Blohm & Voss BV 138
| Blohm & Voss BV 138 | |
|---|---|
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| Type: | Sea scout , flying boat |
| Design country: | |
| Manufacturer: | |
| First flight: |
July 15, 1937 |
| Commissioning: |
October 1940 |
| Production time: |
1938-1943 |
| Number of pieces: |
297 |
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The Blohm & Voss BV 138 was a successful long-range sea reconnaissance aircraft of the Luftwaffe , with which several sea reconnaissance squadrons were equipped. Because of the shape of its hull, the flying boat was nicknamed "Flying Wooden Shoe", which one unit, the 1. (F) / 130 (See), even made its relay badge.
development
In August 1934, the Reich Ministry of Aviation (RLM) issued a tender for a multi-engine sea long-range reconnaissance aircraft that was to be equipped with the newly developed, particularly economical Junkers Jumo 5 diesel engines (later designated 205). In addition to the plant, which was still operating as HFB at the time, these demands also went to the Dornier company . The new chief designer of the HFB, Richard Vogt , designed a three-engine flying boat with a central fuselage and double tail booms that featured two of his favorite ideas, the so-called tubular spar and the gull wing . The RLM obviously liked the design and was given the designation Ha 138. Already during the first attempts at taxiing on July 14, 1936 on a tributary of the Elbe near the Pagensand there was a rude awakening. The chief pilot, Helmut Wasa Rodig , was practically unable to get the prototype Ha 138 V1 (D-ARAK) out of the water. The further tests showed that the air flow on the upwardly bent inner wings was completely swirled. Vogt, supported by the test manager, Ing.Walter Stender , had to decide to replace the gull wing with a straight wing, which happened on the second aircraft. In addition, it was necessary to lengthen the hull at the rear by a full three meters, to make the tail boom much more torsion-resistant and to enlarge the surface of the rudder units.
With this second prototype Ha 138 V2 (D-AMOR), modified in this way, Rodig continued testing on July 23, 1937. At this time, the competition model Do 24 was already out of the running and the decision in favor of the Ha 138 had been made. The first aircraft of the pre-series, BV 138 A-01 (D-ADJE), finally met expectations. Due to further delays, the chief pilot was only able to take off on the first flight on July 11, 1939. So it came about that the Luftwaffe's maritime patrol squadrons had to go into the war with the Dornier Do 18 , which was only intended as a makeshift from the start . The A-01 was also the first aircraft to be designated with the new company abbreviation BV instead of Ha. It was followed by three more pre-series aircraft A-02 to A-04, until series production of 25 BV 138 A-1s started in January 1940. This was followed by 20 B-1 aircraft, followed by the large-scale production of 161 C-1s. Finally, Weser Flugzeugbau also received an order for 67 C-1 units. Production of the BV 138 stopped at the end of 1943.
commitment
The first deployment took place with the three pre-series aircraft BV 138 A-01 to 03 as troop transports during the Weser Exercise company , the occupation of Norway. One of the aircraft was shot at by its own anti-aircraft gun as it was still completely unknown and badly damaged, it was forced to make an emergency landing in the port of Bergen . This was clarified on the basis of the air force uniforms of the flying crews at the See trial site . The same also applied to the two existing Dornier Do 24 V1 and V2. During the remainder of the war, the BV 138 then served as a reconnaissance aircraft over the North and Baltic Seas as well as the English Channel and the Arctic Ocean . However , it had proven completely unsuitable for use at sea , but thanks to the continued Dutch and later also French production, the Do 24, which was initially rejected, could be used in a far superior way. Some BV 138 were also used for mine clearing, whereby the strong magnetic field generated by an aluminum ring attached under the aircraft caused sea mines equipped with magneto ignition to explode when flying low . Aircraft equipped with FuG 200 Hohentwiel were also used to fight submarines . The diesel engines also opened up the possibility of taking over fuel from German submarines far out in the Atlantic at an agreed point, which, however , had to be freed of the condensation water it contained on board prior to use .
The BV 138 also showed good combat characteristics compared to other machines thanks to its strong defensive armament. A Consolidated PBY Catalina and a Bristol Blenheim Mk. V were shot down by flying boats of this type .
One of the most famous pilots of this type of aircraft was the later CDU chairman Rainer Barzel .
Executions
- BV 138 A-1 : first series version with 605 hp Jumo 205 C engines and a 20 mm cannon in a rotating turret Lb 204 at the front and two open defensive posts, each with a 7.92 mm MG 15 at the rear.
- BV 138 B-1 : structurally reinforced version with 880 hp Jumo 205 D engines, two 20 mm MG 151/20 in hydraulic rotating ring mounts HD 151 / 1A in the bow and stern, the other MG 15 in the upper stern was soon added replaced by the 13 mm MG 131 .
- BV 138 C-1 : Reinforced version, the middle engine got a four-blade propeller due to damage , while the outer engines got three-blade propellers with wider blades.
- BV 138 MS : Minesweeping version, the armament was removed in order to be able to install the drive unit for the minesweeping equipment.
Technical specifications
| Parameter | Data (BV 138 C-1) |
|---|---|
| Type | ejectable reconnaissance flying boat |
| length | 19.90 m |
| span | 26.94 m |
| height | 6.60 m |
| Wing area | 112 m² |
| Wing extension | 6.5 |
| Empty mass | 8,100 kg |
| Max. Takeoff mass | 17,650 kg (for spin start) or 18,150 kg when starting with smoking devices (including 500 kg for the RG to be thrown) |
| Engine | three Junkers two-stroke diesel engines Jumo 205 D each with 648 kW (880 PS) starting power |
| fuel | 5,310 l in three protected containers and in three unprotected (in the tubular spar) |
| Top speed | 275 km / h |
| Cruising speed | 235 km / h |
| Service ceiling | 4,200 m |
| Range | 3,880 km |
| Flight duration | 6.5 h |
| Armament | two 20-mm-MG 151/20 one 13-mm-MG 131 initially three, later six 50-kg bombs or four 150-kg depth charges |
See also
literature
- Documentation by Theodor Mohr, Die BV 138 , in the magazine modell magazin, issue 5/1977.
- New and expanded version of this documentation in issue 6/06 of the Jet & Prop magazine
Web links
