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BLOCH MB174

 


Technical Specifications
Type
Twin-Engine of reconnaissance three-seater with low-wings and retractable landing gear
Date first flight
February 15, 1938
Wingspan
17,80 m 
Lenght
12,15 m 
Height
3,55 m 
Wing Area
37,63 m2 
Empty Weight
5600 Kg 
Max. Takeoff Weight
7160 Kg 
Cruising Speed
400 km/h. 
Maximum Speed
529 km/h at 5200m 
Climbing Speed
8000m in 11mn  
Service ceilling
11000m 
Range
1290 kms 
Crew
3 Men
Motorization
2 Radial Engine Gnôme Rhône 14 cyl 14N48/49 air-cooled of 1140ch each
Armament

2 machine-guns MAC 34 of 7.5mm in the wings with 1000 rounds per gun
2 twin-machine-guns MAC 34 of 7.5mm in rear defense
3 machine-guns MAC 34 of 7.5mm in ventral position
400 Kgs of bombs

 


Production

88 Bloch of the MB 170 serie, were built after the prototype that made its first flight on February 15, 1938 . They are divided in :

  • 2 Bloch MB 170 : prototype n°01 and 02 of the serie
  • 1 prototype MB 174 n°01
  • 6 Exemplaries of MB174 of pre-series
  • 50 MB 174 of serie
  • 1 prototype MB 175 n°01
  • 23 MB 175 of serie
  • 5 Bloch MB 176

To date, out of the 88 aircraft manufactured , 30 are listed in the list below :

 


Historical

The Bloch MB174 was designed to respond to a program issued at the end of 1936 for the supply of combat multi-seater. At that time, the company BLOCH has just been absorbed by SNCASO, a company created by the Nationalizations of French Aeronautical Enterprises. The SNCASO design office therefore proposes a multi-seater twin-engine: the BLOCH MB170 n ° 01 which made its first flight on 15 February 1938.

This aircraft is in the form of a twin-engine of reconnaissance with double drift and wide window. This one, placed very in front of the fuselage, can acceuillir 3 people. It is motorized by 2 Gnôme-Rhône 14 N 6/7. It has a small bomb bay and its armament consists of a 20mm cannon in the nose, two 7.5mm machine guns in the wings and two others in the back. It carries the photographic material in a ventral gondola. The aircraft, accidented on March 17, 1938, is replaced by the n ° 02 designed like a bomber. This one loses its ventral gondola and its nose is at half vitreous.

The official services ultimately give priority to the model of strategic recognition that becomes the Bloch MB174 whose prototype flew on January 5, 1939. It differs from the Bloch MB170 by a receded glass and its nose completely glazed. It is now powered by Gnome-Rhone GR 14N-20/21. The device proved to be very fast, flying 100km / h faster than a Potez 63-11 for example! The first contract is signed on 1 February 1939 for 6 aircraft of pre-series and 50 aircraft of series. The first models (No. 07), which flew on November 5, 1939, were fitted with Gnome-Rhone 14 N-48/49, which, combined with propulsion exhaust manifolds, further increased performance. As is often the case, the deliveries of the aircraft in units were much delayed and by May 10, 1940, only 52 out of the 271 finally ordered, will be delivered. The GR II / 33 was the first unit to receive the new aircraft and one of the first flights will be made on 29 March 1940 by Captain de Saint-Exupéry, which will be recounted in his book "Pilote de Guerre". On mission, the speed of the aircraft put him out of the German hunt which had great difficulty in intercepting him. At the Armisitice, 25 copies were collected, the majority of which were gathered in the GR II / 33 based in Tunis and some of them will fight under the colors of the France-Libre in 1942. The Germans also seized a few copies for their training schools.

The qualities of the device are such that a version of Bombardment is quickly imagined: the bloch MB175. Thus, the assembly of Bloch 174 is stopped as of the 50th copy to leave room for MB175. The latter has an enlarged bomber bay. To do this, it was necessary to review the design of the wing by moving the side members. The apparatus thus modified has lengthened by 15 cm and sees its wing surface enlarged. The first prototype flew in December 1939. A variant is also studied to remedy the lack of French engines reserved for hunters. US engines Pratt & Whitney Twin Wasp are used to replace the Gnome-Rhone: the device thus equipped becomes the Bloch MB176. A first command was passed on the delivery of 814 MB175 and 323 MB176. The first series aircraft (No. 101) took off in April 1940. Although it is a reconnaissance group, it is the GR II / 52 which receives 12 machines of this type, the GAO 510 receiving 2 others. Before the Armistice, the GR II / 52 retreated to the AFN with its aircraft and will be based in Oran until the arrival of the Allied Forces in 1942.

As for the Bloch MB176, the first serial aircraft (No. 201) was released from the assembly lines in May 1940 and only 5 Bloch MB176 were delivered before Armisitice.

Many Bloch MB175 cells in the course of assembly will be seized by the Germans. They will continue manufacturing to equip the German pilot schools.

 


Versions

Bloch MB170
Prototype built in two copies that served as a basis for derivatives. It is motorized by 2 Gnome Rhone 14-N-6/7. His armament consisted of a 20mm cannon in the nose, two 7.5mm machine guns in the wings and two others in the back.
Bloch MB174

Reconnaissance version, the first flight of which took place on January 5th, 1939. Compared to the MB170, the canopy is retracted and the nose is entirely glazed. The prototype n ° 01 is powered by Gnome Rhone GR14 N 20/21 of 1030hp. Subsequently, the 6 pre-series aircraft received Rhone 14 N48 / 49 from 1140hp with propulsion exhaust pipes. This motorization, more powerful, is adopted for the series. The arming abandons the cannon of 20mm..

Bloch MB175

Version of Bombardment which made its first flight on December 3, 1939. To accommodate a bomb bay of greater capacity, the fuselage is enlarged by 15cm, and the wing surface augments.

Bloch MB176
Version identical to the MB175, but powered by Pratt & Whitney R-1830 SC 3-G of 1050 hp..


Bibliography

1 ) _ "Le Bloch 174 et ses dérivés"

 

1) _ Editions Larivière :
- Le Fanatique de L'Aviation : N°14-15-16

 

 

 


Photos Album

 


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