fuel to extend the range. Two fixed rear firing MG 151 20 mm cannon with 200 rounds each, as in the A-1, were mounted in the rear fuselage for defensive fire purposes.

• He 343A-3 was the first Zerstörer (Destroyer) version. The standard armament was to be four forward firing MK 103 30mm cannon with 400 rounds each, which were mounted in the bomb bay, or two forward firing MK 103 30mm cannon with 100 rounds each and two forward firing MG 151 20mm cannon with 200 rounds each. Weapons with calibers of up to 50 mm could be used, although all the forward firing guns had to be placed to fire from the starboard side under the fuselage nose, due to the nose wheel which retracted to the rear and was on the port side. Again, like the A-1 and A-2 variants, defensive armament consisted of two fixed rear firing MG 151 20 mm cannon with 200 rounds each, which were mounted in the rear fuselage.

• He 343B-1, which was also to be a Zerstörer (Destroyer), the main difference was that instead of the two fixed rear firing guns in the fuselage rear, a FHL 151Z remote controlled turret was installed in the extreme rear fuselage. This necessitated a tail redesign to a twin fin and rudder set up. A rear facing periscope in the cockpit was used to aim the FHL 151Z turret, which was armed with two MG 151 20mm cannon. The twin tail would have made for extended flight testing, plus would have added additional weight and drag.

*Some sources state that a prototype He 343 was completed, but was either destroyed in a bombing raid or was scrapped before the first test flight.

     View Heinkel He 343 model photos                   View Josha Hildwine's He 343 Luft Art images
 

                Heinkel He 343A-2 Reconnaissance

                  Heinkel He 343B-1 Zerstörer

Weapon arrangement of 4 MK 103 in the  fuselage for use as a Zerstörer (Destroyer)