Blohm & Voss BV 138

https://en.wikipedia.org/wiki/Blohm_%26_Voss_BV_138

The Blohm & Voss BV 138 Seedrache (Sea Dragon), but nicknamed Der Fliegende
Holzschuh ("flying clog", from the side-view shape of its fuselage) was a World
War II German trimotor flying boat that served as the Luftwaffe's main seaborne
long-range maritime patrol and naval reconnaissance aircraft.

A total of 297 BV 138s were built between 1938 and 1943.

Originally developed under the company name of Hamburger Flugzeugbau, the type
was initially designated the Ha 138. Its appearance was unique in its
combination of unusual design features with its twin boom tail unit, short
fuselage and trimotor engine configuration. The short hull, with its
hydrodynamic step beneath and flat sides, earned it the nickname, "Fliegender
Holzschuh" (the flying clog).

Three piston engines were used. The central engine was mounted above the wing,
driving a four-blade propeller, while the wing engines were lower, with
three-blade propellers. The pre-production prototypes and the BV 138 A-01 to BV
138 A-06, were powered by various makes of engines ranging from 485–746 kW
(650–1,000 hp). The first standardized version, BV 138 B-1, was powered by three
880 PS (868 hp, 647 kW) Junkers Jumo 205D two-stroke, opposed-piston aircraft
diesel engines. The engine cowlings also had an atypical appearance, due to the
unique nature of the vertical orientation of the six-cylinder opposed-piston
Jumo 205 diesel engines, and resembled the cowlings of 4 or 6-cylinder inverted
inline engines found on smaller civil and utility aircraft from the Jumo 205's
propshaft placement, emerging forward at the uppermost front end of the
powerplant.

The booms of the twin tail unit, much like the smaller Focke-Wulf Fw 189
twin-engined reconnaissance monoplane, extended horizontally from the rear of
the outer engine nacelles.

For hydrodynamic reasons, the hull featured a distinct "turn-down", or "beak" at
the stern.

Two enclosed, powered gun turrets, each mounting a single MG 151/20 autocannon,
were located prominently at the bow and stern. A third, fully open Scarff
ring-like emplacement, behind the central engine and both above and forward of
the rear turret, mounted a 13 mm MG 131 heavy machine gun covered fields of fire
obstructed from the other turrets by the horizontal stabilizer.


Role
Maritime patrol
Long-Range Reconnaissance

Manufacturer
Blohm & Voss

Designer
Richard Vogt

First flight
15 July, 1937

Introduction
October, 1940

Primary user
Luftwaffe

Produced
1938–1943

Number built
297

In all, 227 examples of standard service variants of the BV 138 were built. The
first such variant, BV 138 C-1, began service in March 1941. While non-standard
variants carried a variety of armament, the standard variant featured two 20 mm
MG 151/20 cannon, one in a power-operated bow turret and one in a power-operated
stern turret, up to three 7.92 mm MG 15 machine guns, and a 13 mm (.51 in) MG
131 machine gun in the aft center engine nacelle. It could carry up to 500 kg
(1,100 lb) of bombs or depth charges (under the starboard wing root only) or, in
place of these, up to 10 passengers.

Both the B-1/U1 and C-1/U1 variants had racks under both wings to double the
offensive load.

Some examples of the BV 138 were adapted to specialized roles. The Bv 138 was
tested with the oft-used Walter HWK 109-500 Starthilfe RATO jettisonable rocket
pod, used in pairs, for shorter takeoff performance. One anti-shipping variant
carried FuG 200 Hohentwiel low-UHF band maritime search radar. The BV 138 MS
variant was converted for minesweeping, and carried magnetic field-generating
degaussing equipment, including a hoop antenna with a diameter equal to the
length of the fuselage, which encircled the hull and wings, which was also used
on certain models of the Ju 52/3m trimotor transport used for the same duty.

Specifications (BV 138 C-1)

General characteristics
Crew: 6 (pilot, navigator, radio operator, nose-gunner, rear-gunner, upper-rear
gunner)
Capacity: up to 10 passengers
Length: 19.85 m (65 ft 1 in)
Wingspan: 26.94 m (88 ft 5 in)
Height: 5.9 m (19 ft 4 in)
Wing area: 112 m2 (1,210 sq ft)
Empty weight: 11,770 kg (25,948 lb)
Gross weight: 14,500 kg (31,967 lb)
Max takeoff weight: 17,650 kg (38,912 lb)
Fuel capacity: 3,750 l (990 US gal; 820 imp gal) maximum internal fuel
Powerplant: 3 × Junkers Jumo 205D 6-cylinder liqiuid-cooled opposed piston
diesel engines, 656 kW (880 hp) each for take-off
Propellers: 3-bladed constant-speed propellers

Performance
Maximum speed: 285 km/h (177 mph; 154 kn) at sea level at 14,000 kg (30,865 lb)
at sea level
Cruise speed: 235 km/h (146 mph; 127 kn) at 1,000 m (3,281 ft)
Range: 1,220 km (758 mi; 659 nmi) at 195 km/h (121 mph; 105 kn)
Ferry range: 4,300 km (2,672 mi; 2,322 nmi) with max fuel
Endurance: 6 hours 30 minutes normal ; 18 hours maximum
Service ceiling: 5,000 m (16,000 ft) at 14,500 kg (31,967 lb)
2,800 m (9,186 ft) at 17,650 kg (38,912 lb)Rate of climb: 3.67 m/s (722 ft/min)
Time to altitude: 3,170 m (10,400 ft) in 24 minutes
Wing loading: 114.2 kg/m2 (23.4 lb/sq ft)
Power/mass: 0.106 kW/kg (0.064 hp/lb)

Armament

Guns:

2 × 20 mm (0.787 in) MG 151 cannon, one in a nose turret and one in the rear
fuselage covering upper rear area
1 × 13 mm (0.512 in) MG 131 machine gun in open position behind the central
engine, covering the top rear area
1–3 × 7.92 mm (0.312 in) MG 15 machine guns (optional)
Bombs: :* up to 6 × 50 kg (110.2 lb) bombs or 4 × 150 kg (330.7 lb) depth
charges under starboard wing root only (optional)




*