The Fw 191 was the Focke-Wulf submission to the German Air Ministry's "Bomber B" program of 1939. Authorities were sold on the concept of high-speed bombers ("schnellbombers") and envisioned fleets of these medium-class, multi-engined aircraft reaching targets all across England from German-held bases across the Channel and able to outrun and trailing adversary. The Fw 191 was certainly a sound design though issues with the required technology (many of its facilities were to be electrically-driven) and engines delayed the project before it was finally doomed altogether along with the Bomber B initiative itself. Only three prototypes were ever completed.
Several major German concerns were in play for the Bomber B requirement and these represented by Arado, Dornier, Junkers and Focke-Wulf. The Arado concept was dropped from contention while slow work was committed to the Dornier submission. Only the Junkers and Focke-Wulf proposals were seriously furthered. The German requirement called for a few specifics such as a pressurized cabin for the flight crew, remote-controlled armament, all-new engine designs (to be provided by either Junkers or Daimler-Benz), a top speed of 600 kmh, excellent endurance over land and water and an internal/external ordnance load of up to 8,800lbs. Focke-Wulf, largely remembered for their excellent Fw 190 single-seat, single-engine fighter of World War 2, proposed their Fw 191 - a twin-engined, multi-crew offering incorporating the many concepts the German Air Ministry sought.
Externally, the Fw 191 fielded a pencil-like, well-streamlined fuselage with its cockpit integrated into the airflow as seen in the German Heinkel He 111 medium bomber (and later in the American Boeing B-29 Superfortress). This allowed for an all-glazed nose section with no cockpit "stepping" to break up the design. Since the crew was amassed in the forward portion of the aircraft, this non-stepped cockpit approach made crew communication excellent and visibility out of the cockpit relatively good. The fuselage tapered at the rear and this was capped by twin outboard vertical tail fins. Wings were fitted at the center of the design and high-mounted for good ground clearance. Engines were fitted into streamlined nacelles along each wing leading edge, the nacelles running past the trailing edges. The undercarriage was wholly retractable to, again, maintain strong airflow about the aircraft. The configuration included two single-wheeled main legs and a single-wheeled tail leg. An internal bomb bay was situated at the center of the airframe while hardpoints inboard of each engine nacelle were considered. As defensive armament was intended to be largely remotely-controlled from within the fuselage, there was a dorsal and ventral turret as well as rear-facing guns at the aft section of each engine nacelle. A tail turret was imagined at the extreme rear of the airframe between the twin vertical fins to counter any pursuing threats. A chin-mounted turreted cannon was also optional and this woudl protect the vulnerable front from head-on attacks by the enemy. Armament would consist of a collection of 7.92mm MG 81 machine guns (2 x chin, 1 x each engine nacelle), 13mm MG 131 machine guns (2 x dorsal turret, 2 x ventral turret) and MG 151/20 cannons (1 x dorsal turret, 1 x ventral turret).
The Fw 191 airframe itself was a strong applicant for the Bomber B program exhibiting speed through its basic appearance. However, the required heavy use of electrics required equally heavy reliance on generators and motors. This not only added weight to the growing design but also made for a more complex engineering end-product. The design was eventually evolved through simplification processes that went on to include conventional manned gun positions (the nacelle guns were dropped altogether) and proven hydraulic and mechanical features began replacing the intended electronically-powered facilities. Despite a more lightened design, the aircraft still suffered from being underpowered - the Junkers Jumo 222 series engines not proving up to the task (the Daimler-Benz offering eventually went abandoned). These program limitations eventually netted just the three Fw 191 prototypes recognized simply as "V1", "V2" and "V6". Additional prototypes intended to solve several key issues were also envisioned though none of these came to pass. By this time in the war, the German situation had changed for the worse and commitments were given to other, more defensive-minded programs. With the end of the Bomber B program, the Fw 191 fell to the pages of military aviation obscurity - joining a plethora of other promising German designs of World War 2.
Performance estimates for the Fw 191 (prototype V6) included a top speed of 620 kmh with a range of 2,240 miles - both within the scope of the Bomber B requirements. The airframe would have featured a service ceiling of approximately 31,800 feet to which a pressurized cabin would have assisted the crew though a later project rewrite eventually dismissed the complicated pressurization equipment altogether. The Fw 191 was to field 9,240lbs of internal and external ordnance including conventional drop bombs and possibly torpedoes - the later for the maritime strike role over water.