Pilot's Post - Race planes of the thirties, the Potez 53

06.11.2022

Powered by a supercharged 9-cylinder 488.2 cu in (8.000 L) the French Potez 9B air-cooled radial engine driving a two-bladed fixed pitch propeller. The Potez 53 was a French low-wing enclosed cockpit single-seat cantilever monoplane racing aircraft built by Potez to specifically compete in the 1933 Coupe Deutsch de la Meurthe race, which it won outright.

The engine was specially designed for the competition, which limited displacement to 8 liters (490 cu in). The primary structure and covering were wood. The undercarriage retracted outwards into the undersides of the wings while the tailskid was fixed.

Two machines were entered for the 1933 Coupe Deutsch de la Meurthe. The first (racing no.10) was flown by Georges Détré, who won the race, covering the 2,000 km (1,200 mi) closed-circuit course with an average speed of 323 km/h (201 mph). The other (racing no.12) was flown by His compatriot Gustave Lemoine flew number 12, unfortunately had to retire at the end of the fourth lap.

Following this success the Potez 533, a new design with various improvements was built for the 1934 race. Improvement in the 533 included an uprated engine delivering 350 hp (260 kW) driving a Ratier variable-pitch propeller, slimmer and more streamlined fuselage and redesigned wings of increased area.

One of the two older aircraft was refurbished as the Potez 532 to act as a backup in the competition. The engine was uprated, its fuselage was slightly lengthened for aerodynamic reasons, the wing was further enlarged and additional flaps were installed between the fuselage and ailerons.

The two aircraft were flown by the same pilots as the previous year, but neither completed the 1934 race. Gustave Lemoine, who was flying the new Potez 533 completed ten 100 km (62 mi) circuits with an average speed 368 km/h (229 mph) before being forced to withdraw due to a problem with the variable-pitch propeller. Georges Détré, who was flying the older machine completed only eight circuits before a broken oil pipe forced him to abandon the race.

Photo by Pline SA 3.0 commons.wikimedia.org

The unmodified Potez 53 which won the 1933 race is preserved in the Musée de l'Air et de l'Espace in France.

Specifications (1933 Potez 53)

General characteristics

Crew: 1
Length: 5.40 m (17 ft 9 in)
Wingspan: 6.65 m (21 ft 10 in)
Height: 1.80 m (5 ft 11 in)
Wing area: 7.20 m2 (77.5 sq ft)
Empty weight: 600 kg (1,323 lb)
Gross weight: 900 kg (1,984 lb)
Powerplant: 1 × Potez 9B supercharged 9-cylinder 8 L (490 cu in) air-cooled radial engine, 230 kW (310 hp)
Performance
Maximum speed: 356.0 km/h (221.2 mph, 192.2 kn)
Wing loading: 125.0kg/m2 (25.6 lb/sq ft)
Power loading: 2.9kg/hp (6.39 hp/lb)

History
Classic Aircraft

Race planes of the thirties, the Potez 53

By Willie Bodenstein