Potez 637A3. - reconnaissance version of the Potez 63 multipurpose aircraft. The initial specification stipulated the creation of a multipurpose aircraft that combined the functions of a heavy fighter, a long-range reconnaissance aircraft and a light bomber, therefore work on the Potez 63 project was carried out in three directions at once. The "long-range reconnaissance" modification, later designated Potez 637, was structurally similar to the Potez 630 fighter.

The main difference was only in the installation of the ventral nacelle, in which the observer was located in the recumbent position, and in the engines Gnome-Rhone 14M-6. The composition of the armament was reduced to one 7.5-mm MAC 1934 machine gun installed in the front of the fuselage, one 7.5-mm movable machine gun in the gunner's cockpit and one of the same machine gun for protection from the tail side.

The first and last order for 60 Potez 637A3 aircraft was issued in August 1938 - even before the first flight of the prototype. Tests of the prototype began in October, by the end of 1939 it was planned that the Potez 637A3 would still be able to completely replace the outdated Potez 542 in long-range reconnaissance groups. This idea was not fully realized. In total, by the beginning of the Second World War, there were 53 Potez 637 reconnaissance aircraft as part of four reconnaissance groups. The aircraft that entered service required maintenance, while there were sorely lack of spare parts and engines. As a result, the number of combat-ready Potez 637 did not exceed 40%, which forced the Potez 542 to be kept in service until the summer of 1940.

Armament. One fixed forward-firing 7.5 mm machine gun in the nose of the fuselage (300 rounds) and one movable (500 rounds) and one stationary (300 rounds) machine guns firing backward.

Photo	Description
	Drawing Potez 637

Bibliography

• Heavy fighters of the Second World War. / Aviation collection. Planes of the World /
• French Aircraft of World War II /Aviafrance./