Blohm & Voss BV 222

The Blohm & Voss BV 222 Wiking (pronounced "Veeking") was a large six-engined German flying boat designed and built by the German aircraft manufacturer Blohm & Voss. It was the largest flying boat to attain operational status during the Second World War.

The BV 222 was originally developed during the late 1930s as a commercial venture to serve the transatlantic and other long distance routes of the German flag carrier Luft Hansa. It featured a relatively uninterrupted interior, free of bulkheads, and retractable floats; its use of diesel-powered engines made it easier to be refuelled at sea. By the time of its maiden flight on 7 September 1940, Nazi Germany was almost one year into the Second World War and the operation of long distance civil services was not realistic, thus development was reorientated towards military roles. On 10 July 1941, V1 undertook its first cargo transport mission with the Luftwaffe; further logistics use proceeded thereafter. Later that year, the first armed BV 222s were delivered. Production standard aircraft, designated BV 222C, did not emerge until 1943.

The BV 222 was operated by the Luftwaffe, typically for logistical purposes, across numerous theatres, including the Norway, France, North Africa and even the Arctic. At one point, Nazi officials were considering establishing a long distance air route between Germany and Japan using modified BV 222s flying from Kirkenes in north Norway to Tokyo via Sakhalin Island, a distance of 6400 km. After the Allied Invasion of Normandy in June 1944, all of the remaining BV 222s were transferred to KG 200. At the end of the conflict, several BV 222s were reportedly captured and subsequently operated by both the United States and Britain; they were allegedly studied and influenced the design of future flying boats. No BV 222s have been preserved.

Development
During the interwar period, the German flag carrier Deutsche Luft Hansa had built up a lucrative network of long range airmail routes, the longest of which included transatlantic ones. During the mid 1930s, the airline continued to hold a strong interest in the further development of its long distance routes; accordingly, Luft Hansa formulated a requirement for a new large flying boat to serve on its transatlantic routes. Specifics of this requirement included sufficient space to accommodate a minimum of 24 passengers. In response, the German aircraft manufacturer Hamburger Flugzeugbau decided to design a new larger flying boat, which was initially designated the Ha 222; the company's design team was headed by Dr. Richard Vogt.

During September 1939, the company, which had changed its name to that of its parent company, Blohm & Voss, received an initial order from Luft Hansa for three aircraft under the new designation of BV 222. Blohm & Voss had been so confident that it would receive such an order that it had already elected to commence production of the first aircraft in January 1938, as well as to start work on two more aircraft later that same year.

On 7 September 1940, the first aircraft, designated V1, performed its maiden flight, carrying the civil registration D-ANTE. By this point, the Second World War had been waged for almost a whole year and Luft Hansa saw no prospect of operating a transatlantic route at a time of open hostilities, thus the airline had no immediate role for the BV 222 to perform. Accordingly, the flight test programme was adjusted to investigate the type's potential for military applications; various minor modification, such as the addition of larger loading doors, were promptly made.

Initial trials found that the BV 222 had relatively stiff flight controls and that its hydrodynamic qualities could be improved; the former issue was largely attributed to friction and thus was readily addressed. Those same trials also demonstrated that the aircraft was capable of carrying up to 92 passengers, or 72 stretcher-bound patients, over a short distance at a maximum speed of 385 km/h. The flight characteristics were determined to be satisfactory, although some improvements were required. Further trials of the aircraft lasted until December 1940, at which point the V1 was transferred to the Luftwaffe. It received a military paint scheme and the Stammkennzeichen individual alphabetic military aircraft registration code of CC+EQ, which was later changed to the alphanumeric Geschwaderkennung "wing code" designation of X4+AH, when in service with Lufttransportgruppe (See) 222.

Early aircraft were identified as V1 to V8. Production examples were designated C-09 to C-13. Up to two BV 222s could be assembled at a time at the company's Steinwerder works outside Hamburg; each complete airframe took an average of 350,000 man hours to construct. At the height of production, personnel worked night and day, permitting a hull to be completed within as little as six weeks.

Design
The Blohm & Voss BV 222 was a sizable six-engined flying boat. The interior volume of the hull was particularly spacious due to there being no partitioning bulkheads present above the floor level; the area between the keel and the cabin floor had close-pitched bulkheads instead. There were no heavy structural elements needed to carry stresses between the base of the hull and the wings. Access to the bilge was achieved via manholes. The planing bottom of the hull featured an unfaired and transverse main step. A further five smaller steps were present on the planing bottom, while the rear of the keel terminated in a deep knife-edge. To prevent the corrosion issues experienced with the first prototype, a specially-developed paint was applied to most BV 222s; unlike most flying boats, a high-quality surface finish was deemed to be unnecessary.

Typical amongst flying boats of the era, the BV 222 incorporated balance floats; unusually, these consisted of a matching pair of retracting float units per side, which extended from beneath the wing's outer panels in a "clamshell" fashion when fully extended, and retracted into recesses within the underside of the wing. While not originally present, flutes were added to sides of the floats to improve their hydrodynamic properties. The structure of the wing comprised a welded tubular steel wing spar; the engines were also supported by this same spar. This spar was of a constant section up to the outermost engine, after which it tapered towards the wingtips. Both fuel and oil were housed in separate compartments within the wing spar. In response to feedback from formal evaluations, the outer wing structure was strengthened somewhat over that of the original design.

The majority of the flight control surfaces, save for segments of the elevators that were power-augmented, was manually actuated by the pilot. On production aircraft, an arrangement of torsion tubes, gears and quadrants were used instead of push-pull rods to actuate the control surfaces. The ailerons were divided into two sections, the inner of which being fitted with servo tabs. Under normal operational conditions, the inner and outer aileron sections would move and work together, however, the inner sections would be picked up by stops on the outer sections in situations where they became ineffective, such as during low speed flight or taxiing downwind. The elevator was split into three sections, the outer one being used only for trimming, the inner section was directly controlled by the pilot, while the centre section was operated by an autopilot; the latter function was considered particularly useful for reducing operator fatigue during long distance flights, but was switched off during the landing and takeoff phases of the flight. Instead of the conventional three trimming wheels, a tab box was designed for the aircraft; it was highly praised by pilots.

The BV 222 was originally powered by an arrangement of six Bramo 323 Fafnir radial engines. Later built aircraft were powered by six 746 kW (1,000 hp) Jumo 207C inline two-stroke opposed-piston diesel engines instead. The use of diesel fuel permitted refueling at sea by special re-supply U-boats. A single aircraft, C-13, was the only example to be fitted with Jumo 205C and later Jumo 205D engines.

Operational history


On 10 July 1941, V1 undertook its first cargo transport mission for the Luftwaffe. Up to 19 August 1941, V1 performed seven flights between Hamburg (Germany) and Kirkenes (Norway), transporting a total of 65000 kg of supplies and 221 wounded men, covering a distance of 30000 km in total. After undergoing an overhaul at Hamburg, V1 was sent to Athens (Greece), from where it carried supplies for the Afrika Korps, making 17 flights between 16 October and 6 November 1941. At this time, V1 was unarmed, and thus received an escort by a pair of Messerschmitt Bf 110 heavy fighters.

Following these flights, V1 returned to Hamburg to have defensive armament fitted, comprising a 7.92 mm (.312 in) MG 81 machine gun in the hull, two turret-mounted 13 mm (.51 in) MG 131 machine guns, and four 7.92 mm (.312 in) MG 81s in waist mounts. The registration was changed to X4+AH at the same time and V1 formed the basis for the new air transport squadron Lufttransportstaffel 222 (LTS 222). Between 1942 and 1943, the aircraft flew in the Mediterranean theatre, until it sank following a collision with a submerged wreck while landing at Piraeus harbour in mid-February 1943.

On 7 August 1941, V2 (CC+ER) made its first flight; following a period of extensive testing, it was assigned to LTS 222 on 10 August 1942 as X4+AB. Since the aircraft was intended for long-distance overwater flights, in addition to the armament fitted to V1, it received two rear-facing wing-mounted turrets with dual 13 mm (.51 in) MG 131s, which were accessed via the tubular wing spar. These wing-mounted turrets were not present on the majority of BV 222 after it was determined that they negatively impacted overall aerodynamic performance.

Following the German invasion of the Soviet Union in June 1941, plans were made to connect Germany and Japan by air using Luftwaffe aircraft modified for very long range flights since commercial flights to the Far East by Deutsche Luft Hansa were no longer possible, and it had become very dangerous for ships or U-boats to make the trip by sea. Field Marshal Erhard Milch authorized a study in to the feasibility of such direct flights and various routes were considered, including departing from German-occupied Russia and Bulgaria, and a sea route using a BV 222 flying from Kirkenes in north Norway to Tokyo via Sakhalin Island, a distance of 6400 km. The BV 222 was one of three aircraft considered seriously for the program, along with the Focke-Wulf Fw 200 and the Heinkel He 177. The He 177 was ruled out due to it being considered unreliable and in 1943 the Junkers Ju 290 was selected for the flights.

On 28 November 1941, V3 (initially DM+SD) first flew, it was transferred to LTS 222 on 9 December 1941. After V1's sinking, V3 returned to Hamburg where it was armed. It was destroyed along with V5 on 20 June 1943 at Biscarrosse by RAF de Havilland Mosquitos of No. 264 Squadron.

V4, which had an altered height tail, was also assigned to LTS 222 for Africa flights. V6 was shot down on 21 August 1942 on the Taranto (Italy) to Tripoli (Libya) route by a Bristol Beaufighter; V8 was shot down on the same route on 10 December 1942.

By late 1942, German officials had become increasingly interested in deploying the BV 222 as a long range maritime patrol aircraft and less as a transport. Accordingly, future refits commonly saw the addition of the FuG 200 Hohentwiel search radar, rear warning systems, and armament changes. Somewhat related to these changes was V7 (TB+QL), which made its first flight on 1 April 1943. In addition to the aforementioned changes, V7 was fitted with six 746 kW (1,000 hp) Jumo 207C inline two-stroke diesel engines. With a takeoff weight of 50000 kg and a range of 6100 km. it was intended as the prototype BV 222C.

One BV 222, V4, is reported to have shot down a US Navy PB4Y-1 Liberator of VB-105 (BU#63917) on 22 October 1943. On occasion, this event has often been mistakenly construed as a BV 222 shooting down an Avro Lancaster.

A BV 222, believe to have been C-10, reportedly shot down southwest of Biscarrosse on the night of 8 February 1944 by an RAF Mosquito of No. 157 Squadron. During 1944, V2 participated in Operation Schatzgräber ("Treasure Seeker"), the code name of a German weather station at Alexandra Land in the Arctic, whose sick crew needed to be evacuated. The BV 222 dropped a spare wheel for a Fw 200 which had sustained damage during landing near the station.

Following the Invasion of Normandy in June 1944, the remaining BV 222s were transferred to KG 200. Of these, C-09 was probably the BV 222 reported to have been strafed and destroyed by RCAF Hawker Typhoon aircraft of No. 439 Squadron on 24 April 1945 at Seedorf. V7 and V4 were scuttled by their crews at Travemünde and Kiel-Holtenau airport respectively, at the end of the conflict.

Postwar
Three BV 222s were captured and subsequently operated by Allied forces: C-011, C-012 and C-013. C-012, which was captured at Sørreisa in Norway after the end of the conflict along with V2, was flown by Captain Eric "Winkle" Brown from Norway to the RAF station at Calshot in 1946, the aircraft being assigned the RAF serial number "VP501". After it was tested by the Marine Aircraft Experimental Establishment at Felixstowe, it was assigned to No. 201 Squadron, which operated VP501 up to 1947, at which point the aircraft was scrapped.

At the end of the Second World War, both C-011 and C-013 had been captured by US forces at the end of the conflict. On 15 August and again on 20 August 1945, US Navy pilot Richard Schreder performed test flights, accompanied by a German flight crew, of one of these captured BV 222s. Across two flights, covering a total flight time of 38 minutes, no less than four engine fires were recorded. While many spare engines were available, they were of substandard quality due to the lack of quality alloys near the end of the conflict, and thus caught fire easily. Since the aircraft was not airworthy with these engines, the aircraft was taken out to open water and sunk by a US Navy destroyer.

Other reports indicate the US captured aircraft were flown or shipped to the US. Convair allegedly acquired one for evaluation at the Naval Air Station Patuxent River, the intensive studies leading to the hull design of their Model 117, which in turn led to the R3Y Tradewind. Their subsequent fate is unknown.

The V2 aircraft briefly wore US markings in 1946. The V2 aircraft had identification markings from the original V5 aircraft for Operation Schatzgräber. V2 was later scuttled by the British who filled it with surplus waste from the base at Ilsvika to weigh it down. V2 was towed to a position in Trondheimsfjord between Ilsvika and Munkholmen, where it now rests on the seabed at 318 m deep, perfectly preserved due to low oxygen levels in the water. There were plans to raise and restore this aircraft. However, the plane was located in October 2023 by the firm Blueye Robotics, and they published video of the wreck. Signs now indicate nature is slowly breaking down the aircraft, and that coral can be seen growing on the plane. Historian Knut Sivertsen, advisor at Justismuseet in Trondheim stated in 2023 that the plane is probably too big to salvage, and there are no plans to do so at the present time.

Variants

 * BV 222A : Prototype aircraft.
 * BV 222B : Proposed version powered by 1470 hp (1100 kW) Junkers Jumo 208 diesel engines.
 * BV 222C : Production aircraft.