How many basic parts make up the L-39's structure?

The L-39 Albatros was designed as a low-cost jet trainer, also capable of ground-attack missions. Its construction is modular: the airframe breaks down into just three major subassemblies — wing, fuselage, and rear fuselage with the tail assembly — to make major maintenance and overhauls easier. The complete wing, except for the movable surfaces, is a single piece and includes the permanent tip tanks. The swept fin is integral with the rear fuselage, and the latter can be removed for easy access to the engine.

Counting the removable elements — nose cone, control surfaces, landing gear, and cockpit canopies — the entire L-39 airframe amounts to little more than two dozen basic components. That arrangement allows any of them to be replaced quickly and easily, and the aircraft has numerous access panels for reaching specific systems or equipment.

The low, straight wing has a double-taper planform, 2½ degrees of dihedral from the root, and a relatively low aspect ratio. A long, pointed nose leads to the tandem cockpit, where student and instructor sit. The retractable tricycle landing gear is hydraulically actuated and designed to operate from grass strips. The L-39C was the standard basic trainer version for the Soviet Union, Czechoslovakia, and export. The L-39ZO was a provisional armed trainer variant for export, and the L-39ZA was a much-improved ZO for armed training and light attack, with sturdier landing gear.