Kompiuterinis geometrinis sklandytuvo Lak-17 modelis sugeneruotas programa AVL, kuri skirta orlaivių konfigūracijos ir skrydžio charakteristikų analizei. Imituojant realų skrydį programa suskaičiuotos įvairios šoninio stabilumo charakteristikos. Tirta, kaip šoninio stabilumo savyb÷ms, tokioms kaip krypties nestabilumas, spiralinis nestabilumas, „olandiškas žingsnis“, turi įtakos skersinio V kampo didinimas ar mažinimas, vertikalios uodegos plokštumos ploto keitimas. Pagal gautus rezultatus suformuluotos išvados kiekvienam šoninio nestabilumo atvejui. Darbą sudaro 3 dalys: įvadas, problemos analiz÷, AVL programos apžvalga, tyrimas, išvados, literatūros sąrašas. Darbo apimtis – 92 p. 65 p. teksto be priedų, 82 iliustr., 6 lent. Atskirai pridedami priedai. / Computer-based geometrical model of sailplane Lak-17 was generated with a program AVL (Athena Vortex Lattice), which is designed for analysis of characteristics of flight and rapid analysis of configuration of aircraft. Analysis was done how increasing and decreasing of wing dihedral and exchange of vertical tail area characteristics are influenced on lateral stability like directional divergence, spiral divergence and „dutch roll“. Simulating a real flight with the program various characteristics of stability and control were calculated. According results the conclusion was formulated for every case of lateral unstability. Structure: introduction, problem analysis, AVL overview, research, conclusions, references. Thesis consist of – 92 p. 65 p. text without appendixes, 82 pictures, 6 tables. Appendixes are included.