M.Hardy. Gliders & Sailplanes of the world

Antonov A-11

  Oleg K. Antonov first became known as a glider and sailplane designer in 1930, and his best known prewar design was the high-performance single-seater known as the Red Front 7, which was used by O. Klepikova to set up a women's distance record on 6 July 1939 with a flight of 465.25 miles from Moscow to Otradnoie, near Stalingrad; this record stood for no less than 38 years. Other Antonov designs were the A-1 single-seat elementary training glider, the A-2, a modernised version of the US-5 two-seat training glider, and the A-9 and A-10 single and two-seat high-performance sailplanes. The A-11, which first flew in prototype form on 12 May 1958, is a high-performance single-seater which followed the practice of US manufacturers such as Bryan and Schweizer in being of all-metal construction. The well-streamlined forward fuselage housing the pilot under a blown plastic canopy tapers to a slim boom carrying the cantilever butterfly tail, with an included angle of 90' between the tail surfaces. The A-11 is aerobatic and suitable for both spinning and cloud flying, and the mid-set wing has a single spar in the root and two spars in the outer wings. The leading edge is metal-covered, with fabric covering aft of the main spar. The fabric-covered slotted ailerons can be drooped through 8' to supplement the slotted flaps, and there are also lift spoilers on the wing upper surfaces. The monocoque fuselage has a retractable sprung monowheel and a rubber-mounted tailskid.


Data: A- 11
Span: 54 ft 1 1/2 in
Length: 19 ft 8 1/2 in
Wing area: 130.8 sqft
Aspect ratio: 22.4
Empty weight: 648 lb
Max take-off weight: 882 lb
Max speed: 217 mph (in smooth air)
Max aero-tow speed: 124 mph
Min sinking speed: 2.43 ft/sec at 53.5 mph
Best glide ratio: 32:1 at 60 mph



Antonov A-13

  Developed in parallel with the Antonov A-11, and making its first flight exactly a week before the latter the A-13 utilises the same fuselage, undercarriage and tail unit as the A-11 married to a shorter span (39ft 8 1/2 in) wing of lower aspect ratio for aerobatic training. This wing is very similar in construction to the A-11's, with a single spar in the root and two spars in the outer wings, and fabric covering aft of the main spar, but flaps are not fitted and the fabric-covered ailerons are not slotted. There are lift spoilers in the upper surfaces. The shorter span wing results in a higher wing loading of 7.07 lb/sq ft and a much higher minimum sinking speed of 3.74 ft/sec. Altogether about 350 examples of the A-11 and A-13 were built.


Data: A-13
Span: 39 ft 8 1/2 in
Length: 19 ft 8 1/2 in
Wing area: 112.4 sqft
Aspect ratio: 13.8
Empty weight: 560 lb
Max take-off weight: 794 lb
Max speed: 217 mph (in smooth air)
Max aero-tow speed: 124 mph
Min sinking speed: 3.74 ft/sec at 60mph
Best glide ratio: 25:1 at 70 mph



Antonov A-15

  The single-seater A-15 is a high-performance Open Class design of all-metal construction like the A-11 and A-13 but considerably more refined than these earlier types, and capable of aerobatics, spinning and cloud flying. The prototype first flew on 26 March 1960 and the A-15 soon set up a number of records, including the World goal flight distance record of 443 miles in June 1960. The mid-set wing has a single aluminium main spar of box section, and there is a 50 litre (13.2 gal) water ballast tank built into the wing; wing covering is all-metal. The light alloy ailerons and Fowler flaps have plastic foam filling between the ribs, and there are lift spoilers on the wing upper surfaces. Small end-plate fairings called 'salmons' can be fitted on the wing tips. The fuselage is a light alloy semi-monocoque structure and the sideways-opening blown plastic canopy opens to starboard. The pilot's back-rest and rudder pedals are adjustable, and there is provision for oxygen and radio. Landing gear consists of a retractable sprung monowheel with brake. The cantilever butterfly tail has an included angle of 90° between the tail surfaces; the tailplanes are of light alloy and the elevators of mixed alloy and wood construction with fabric covering.


Data: A-15
Span: 55 ft 9in
Length: 23 ft 8 in
Wing area: 132 sqft
Aspect ratio: 24
Empty weight: 661 Ib
Max take-off weight: 838 lb
Max speed: 155 mph (in smooth air)
Max aero-tow speed: 87 mph
Min sinking speed: 2.07 ft/sec at 56 mph
Best glide ratio: 40:1 at 62 mph