Ikarus AD Kosava
The Kosava (or North Wind) was a high performance two-seater intended to replace the DPS Kranich then in use in Yugoslav clubs; its design was commissioned by the Yugoslav Flying Sports Organisation from Milos Ilic and Adryan Kisovec, and the prototype made its first flight in March 1953. A few weeks later Bozo Komac flew it to victory in the Yugoslav National Championships, and the type went on to win many prizes in contest flying in the two-seater class, taking first place in this category in the 1954 World Championships at Camphill, Bedfordshire, and second place in the 1956 World Championships at St Yan in France.
Of conventional wood and fabric construction, the Kosava had a shoulder-mounted gull wing with a slight forward sweep at the leading edge and a more marked trailing edge sweep; the forward sweep served to maintain the cg at a suitable place when the Kosava was being flown solo. The ailerons were divided into inner and outer halves, and underwing spoilers were fitted, as well as trailing edge flaps which operated in conjunction with the ailerons, being used separately during landing. The second prototype Kosava was fitted with Schempp-Hirth air brakes. The two pilots are seated in tandem under a two-piece canopy and the landing gear consists of a single skid under the forward fuselage.
The Kosava-2 was a redesigned version intended for training from basic to advanced levels, including blind flying training, aerobatics and high altitude soaring. It features a new more streamlined fuselage with the pilots in tandem under a flush-fitting cockpit canopy divided by a centre frame; the two canopy sections are jettisonable, and there is provision for an oxygen system for the pilots. A retractable monowheel and tail bumper replaces the skid of the earlier Kosava, and the fin and rudder are swept back and the mid-set tailplane's span increased, whereas the earlier Kosava's tail unit, fuselage and cockpit resembled those of the DPS Kranich it was designed to replace. The Kosava-2's wing is very similar in plan to the earlier Kosava's, but has dihedral from the roots and is of 18m span (59 ft 0.75 in), with one piece ailerons, air brakes in the upper surfaces and no flaps.
Span: 62 ft 9 in
Length: 27 ft 4 in
Wing area: 227.4 sq ft
Aspect ratio: 17.3
Empty weight: 741 lb
Max weight: 1,268 lb
Max speed: 136 mph
Min sinking speed: 2.17 ft/sec at 46.5 mph
Best glide ratio: 33.5:1 at 54 mph