Blohm & Voss BV 40

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BV 40
Profile view of the first prototype
Role fighter glider
Manufacturer Blohm & Voss
First flight 6 May 1944
Number built 6 prototypes completed

The Blohm & Voss BV 40 was a prototype armoured German glider initially designed in mid-1943 by Blohm & Voss to attack Allied bomber formations during World War II. The BV 40 would be towed to high altitude by other aircraft ahead of the bombers and then ram them while in a dive, but this concept was rejected before its first glide in May 1944. Development continued, although the glider's mission changed to attacking ships with very short-range torpedoes until it was cancelled in August with only six gliders completed.

Design and description[edit]

Conceived in mid-1943 by Richard Vogt, chief designer and technical director of Blohm & Voss, the BV 40 was to be towed by a Messerschmitt Bf 109 to high altitude[1] and released above the Allied bombers' combat box.[2] Once released, it would dive down at a sharp angle towards the enemy bomber fleet and ram the vertical stabiliser of a bomber, causing it to crash, and thus also to disrupt the close-flying bomber formation. The German Air Ministry (Reichsluftfahrtministerium) responded favourably to his proposal on 19 August and added a requirement for a single 30 mm (1.2 in) MK 108 cannon to neutralise the bomber's rear gunner. In order to minimise the aircraft's cross-section as a target for the gunner and improve the pilot's resistance to G-forces, he would lie in prone position since a 1940 study using centrifuges had estimated an increase from 5Gs to 12Gs.[3]

The German Aviation Research Institute (Deutsche Versuchsanstalt fuer Luftfahrt) had commissioned an small experimental aircraft, the Akaflieg Berlin B9, in 1942 to evaluate the engineering requirements of a powered aircraft with a prone pilot. Blohm & Voss engineers and pilots flew the aircraft in September 1943 to aid in the development of the BV 40. The following month Vogt wrote to the Air Ministry stating that further studies had shown that attacking from the rear was infeasible due to the extreme altitude required to gain the necessary speed to overtake the bombers. He also stated: "In view of the psychological difficulties [of a ramming attack] and the need to put considerable weight into ram-proof wings, we would like to propose... refraining from intentional ramming for the time being and sticking to close range shooting attacks as the task."[4]

A series of meetings in December with the Air Ministry and the Office of the Inspector of Fighters (Inspekteur der Jagdflieger) finalized the BV 40's configuration. The armament was increased to two MK 108 guns which were moved from the initial position on the top of the fuselage to wing-root pods and a Schlinge Device (Gerät Schlinge) was added. This was a 10-kilogram (22 lb) bomb towed behind the aircraft on a sharp 100–400-metre (330–1,310 ft) cable that was intended to be flown over an enemy bomber. Either the bomb would hit the bomber or the cable would snag it, potentially swinging the bomb into the bomber, and the cable would snap on impact.[5]

The glider was designed to use non-strategic materials and to be built in as short a time as possible by non-skilled workers..[6] It was of conventional layout, having a shoulder-mounted, straight untapered wooden wing with a similarly-shaped tailplane mounted part way up the vertical stabiliser. There was no conventional undercarriage as the aircraft was designed to use a one-axle trolley for take-off, to be dropped once the glider was airborne. A skid under the nose was lowered for landing.[7]

The fuselage of the first prototype was built in three sections of which only the aft fuselage was built from wood. The center section was made from sheet steel 0.8 millimetres (0.031 in) thick, although the pilot's legs were protected by 8-millimetre-thick (0.31 in) steel plates. It could be jettisoned from the forward section to allow the pilot to bail out. The cockpit occupied the forward fuselage and was entirely formed from flat armour plates with some wooden fairings to reduce aerodynamic drag. Two 20-millimetre-thick (0.8 in) plates covered the front of the cockpit; the lower plate was vertical, but the upper plate that angled backwards toward the pilot. The upper plate incorporated a windscreen of bulletproof glass 120 millimetres (4.7 in) thick. The sides consisted of 8-millimetre plates that included small glass windows that could be covered by sliding steel plates. Together with the windscreen, these gave the pilot a 35° view up and down and 20° from side to side. The floor of the cockpit consisted of a 5-millimetre (0.20 in) plate. To reduce magnetic deviation from the armour plates, the compass protruded from the aircraft's nose and could only be viewed by the pilot via mirrors.[8]

Although it was not originally intended as such,[9] during development the original role was abandoned and the BV 40 found a new potential role as a suicide weapon, carrying missiles under its wings in place of the cannon. For this role it was planned to develop a Mistel-style launch technique, carrying two BV 40s under the wings of a larger aircraft, but this was never implemented. Rocket propulsion was also considered, but was judged unsuitable.[10]

Development[edit]

Several prototypes were completed and flown, towed behind a Messerschmitt Bf 110. The BV 40 V1 (PN+UA) first flew in late May 1944.[11] It was found the craft could reach 292 miles per hour (470 km/h; 254 kn) and it was thought to have the potential to go far faster.[7] Various changes to the requirement and to the design were discussed, before the project was cancelled later in the year. In all, seven aircraft were completed and five of them flown.

Specifications (BV 40)[edit]

Data from Die Deutsche Luftrüstung 1933–1945: Vol. 1: AEG-Dornier[12]

General characteristics

  • Crew: 1
  • Length: 5.7 m (18 ft 8 in)
  • Wingspan: 7.9 m (25 ft 11 in)
  • Height: 1.63 m (5 ft 4 in)
  • Wing area: 8.7 m2 (94 sq ft)
  • Empty weight: 838 kg (1,847 lb)
  • Gross weight: 952 kg (2,099 lb)

Performance

  • Never exceed speed: 900 km/h (560 mph, 490 kn)
  • Landing speed: 125 km/h (78 mph; 67 kn)

Armament

See also[edit]

Related lists

References[edit]

  1. ^ Sharp, p. 60
  2. ^ Miranda, p. 35
  3. ^ Sharp, pp. 60–62
  4. ^ Sharp, p. 65
  5. ^ Sharp, pp. 65–66
  6. ^ Ford, p. 224
  7. ^ a b Mrazek, p. 315
  8. ^ Sharp, pp. 69–70, 72
  9. ^ "German Suicidal Aircraft". discaircraft. Retrieved 30 March 2019.
  10. ^ Sharp, p. 74
  11. ^ Munson 1978, p. 28.
  12. ^ Nowarra, pp. 119–120, 240–241

Bibliography[edit]

  • Ford, Roger (2013). Germany's Secret Weapons of World War II. London: Amber Books. ISBN 978-1-909160-56-9.
  • Green, William (1986) [1970]. The Warplanes of the Third Reich. New York: Galahad Books. ISBN 0-88365-666-3.
  • Miranda, Justo (2017). Axis Suicide Squads: German and Japanese Secret Projects of the Second World War. England: Fonthill Media. ISBN 978-1-78155-565-1.
  • Mrazek, James E. (2011). Airborne Combat: The Glider War/Fighting Gliders of WWII. Stackpole Books. ISBN 978-0-8117-4466-9.
  • Munson, Kenneth (1978). German Aircraft Of World War 2 in Colour. Poole, UK: Blandford Press. ISBN 0-7137-0860-3.
  • Nowarra, Heinz J. (1993). Die Deutsche Luftrüstung 1933–1945 (in German). Vol. 1: AEG-Dornier. Koblenz: Bernard & Graefe Verlag. ISBN 978-3-7637-5464-9.
  • Sharp, Dan (2023). Secret Projects of the Luftwaffe. Horncastle, UK: Tempest. ISBN 978-1-911703-28-0.

Further reading[edit]

  • Green, William & Swanborough, Gordon (2001) [1994]. The Complete Book of Fighters: An Illustrated Encyclopedia of Every Fighter Built and Flown (Revised and Updated ed.). London: Salamander Books. ISBN 1-84065-269-1.
  • Smith, J. Richard; Kay, Anthony (1978). German Aircraft of the Second World War. London: Putnam & Company. ISBN 0-370-00024-2.
  • Wood, Tony; Gunston, Bill (1977). Hitler's Luftwaffe: A Pictorial History and Technical Encyclopedia of Hitler's Air Power in World War II. Salamander Books. p. 138. ISBN 0-86101-005-1.

External links[edit]

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