Antonov A-9

Antonov

Industry	Aerospace
Founded	1940s
Headquarters	USSR

The Antonov A-9 was a single-seat sailplane produced in the USSR during the 1940s, evolving from the record-breaking Red Front 7.

Design and development

Since the early 1930s, Oleg Antonov had been involved in designing sailplanes, most notably the Red Front 7, which set a world distance record of 749 km (465 mi) piloted by Olga Klepikova—a record that remained unbroken between 1939 and 1951. The A-9 is regarded as an advancement of this earlier model, although detailed documentation from this era of Soviet Union aviation remains scarce. The two gliders shared similar fuselage and tail designs; however, their wings differed significantly.

The A-9 featured a cantilever, shoulder wing monoplane configuration. Its wing planform included a short, constant chord center section combined with elongated, straight-tapered outer panels. Both leading and trailing edges were swept, culminating in rounded wingtips that curled downward. For ease of transport, the outer panels were detachable from the center section. Notably, the center section was integrated into the fuselage structure itself, with a single box spar spanning the 3.2 m (10 ft) center section uninterrupted. This spar extended beyond the joint connecting the center and outer panels. The entire wing was covered with plywood ahead of the spar and finished with aircraft fabric covering behind it. The outer panels housed long-span, tapered, fabric-covered, and mass-balanced ailerons occupying about two-thirds of their trailing edges. Additionally, these panels incorporated Schempp-Hirth-style airbrakes, positioned just aft of the spar and ending at the panel junction. The wing’s airfoil was thick and slightly reflexed toward the rear, with its maximum thickness located near 20% chord from the leading edge, resulting in a pronouncedly steep nose profile.

The A-9’s fuselage was plywood-covered and oval-shaped in cross-section—deep forward of the wings and nearly circular toward the rear—giving it a distinctive pod-and-boom silhouette. The fixed tail surfaces were also plywood-covered; the narrow fin featured a small fuselage fillet. Control surfaces were fabric-covered. The horizontal tailplane was tapered with swept leading and trailing edges in plan view. The broad, curved, balanced rudder extended down to the keel and was hinged well aft—nearly aligned with the elevator’s trailing edge—to provide adequate clearance and control moment. The upper fuselage line remained almost flat along its length, including over the rear section of the long two-piece canopy, although its windshield sharply curved downward into the nose area. Instead of a skid or wheeled undercarriage, the A-9 was launched using a wheeled drop-off dolly and landed on an internally reinforced underside of the fuselage supported by a tail bumper.

Due to its robust construction, the A-9 exhibited a relatively high structural weight resulting in a wing loading of 30.5 kg/m² (6.2 lb/ft²). For comparison, contemporaneous gliders such as the Slingsby T.25 Gull 4 had lower wing loadings around 22.3 kg/m² (4.6 lb/ft²). Elevated wing loading values allow for increased speed and improved glide ratios between thermals but tend to reduce climbing efficiency in weak lift conditions. While it is documented that water ballast was used on the Red Front 7 during its record-setting flight to optimize performance, no such ballast system was installed on the A-9.

Operational history

Owing to their high velocity, the A-9 models were primarily utilized for competitive flying and establishing new records.

Variants

Information sourced from Sailplanes 1945–1965

16.24 m (53.3 ft) wingspan

Base model.

16.50 m (54.1 ft) extended wingspan

This version featured a 10 kg (22 lb) increase in weight, while maintaining a standard useful load of 100 kg (220 lb). The wing area was reduced to 12.2 m² (131 sq ft), resulting in a wing loading of 34.5 kg/m² (7.0 lb/ft²). It is possible this variant was designated the Antonov A-10, although some references attribute that name to a two-seat derivative of the A-9.