Heinkel He 51

https://en.wikipedia.org/wiki/Heinkel_He_51

The Heinkel He 51 was a German single-seat biplane which was produced in a
number of different versions. It was initially developed as a fighter, a
seaplane variant and a ground-attack version were also developed. It was a
development of the earlier He 49.

In 1931, Heinkel recruited the talented aircraft designers Walter and Siegfried
Günter. Their first major design for Heinkel was the Heinkel He 49. While this
was officially an advanced trainer, in fact it was a fighter. The first
prototype, the He 49a, flew in November 1932, and was followed by two further
prototypes, the He 49b, with a longer fuselage, and the He 49c, with a revised
engine.

The type was ordered into production for the still secret Luftwaffe as the He
51, the first pre-production aircraft flying in May 1933. Deliveries started in
July of the next year.

The He 51 was a conventional single-bay biplane, with all-metal construction and
fabric covering. It was powered by a glycol-cooled BMW VI engine, with an
armament of two 7,92 mm (.323 in) machine guns mounted above the engine.

The He 51 was intended to replace the earlier Arado Ar 65, but served
side-by-side with the slightly later Ar 68. The He 51 was outdated the day it
entered service, and after an initial run of 150 production fighters, the design
was switched into the modified He 51B, with approximately 450 built, including
about 46 He 51B-2 floatplanes, and then finally a further 100 He 51C light
ground-attack plane.


Role
Biplane fighter-bomber

Manufacturer
Heinkel

First flight
May 1933

Introduction
1935

Retired
1939 (Luftwaffe) 1952 (Spanish Air Force)

Status
Retired

Primary user
Luftwaffe

Number built
700

On 6 August 1936, six of the He 51s were delivered to Spain to fight in the
Spanish Civil War along with the faction of the army in revolt. Initial
operations were successful, with the Heinkels meeting and defeating a number of
older biplanes of the Spanish Republican Air Force, with two Nieuport Ni-52
fighters, a Breguet 19 and a Potez 54 destroyed on 18 August 1936, the first day
of operations by Spanish-flown He 51s. Deliveries continued as the hostilities
increased, with two Nationalist squadrons equipped by November, and the Legion
Condor forming three squadrons of 12 aircraft each manned by German
"volunteers".

This time of superiority was short lived, with the arrival of large numbers of
modern aircraft from the Soviet Union, including the Polikarpov I-15 biplane and
new Polikarpov I-16 monoplane, together with the Tupolev SB bomber, which was
110 km/h (70 mph) faster. The He 51 proved unable to protect the Legion Condor's
bombers, forcing it to switch to night operations, while also unable to
intercept the much faster SB. The He 51 was therefore withdrawn from fighter
duty and relegated to the ground-attack role by both the Legion Condor and the
Spanish rebels. It was replaced in the fighter role by the Fiat CR.32 in the
rebel Nationalist Air Force, with the Legion Condor receiving Messerschmitt Bf
109s from April 1937 to allow it to operate successfully in fighter operations.

While a failure as a fighter, the Heinkel proved successful as a ground-attack
aircraft, being used by Wolfram von Richthofen to develop the close support
tactics which were used by the Luftwaffe in World War II. It continued in use as
a ground attack aircraft for the remainder of the Civil War, although losses
were heavy. After the war the 46 surviving aircraft would be joined by another
15 new builds, and serve in the utility role in Spain until 1952.

The He 51 continued in front-line service with the Luftwaffe until 1938, with it
remaining in service as an advanced trainer for the first few years of World War
II.

Specifications (He 51B-1)

General characteristics
Crew: 1
Length: 8.40 m (25 ft 6¾ in)
Wingspan: 11.00 m (36 ft 1 in)
Height: 3.20 m (10 ft 6 in)
Wing area: 27.20 m² (292.6 ft²)
Empty weight: 1,460 kg (3,212 lb)
Loaded weight: 1,900 kg (4,180 lb)
Powerplant: 1 × BMW VI 7,3Z liquid-cooled V12 engine, 559 kW (750 hp)

Performance
Maximum speed: 330 km/h (178 kn, 205 mph)
Cruise speed: 280 km/h (151 kn, 174 mph)
Range: 570 km (308 nmi, 354 mi)
Service ceiling: 7,700 m (25,256 ft)
Wing loading: 69.9 kg/m² (14.3 lb/ft²)
Power/mass: 0.29 kW/kg (0.18 hp/lb)
Climb to 1,000 m (3,300 ft): 1.4 min
Climb to 6,000 m (19,700 ft): 16.5 min

Armament

Guns: 2 × 7.92 mm MG 17 machine guns in nose; 500 rpg
Bombs: 6 × 10 kg (22 lb) bombs (C-1)




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