Focke-Wulf Fw 191
Encyclopedia
The Focke-Wulf
Fw 191 was a prototype
German
bomber
of World War II
. Two versions were intended to be produced, a twin-engine version using the Junkers Jumo 222 engine and a four-engine variant which was to have used the smaller Daimler-Benz DB 605
engine. The project was eventually abandoned due to technical difficulties with the engines.
, the RLM issued a specification for a high-performance medium bomber
(the "Bomber B
" program). It was to have a maximum speed of 600 km/h (370 mph) and be able to carry a bomb load of 4,000 kg (8,820 lb) to any part of Britain from bases in France or Norway. Furthermore, the new bomber was to have a pressurized
crew compartment, of the then-generalized "stepless cockpit" design (with no separate windscreen for the pilot) pioneered by the He 111P
shortly before the war and used on most German bombers during the war, remotely-controlled armament, and was to utilize two of the new 1864 kW class of engines then being developed (Jumo 222 or Daimler Benz DB 604), with the Jumo 222 being specified for the great majority of such twin-engined designs, that Arado, Dornier, Focke-Wulf and Junkers had created airframe designs to use. The Arado
Ar E340 was eliminated. The Dornier Do 317 was put on a low-priority development contract; and the Junkers Ju 288 and Focke Wulf Fw 191 were chosen for full development.
Dipl. Ing E. Kösel, who also worked on the Fw 189
reconnaissance
plane, was supposed to have led the design team for the Fw 191. Overall, the Fw 191 was a clean, all-metal aircraft that featured a shoulder-mounted wing. Two 24-cylinder Jumo 222 engines (which showed more promise than the DB 604 engines) were mounted in nacelles on the wings. An interesting feature was the inclusion of the Multhopp-Klappe, an ingenious form of combined landing flap
and dive brake
, which was developed by Hans Multhopp
. The entire fuel supply was carried in five tanks located above the internal bomb bay
, and in two tanks in the wing between the engine nacelles and fuselage
.
The tail section was of a twin fin
s and rudder
s design, with the tailplane
having a small amount of dihedral. The main landing gear
legs retracted to the rear and rotated 90° to lie flat in each engine nacelle, much like the main gear on the production versions of the Ju 88
already did. Also, the tailwheel retracted forwards into the fuselage. A crew of four sat in the pressurized cockpit
, and a large Plexiglas dome was provided for the navigator; the radio operator could also use this dome to aim the remotely-controlled rear guns.
The Fw 191 followed established Luftwaffe practice in concentrating the crew in the nose compartment, and in the use of a "stepless cockpit", having no separate windscreen for the pilot, as the later -P and -H versions of the Heinkel He 111
already did. This was pressurised for high-altitude operations. The proposed operational armament consisted of one 20 mm MG 151 cannon
in a chin turret
, twin 20 mm MG 151 in a remotely controlled dorsal turret, twin 20 mm MG 151 in a remotely-controlled ventral turret, a tail turret with one or two machine gun
s and remotely-controlled weapons in the rear of the engine nacelles. However, different combinations were mounted in the prototype aircraft. Sighting stations were provided above and below the crew compartment.
The aircraft had an internal bomb bay. In addition, bombs or torpedo
es could be carried on external racks between the fuselage and the engine nacelles. The design was to have had a maximum speed of 600 km/h (370 mph), a bomb load of 4,000 kg (8,820 lb), and a range allowing it to bomb any target in Britain
from bases in France
and Norway
.
It is said that the installation of so many electric motors and wiring led to the nickname for the Fw 191 of "Das fliegende Kraftwerk" (the flying powerstation). This also had the detrimental effect of adding even more weight to the overburdened airframe, plus there was also the danger of a single enemy bullet putting every system out of action if the generator was hit. Dipl. Ing Melhorn took the Fw 191 V1 on its maiden flight early in 1942, with immediate problems arising from the lower rated engines not providing enough power, as was anticipated. One surprising problem that was encountered were the Multhopp-Klappe, which presented severe flutter problems when extended, and pointed to the need for a redesign. At this point, only dummy gun installations were fitted and no bomb load was carried. After completing ten test flights, the Fw 191 V1 was joined by the similar V2, but only a total of ten hours of test flight time was logged. The 1,864 kW (2,500 hp) Junkers Jumo 222 engines which would have powered the Fw 191 proved troublesome. In total only three prototype aircraft, V1, V2 & V6, were built. The project was crippled by engine problems and an extensive use of electrical motor-driven systems. Problems arose almost immediately when the Jumo 222 engines were not ready in time for the first flight tests, so a pair of 1193 kW BMW 801MA radial engine
s were fitted. This made the FW 191 V1 seriously underpowered. Another problem arose with the RLM's insistence that all systems that would normally be hydraulic or mechanically activated should be operated by electric motors.
At this point, the RLM allowed the redesign and removal of the electric motors (to be replaced by the standard hydraulics), so the Fw 191 V3, V4 and V5 were abandoned. The Fw 191 V6 was then modified to the new design, and also a pair of specially prepared Jumo 222 engines were fitted that developed 1641 kW for takeoff. The first flight of the new Fw 191 took place in December 1942 with Flugkapitän Hans Sander at the controls. Although the V6 flew better, the Jumo 222 were still not producing their design power, and the whole Jumo 222 development prospect was looking bad due to the shortage of special metals for it. The Fw 191 V6 was to have been the prototype for the Fw 191A series.
Since the Jumo 222 engines were having a lot of teething problems, and the Daimler Benz DB 604 had already been abandoned, a new proposal was put forth for the Fw 191B series.
The V7 through V12 machines were abandoned in favor of using the Fw 191 V13 to install a pair of Daimler Benz DB 606 or 610 engines, which were basically coupled pairs of either DB 601 or 605 12-cylinder engines. Their lower power-to-weight ratio, however, meant that the armament and payload would have to be reduced. It had already been decided to delete the engine nacelle gun turrets, and to make the rest manually operated. Five more prototypes were planned with the new engine arrangement, V14 through V18, but none were ever built, possibly from the August 1942 condemnation by Reichsmarschall Hermann Goering of the coupled "power system" DB 606 and 610 powerplants as "welded-together engines", in regards to their being the primary cause of the unending series of powerplant problems in their primary use, as the engines on Heinkel's He 177
, Germany's only production heavy bomber of World War II.
One final attempt was made to save the Fw 191 program, this time the Fw 191C was proposed as a four engined aircraft, using either the 999 kW Jumo 211F, the 969 kW DB 601E, the 1099.9 kW DB 605A or the 1099.9 kW DB 628 engines. Also, the cabin would be unpressurized and the guns manually operated; a rear step in the bottom of the deepened fuselage being provided for the gunner.
Unfortunately, at this time, the whole "Bomber B
" program had been canceled, due mainly to no engines of the 1,864 kW (2,500 hp) class being available, which was one of the primary requirements in the "Bomber B" program. Although the Fw 191 will be remembered as a failure, the air frame and overall design eventually proved themselves to be sound, only the underpowered engines and insistence on electric motors to operate all the systems eventually dooming the aircraft. All in all, there were only three Fw 191s ever built (V1, V2 and V6), and no examples of the Fw 191B or C ever advanced past the design stage. The project was eventually scrapped.
Focke-Wulf
Focke-Wulf Flugzeugbau AG was a German manufacturer of civil and military aircraft before and during World War II. Many of the company's successful fighter aircraft designs were slight modifications of the Focke-Wulf Fw 190.-History:...
Fw 191 was a prototype
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
German
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...
of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Two versions were intended to be produced, a twin-engine version using the Junkers Jumo 222 engine and a four-engine variant which was to have used the smaller Daimler-Benz DB 605
Daimler-Benz DB 605
|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9* Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1989. ISBN 0-517-67964-7...
engine. The project was eventually abandoned due to technical difficulties with the engines.
Design and development
In July 19391939 in aviation
This is a list of aviation-related events from 1939:-Events:* Kawasaki Heavy Industries transfers its aircraft engine production business to its subsidiary, the Kawasaki Aircraft Engineering Company Ltd....
, the RLM issued a specification for a high-performance medium bomber
Medium bomber
A medium bomber is a bomber aircraft designed to operate with medium bombloads over medium distances; the name serves to distinguish them from the larger heavy bombers and smaller light bombers...
(the "Bomber B
Bomber B
Bomber B was a German military aircraft design competition dating to just before the start of World War II to develop a second-generation high-speed bomber that would both be a direct successor to the Schnellbomber design philosophy, and to replace all medium and heavy bombers then in service with...
" program). It was to have a maximum speed of 600 km/h (370 mph) and be able to carry a bomb load of 4,000 kg (8,820 lb) to any part of Britain from bases in France or Norway. Furthermore, the new bomber was to have a pressurized
Cabin pressurization
Cabin pressurization is the pumping of compressed air into an aircraft cabin to maintain a safe and comfortable environment for crew and passengers when flying at altitude.-Need for cabin pressurization:...
crew compartment, of the then-generalized "stepless cockpit" design (with no separate windscreen for the pilot) pioneered by the He 111P
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...
shortly before the war and used on most German bombers during the war, remotely-controlled armament, and was to utilize two of the new 1864 kW class of engines then being developed (Jumo 222 or Daimler Benz DB 604), with the Jumo 222 being specified for the great majority of such twin-engined designs, that Arado, Dornier, Focke-Wulf and Junkers had created airframe designs to use. The Arado
Arado Flugzeugwerke
Arado Flugzeugwerke was a German aircraft manufacturer, originally established as the Warnemünde factory of the Flugzeugbau Friedrichshafen firm, that produced military hydroplanes during the First World War.-History:...
Ar E340 was eliminated. The Dornier Do 317 was put on a low-priority development contract; and the Junkers Ju 288 and Focke Wulf Fw 191 were chosen for full development.
Dipl. Ing E. Kösel, who also worked on the Fw 189
Focke-Wulf Fw 189
|-See also:-References:NotesBibliography* Brown, Capt. Eric . Wings of the Luftwaffe. Garden City, NY: Doubleday & Company, Inc., 1978. ISBN 0-385-13521-1....
reconnaissance
Reconnaissance
Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....
plane, was supposed to have led the design team for the Fw 191. Overall, the Fw 191 was a clean, all-metal aircraft that featured a shoulder-mounted wing. Two 24-cylinder Jumo 222 engines (which showed more promise than the DB 604 engines) were mounted in nacelles on the wings. An interesting feature was the inclusion of the Multhopp-Klappe, an ingenious form of combined landing flap
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
and dive brake
Dive bomber
A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target reduces the distance the bomb has to fall, which is the primary factor in determining the accuracy of the drop...
, which was developed by Hans Multhopp
Hans Multhopp
Hans Multhopp was a German aeronautical engineer/designer. Receiving a degree from the University of Göttingen, Multhopp worked with the famous designer Kurt Tank at the Focke-Wulf Flugzeugbau AG during World War II, and was the leader of the team responsible for the design of the Focke-Wulf Ta...
. The entire fuel supply was carried in five tanks located above the internal bomb bay
Bomb bay
The bomb bay or weapons bay on some military aircraft is a compartment to carry bombs, usually in the aircraft's fuselage, with "bomb bay doors" which open at the bottom. The bomb bay doors are opened and the bombs are dropped when over the target or at a specified launching point.Large-sized...
, and in two tanks in the wing between the engine nacelles and fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
.
The tail section was of a twin fin
Vertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
s and rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...
s design, with the tailplane
Tailplane
A tailplane, also known as horizontal stabilizer , is a small lifting surface located on the tail behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes...
having a small amount of dihedral. The main landing gear
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
legs retracted to the rear and rotated 90° to lie flat in each engine nacelle, much like the main gear on the production versions of the Ju 88
Junkers Ju 88
The Junkers Ju 88 was a World War II German Luftwaffe twin-engine, multi-role aircraft. Designed by Hugo Junkers' company through the services of two American aviation engineers in the mid-1930s, it suffered from a number of technical problems during the later stages of its development and early...
already did. Also, the tailwheel retracted forwards into the fuselage. A crew of four sat in the pressurized cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
, and a large Plexiglas dome was provided for the navigator; the radio operator could also use this dome to aim the remotely-controlled rear guns.
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...
already did. This was pressurised for high-altitude operations. The proposed operational armament consisted of one 20 mm MG 151 cannon
MG 151 cannon
The MG 151 was a 15 mm autocannon produced by Waffenfabrik Mauser starting in 1940. It was in 1941 developed into the 20 mm MG 151/20 cannon which was widely used on many types of German Luftwaffe fighters, fighter bombers, night fighters, ground attack and even bombers as part of or as...
in a chin turret
Gun turret
A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in many directions.The turret is also a rotating weapon platform...
, twin 20 mm MG 151 in a remotely controlled dorsal turret, twin 20 mm MG 151 in a remotely-controlled ventral turret, a tail turret with one or two machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
s and remotely-controlled weapons in the rear of the engine nacelles. However, different combinations were mounted in the prototype aircraft. Sighting stations were provided above and below the crew compartment.
The aircraft had an internal bomb bay. In addition, bombs or torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
es could be carried on external racks between the fuselage and the engine nacelles. The design was to have had a maximum speed of 600 km/h (370 mph), a bomb load of 4,000 kg (8,820 lb), and a range allowing it to bomb any target in Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
from bases in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
.
Failure and End of Program
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s were fitted. This made the FW 191 V1 seriously underpowered. Another problem arose with the RLM's insistence that all systems that would normally be hydraulic or mechanically activated should be operated by electric motors.
At this point, the RLM allowed the redesign and removal of the electric motors (to be replaced by the standard hydraulics), so the Fw 191 V3, V4 and V5 were abandoned. The Fw 191 V6 was then modified to the new design, and also a pair of specially prepared Jumo 222 engines were fitted that developed 1641 kW for takeoff. The first flight of the new Fw 191 took place in December 1942 with Flugkapitän Hans Sander at the controls. Although the V6 flew better, the Jumo 222 were still not producing their design power, and the whole Jumo 222 development prospect was looking bad due to the shortage of special metals for it. The Fw 191 V6 was to have been the prototype for the Fw 191A series.
Since the Jumo 222 engines were having a lot of teething problems, and the Daimler Benz DB 604 had already been abandoned, a new proposal was put forth for the Fw 191B series.
The V7 through V12 machines were abandoned in favor of using the Fw 191 V13 to install a pair of Daimler Benz DB 606 or 610 engines, which were basically coupled pairs of either DB 601 or 605 12-cylinder engines. Their lower power-to-weight ratio, however, meant that the armament and payload would have to be reduced. It had already been decided to delete the engine nacelle gun turrets, and to make the rest manually operated. Five more prototypes were planned with the new engine arrangement, V14 through V18, but none were ever built, possibly from the August 1942 condemnation by Reichsmarschall Hermann Goering of the coupled "power system" DB 606 and 610 powerplants as "welded-together engines", in regards to their being the primary cause of the unending series of powerplant problems in their primary use, as the engines on Heinkel's He 177
Heinkel He 177
The Heinkel He 177 Greif was the only operational long-range bomber to be operated by the Luftwaffe. Starting its existence as Germany's first purpose-built heavy bomber just before the war, and built in large numbers during World War II, it was also mistakenly tasked, right from its beginnings,...
, Germany's only production heavy bomber of World War II.
One final attempt was made to save the Fw 191 program, this time the Fw 191C was proposed as a four engined aircraft, using either the 999 kW Jumo 211F, the 969 kW DB 601E, the 1099.9 kW DB 605A or the 1099.9 kW DB 628 engines. Also, the cabin would be unpressurized and the guns manually operated; a rear step in the bottom of the deepened fuselage being provided for the gunner.
Unfortunately, at this time, the whole "Bomber B
Bomber B
Bomber B was a German military aircraft design competition dating to just before the start of World War II to develop a second-generation high-speed bomber that would both be a direct successor to the Schnellbomber design philosophy, and to replace all medium and heavy bombers then in service with...
" program had been canceled, due mainly to no engines of the 1,864 kW (2,500 hp) class being available, which was one of the primary requirements in the "Bomber B" program. Although the Fw 191 will be remembered as a failure, the air frame and overall design eventually proved themselves to be sound, only the underpowered engines and insistence on electric motors to operate all the systems eventually dooming the aircraft. All in all, there were only three Fw 191s ever built (V1, V2 and V6), and no examples of the Fw 191B or C ever advanced past the design stage. The project was eventually scrapped.
Specifications (Fw 191 V6, as designed)
- * In the original Focke-Wulf Fw 191 w/Jumo 222 factory documents this is the weight allocated for crew