Potez 630

The Potez 630 and its derivatives were a family of twin-engined aircraft developed for the Armée de l'Air in the late 1930s. The design was a contemporary of the British Bristol Blenheim (which was larger and designed purely as a bomber) and the German Messerschmitt Bf 110 (which was designed purely as a fighter).

Design and development
The original Potez 630 was built to meet the requirements of a 1934 heavy fighter specification which also resulted in the successful Breguet 690 series of attack aircraft. The prototype first flew in 1936 and proved to have excellent handling qualities.

The Potez 630 was a twin engine, monoplane, fully metallic three-seater with efficient aerodynamic lines and twin tailplanes. The long glasshouse hosted the pilot, an observer or commander who was only aboard if the mission required it, and a rear gunner who manned a single flexible light machine gun.

Only very minor changes were required and an order for 80 was placed in 1937. Simultaneously 80 Potez 631 C3 fighters were ordered, these having Gnome-Rhône 14M radial engines rather than the Hispano-Suiza 14AB10/11 of the Potez 630. Fifty additional Potez 631s were ordered in 1938 of which 20 were diverted to Finland, although they never reached that country.

Operational service
Production Potez 630 fighters started to be delivered from May 1938, with the Potez 631 following in August that year. Potez 630 and 631s, in two-seater configuration, were used to replace obsolete ANF Les Mureaux 113 used as night fighters, while single-seat fighter groups received a number of three seat Potez 63s to act as "command aircraft", from which formations of single-seat fighters would be directed and co-ordinated by radio. The Potez 630's engines proved so troublesome that most units had re-equipped with the Potez 631 before World War two began. The latter was an ineffectual interceptor, slower than some German bombers and 130 km/h slower than the Bf 109E, although it continued in service until the armistice.



The Armée de l'Air (French Air Force) placed an order for 125 Potez 633 light bombers in May 1938, with orders having also being placed by Romania and Greece for 20 and 24 Potez 633s respectively. France cancelled its order for Potez 633s in the summer of 1938, but further orders for the 633 were placed by Romania (for 20 more aircraft, which had been part built under the French order), and from China, for nine. Deliveries to Romania started late in 1938, with the Greeks receiving their first aircraft in the spring of 1939. In August 1939, with the risk of war increasing the French government requisitioned 32 Potez 633s from the Greek and Romanian orders that were still in France awaiting delivery.

France used these 633s as conversion trainers for units receiving the Breguet 691 attack aircraft. On 20 May 1940, three Potez 633s took part in a strafing mission against German troops near Arras. This was the types only operational mission over France as two days later the aircraft was withdrawn from front-line service. A small number of Potez 633 originally destined for China were commandeered by the French colonial administration in Indo-China and saw limited action in the brief French-Thai War in early 1941.

The Potez 633 exported to Greece and Romania saw more extensive service, in limited numbers. Greece had nine Potez 633s in service when Italy invaded Greece in October 1940. These were used for bombing attacks against Italian supply lines until shortage of spares and fuel forced their withdrawal. In June 1941, Romania joined Germany in its invasion of the Soviet Union. Two squadrons were equipped with the Potez 633 at the time and these were used to support the Romanian army as it advanced through Bessarabia towards Odessa. In 1942 they were replaced in operational use by Junkers Ju 88s, allowing the Potezes to be transferred to the advanced training role.

More than 700 Potez 63.11 were delivered by June 1940, of which more than 220 were destroyed or abandoned, despite the addition of extra machine gun armament; the heaviest losses of any French type. The Potez 63.11 continued in service with the Vichy air force and with the Free French forces in North Africa seeing action with both. Production was resumed under German control and significant numbers appear to have been impressed by the Germans, mostly in liaison and training roles.

All members of the family (possibly except the Potez 63.11) shared pleasant flying characteristics. They were well designed for easy maintenance and later models had a heavy armament for the time (up to 12 light machine guns for the Potez 63.11). They were also quite attractive aircraft. Although not heavily built they proved capable of absorbing considerable battle damage. Unfortunately the Potez 63 family, like many French aircraft of the time, simply did not have sufficiently powerful engines to endow them with an adequate performance. In the stern test of war they proved easy meat for prowling Messerschmitts, like their British contemporaries the Fairey Battle and Bristol Blenheim (again, both dedicated bombers). Their similarity to the Bf 110 (twin engines, twin tail, long "glasshouse" canopy) was sufficient that some were apparently lost to "friendly fire".

Variants
Unlike many contemporary French aircraft, production of the Potez aircraft was reasonably prompt and the first deliveries were effected before the end of 1938. The 63 has been designed with mass production in mind and as a result, one Potez 630 was cheaper and faster to manufacture than one Morane-Saulnier M.S.406. As production tempo increased, a number of derivatives and experimental models were also developed.

Fighter variants
A typical feature of the 630 and 631 was the frontal armament, which originally consisted in two 20 mm Hispano-Suiza HS.404 cannons in gondolas under the fuselage, though sometimes one of the cannons was replaced by a MAC 1934. Later in their career, 631s received four similar light machine guns in gondolas under the outer wings, though it was theoretically possible to fit six.


 * Potez 635 CN2:night fighter project was cancelled
 * Potez 63.12 C3:with Pratt & Whitney Twin Wasp Junior radials remained a single prototype
 * Potez 670-01:Fighter prototype
 * Potez 671:heavy fighters were on the assembly lines when the Germans captured the SNCAN Méaulte factory near Albert.

Prototypes

 * Potez 63.01:The first prototype
 * Potez 630.01:The second prototype
 * Potez 630 CN.2 No.01:Night-fighter prototype
 * Potez 631.01:The first Gnome-Rhone powered prototype.

Trainer variants

 * Potez 634:A dual control trainer aircraft derivative of the 630 was proposed, which was simply designated as
 * Potez 631 Ins: (for instruction) 630 conversion with Gnome-Rhône engines
 * Potez 63.16 T3:A crew trainer derivative of the 63.11 with different, larger wings. Only one prototype was built.

Bomber variants

 * Potez 633 B2:two-seater, light level bomber. The Potez 633 retained the fuselage, wings and engines of the 631 but the observer's position and cannon gondolas were deleted and a small bomb bay was added between the pilot and rear gunner. Front armament consisted of a single light machine gun in the nose. The bomb bay could house eight 50 kg-class or two 200 kg -class bombs. There was no bombardier position, as the rear gunner was supposed to direct the bombing run through a periscopic bombsight fitted ahead of him, a disposition that proved unworkable in the field.
 * Potez 633.01:The first two-seat bomber prototype flew in late 1937. The Armée de l'air ordered 133 Potez 633s in 1938, but two months later decided all aircraft in the light level bomber category should be 3-manned, like the Douglas DB-7 and Bloch MB.175. The French order for 633s was converted into an order for more 631s. The 633 was however offered for export and attracted orders from Romania, China and Greece.


 * Potez 632 Bp.2:One example of the dive bomber prototype was started, but completed as a 633 however with Hispano-Suiza engines. It was sold to Switzerland for evaluation.
 * Potez 639 AB2:The single two-seat attack bomber prototype was converted as a standard 633.

Reconnaissance variants
Dissatisfied with its strategic reconnaissance aircraft such as the troublesome Bloch MB.131, the Armée de l'air required the development of a derivative of the Potez 631 for this role.
 * Potez 637:Strategic reconnaissance aircraft. The observer was housed in a gondola under the fuselage; this arrangement resulted in an aircraft that retained most of the qualities of the 631. 60 examples were ordered in August 1938 and delivered.

At the same time, the Armée de l'Air was desperate to re-equip its army cooperation units which had particularly antiquated equipment, but since the development of the 637, had completely changed its mind about how the observer position should be arranged. Potez was therefore required to develop a variant that, while retaining the wings, engines and tail surfaces of the 631, hosted the observer in a more conventional nose glasshouse.


 * Potez 63.11:Because the pilot needed to be seated above the observer, the fuselage was taller, which resulted in degraded top speed and manoeuvrability. As a result the 63.11 proved very vulnerable, despite being protected with some armour and basic self-sealing coating over the fuel tanks. As a secondary light bomber capability was part of the requirements (though it was rarely if ever used), the fuselage accommodated a tiny bomb bay, carrying up to eight 10 kg-class bombs. This bomb bay was replaced by an additional fuel tank on late examples. Additionally, two 50 kg-class bombs could be carried on hardpoints under the inner wings. Frontal armament was originally one, then three MAC 1934s under the nose, and many 63.11s were equipped with the same additional guns in wing gondolas as the 631s.

The first Potez 63.11 No.1 and second No.2 prototypes first flew in December 1938, and no less than 1,365 examples were on order in September 1939, of which 730 were delivered, making the 63.11 the most numerous variant of the family by far.

Operators

 * Armée de l'Air
 * Aéronautique navale
 * 🇫🇷 Vichy France
 * Armée de l'air de l'Armistice
 * Free France
 * Forces Aériennes Françaises Libres
 * undefined
 * Luftwaffe
 * 🇬🇷 Greece
 * Hellenic Air Force
 * undefined
 * Regia Aeronautica
 * Polish Air Forces on exile in France
 * Depot d'Instruction de l'Aviation Polonaise at Lyon-Bron operated two Potez 63.11 aircraft.
 * 🇷🇴 Romania
 * Royal Romanian Air Force
 * Swiss Air Force - One Potez 630C.3 and one 632B.2 aircraft.
 * Kingdom of Yugoslavia
 * Yugoslav Royal Air Force
 * Swiss Air Force - One Potez 630C.3 and one 632B.2 aircraft.
 * Kingdom of Yugoslavia
 * Yugoslav Royal Air Force

Civil operators

 * 🇫🇷 Air Bleu (two aircraft converted into mail carriers)